What about our rivals?

[Motorhead350]

Does anyone know what a blown 94-96 Impala will run, it is common to do and do they keep up with us, or get smoked or do we get smoked? I speaking of comparing a blown Marauder to an Impala with not other major mods. Anyone know?

[mcb26]

Someone from SSHS5 should be able to answer this.:burnout:

[Smokie]

It would difficult to find a blown Impala with no other mods, they usually start with bolt-ons and go from there.

In theory, if the blowers are equal, the displacement advantage would tip the scale in favor of the Impala.

That's what I think.;)

[Blackened300a]

Lets Say its Vortech vs Vortech with 9psi each. Is it possible that because we have more intake and exhaust valves in the heads that we are allowing more supercharged air to the cylinders which would in turn give us a more complete combustion and resulting in more power then the 2v Push Rod Chevy Boat Anchor known as the LT-1?


Just a thought

[SergntMac]

Lets Say its Vortech vs Vortech with 9psi each. Is it possible that because we have more intake and exhaust valves in the heads that we are allowing more supercharged air to the cylinders which would in turn give us a more complete combustion and resulting in more power then the 2v Push Rod Chevy Boat Anchor known as the LT-1? Just a thought Bravo, dude! Best way to look at this comparasion, eh?

Whether it's the LT-1 (350 CID), or, the Intech 4V (281 CID), the power adder is external. 9 PSI makes it all simply a matter of an induction pipe delivering a supercharged air/fuel mixture to the combustion chamber, yes? And I think this is a fair comparasion to explore, just for gits and shiggles...

I think the 4 valve DOHC engine would perform better than the 2 valve push rod engine. Better, and so much better that we could say "no contest."

If I remember my math from the old daze, a small block pushrod engine will max out at 8000 RPM., and this is a race built maximum output engine. A 4 valve DOHC engine, likewise race built and maxed out, can run up to 12,000 RPM, and continue to produce power for another 4000 RPM past the capabalities of the pushrod engine. We may not share these engines in our street machines, but we do share the benefits of others exploring this technology.

A 4 valve DOHC engine will beat a 2 valve single cam engine any second of the year, despite the 70-ish CID difference. What the 350 earns in low end torque, the 281 earns in high end breathing. The power you make in the first half of the quarter mile race, must be enough to overcome the power made in the second half of the 1/4 mile race, and a small block single cam pushrod engine cannot make the power a 4 valve dual overhead cam engine produces. No lungs...

This is why 60 foot and 330 foot times are so important to some members here as stats. These are the times/MPH to watch when on a short race 1/8th mile track. But, if you want to see what's what, stick to the long run and 1/4 mile times and speeds. Watch the 1000 foot times and MPH, and the trap times and speed?

Any heavy car that gains 35 MPH in the second 1/8 mile, is quick, and will most likely be the victor. Makes me wonder...How would any of us do in a full one mile race? Or, a race that called for 10 miles or more over 6000 RPM? Over 100 MPH?

Just wondering...Back to our regular programming, eh?

[Marauderman]

Where do I sign up??==This sounds good --if but a thought!! I can
dream thinking about this stuff--Gotta be the biggest thrill --almost a cannon ball .....in a short way--

[Smokie]

I completely agree with Sarge...better lungs. I was not sure about the scope of the original question so I went with what the majority of us do with their cars.... the stop light grand prix and the 1/4 mile.

Within that limited scope, I still would give the edge to the S/C push rod engine....I also know for a fact that if you keep running just slightly past the 1/4 mile...32 valves win every time......:D

[Blackened300a]

Within that limited scope, I still would give the edge to the S/C push rod engine....I also know for a fact that if you keep running just slightly past the 1/4 mile...32 valves win every time......:D

That seems to be the case with every 32v engine. One of my friends had a 96 Impala with minor bolt-ons. He pulled a 14.7 at the track with it. One night while I was with him, a 96 or 97 Caddy STS lined up next to us and we went for it, We were ahead of the STS by a car length til about 75mph and then the STS starting gaining, by the tme we reached 100 mph the STS was a bumper ahead, at that point we slowed down and my friend said this "By the time he caught us, we already passed the 1/4 mile mark so my car is faster" We then started the definition of Quicker and Faster Argument.

If it was a long distance top speed run
Cadillac STS (32V Northstar) 1
Impala SS (2v LT-1) 0

[Motorhead350]

Thanks I learned something

[BillyGman]

Sorry, but I don't think that you've "learned" anything (yet:D ). I disagree with MAC. Try racing those Impala SS guys who are S/Ced, and then tell me what you think. Everything else being equal, 70 extra cubic inches means a real lot. More than having 2 extra valves per cylinder does. The only way that having a 32 valve engine would work in your favour, is if both the pushrod and DOHC engines in question had the same displacement.Claiming that an engine has more power potential simply because it also has more RPM potential is exactly what the ricer boys think about our cars vs their four cylinder sowing machine engines. Until they race one of us that is.

I've driven one of the LT1 equipped cars for a good part of a week as transportation, and I've raced up against the Impala SS boys. Their extra 70 cubes means a lot. Just go to their timeslips page and look at what their S/Ced cars are doing. We have one 10 second Marauder amongst us, along with three or four 11 second ones. They have anumber of 10 second and even 9 second S/Ced Impalas amongst them, and a multitude of 11 second ones. In fact,last time I looked, some of their 11 second Impalas are naturally aspirated!!! Let me seee you get a naturally aspirated Marauder into the 11's. Nobody has even gotten them into the 12's.

The only thing in our favour is that on the street, you would be hard pressed to find very many Impalas that are S/Ced, because their stock LT1 bottom ends cannot hold up as well as the Marauder bottom ends do in S/Ced applications. One reason for that is because the stock connecting rods are weak. And that's due to the beams on them having been made thinner. Chevy skimped on the connecting rods, and so that's one of the inherit weaknesses of the bottom ends of the LT1 engines. Compared to small block Chevy's of the early 70's, the 80's and 90's small block Chevy's connecting rod beams are .060" to .080" thinner. But that's a durability issue, and not directly a power issue. Those engines make good power. Torque wins drag races, and those engines have that.

[merc6]

I testdrove the 96 ss up against the MM and the ss spun tires but didn't move like the MM did. Hell how they get them that fast? didn't the 96 weigh in more than the 64?

[Blackened300a]

I can only think that the Impala guys are way ahead of us on the performance technology due to the fact that the LT-1 has been around so much longer and have so many more aftermarket performance parts then our engines do. Competeing with the LT-1 since its been in almost every GM V-8 Rear Drive car since the early 90's ,Buick,Cadillac,Pontiac and Chevy, against a aftermarket performance line of a engine thats just started to get life recently in Mustangs, Marauders and now the Aviator its obvious who has had more time to learn the inside and out of the engine and knows what works with so many years of trial and error.

Would it be fair to ask that if we had over 20 years of experience and aftermarket parts with this engine, Would they still be so much faster then us??

[SergntMac]

The question morphs yet a third time.

Okay...All other concerns being equal, which would perform better? 70 cubic inches of displacement, with a single cam/pushrod, or, 4 valves per cylinder with dual over head cams?

[Blackened300a]

The question morphs yet a third time.

Okay...All other concerns being equal, which would perform better? 70 cubic inches of displacement, with a single cam/pushrod, or, 4 valves per cylinder with dual over head cams?

Definitly with out a shadow of a doubt, 4 Valves per cylinder with dual overhead cams. The concept of getting more power out of a engine is how fast you can get Air in and Exhaust out. 4 valves are putting twice as much air in and pushing twice as much exhaust out then the 2 Valve Chevy LT-1.
The only good thing about the LT-1 is the fact that a push-rod engine is a low interference engine. if something lets go in a 4v engine. Get the checkbook out cause it wont be a cheap and easy fix.

[TripleTransAm]

I think it depends on the interpretation of "perform better". Are we talking top end? Overall grunt? Better efficiency (power per unit fuel consumed)? Durability? And then comes the application of this motor: a top end motor obviously works better in a light car, does it make it less of a performer overall? What about a good motor attached to an inefficient drivetrain that just sucks up too much in losses?

We could argue for years and not come up with a definitive answer. If the answer was clear, there would be no need for automakers to spend money on R&D, the answer would already be there.

I think it's not possible for all other concerns to be equal, because there are so many variations of the other parameters that make them incompatible between OHV and OHC engines. Stuff like port design, combustion chamber design, head cooling, etc.

I know I keep bringing up the LS1, it's because that's the motor I am familiar with... 4 less cubic inches than the LT1 with the same basic layout, yet note the change in explosive top end performance versus the negligeable loss in sub-1500 RPM torque (maybe 10 lb-ft?). And then the LS2 comes along and turns the LS1 into a relative boat anchor with just a few extra cubic inches and some tweaking here and there. So my point is that we can't really compare the two valvetrain approaches on a blank sheet of paper: you really have to compare the total packages as put together by the manufacturers.

[BillyGman]

The definaition of "performs better" would have to be dragstrip ET's, and you can have all the valves you want, but 70 exta cubes of displacement is simply more room to move more air. Just look at the new 2006 Z06 Vettes. more displacement, 2 valves per cylinder, and pushrods= more power & 11.5 second ET's right out of the showroom. I don't think that the 2007 GT500 even with it's S/Cer will be doing that.

[SergntMac]

The definaition of "performs better" would have to be dragstrip ET's, and you can have all the valves you want, but 70 exta cubes of displacement is simply more room to move more air. Valid point, but it depends on getting more air into the larger displacement too. I'm not a gambling man, but I'd put my money on the 4 cam/4 valve. I don't believe we have scratched the surface of capability for the DOHC engine, better things are coming

[TripleTransAm]

One thing we're not taking into account when we use the 'moving more air' argument with DOHC 4V heads... what's going to get that air moving? Air doesn't move by itself, nor is the engine an 'air pump' that exists solely to pump air in and out.

Yes, the cylinder draws air in and expels spent gasses out, but the whole point of it is to deliver twisting force through the crankshaft. The energy to draw in and expel this air is energy subtracted from getting the car moving, which is ultimately the whole point of existence of this motor. What it does with that air/fuel mixture that it ingests is the key: if the combustion is healthy and efficient, you get the most power produced, and how much of it gets out of the motor and to the wheels is dictated by how much is soaked up in trying to move internal parts and draw/expel air.

And then the keys to efficiency within the combustion process are compression ratio and proper timing. And to benefit from these, you need a good cylinder design that will allow the most aggressive combustion for the fuel used. Pulling timing due to knock is not going to give you a good yield on that intake charge, regardless of whether you have sewer-sized intake ports or not. Similarly, density of that intake charge will play a large role in how much energy is released during combustion... hot intake paths or hot spots will not help at all.

So to illustrate my argument, let's use fictitious numbers: say a combustion process produces 100 units of energy. Let's say it takes 50 units of energy to keep itself running (pumping losses, friction, etc.). That's 50 net units. Take another motor that puts out 150 units from a slightly bigger displacement, but its less efficient intake path uses up 80 units. That's still 70 units net. Make that motor smaller and address little improvements in efficiency here and there, and you might just get say 130 units gross but with losses trimmed to 60 units... that's still 70 units net.

I'm sure there must be other factors, too... if it was that much easier to produce big numbers from a V8 using multi-cam OHC technology, we'd be seeing lots more Northstars across the GM lineup pushing out bigger numbers than the pushrod motors. (Have you guys SEEN the size of the ports on the LS1? these things BREATHE up top, don't make any mistake about it...)

As for the capability of the DOHC engine, I think the surface has been scratched quite a bit in recent years. Honda's VTEC V6 as used in the previous generation Acura 3.2 TL-S is a good example: the VTEC (variable valve timing) delivered increased top end power AND a hefty low end boost in torque, over the basic non-VTEC DOHC V6 in the base 3.2 TL. We wouldn't have to be worrying about changing gears and torque converters and bumping up the spark curves along with lower temp thermostats in a quest for low end torque improvements if Ford had put some money into variable valve-timing and eliminating overheating heads with single knock sensors. It's all there to be implemented, no extra R&D necessary, no new ground to cover. That's why I say one has to compare overall packages instead of comparing individual technologies.

[Motorhead350]

You know I forgot about the net power and stuff no one has said that to me sense high school. One thing though i was typing about just a blower on the car and not what it can do naturally. So I guess the Impala has more potential because that engine is more popular and common. I never heard of a 11 second natural Impala but I knew of one running a 12.8 however it was a LT1 not an Ls1. So anyway I guess this question can never really have a good answer until we do an actual test.

[BillyGman]

Just a side note: the 94-96 Impala SS cars came with LT1 engines. The LS1 engines didn't come out until 97, and by then the RWD V8 Imapala was gone. The LS1 engines are more potent than the LT1 engines were because of their superior cylinder head design. But that's another story for another thread I guess.

As far as driving on the street goes, it seems to me that RWD Impalas have dwindled in numbers significantly, simply because it's been ten years since their production came to a halt. So on the street, you usually don't have to be concerned with an Impala SS lining up next to you at a traffic light. I see more Marauders on the street than I do RWD Impalas.

[Blackened300a]

So on the street, you usually don't have to be concerned with an Impala SS lining up next to you at a traffic light. I see more Marauders on the street than I do RWD Impalas.

This is inaccurate here in NY. I can see a Impala SS a lot more often then a Marauder here. I can go days without seeing a MM here.

[SergntMac]

This is inaccurate here in NY. I can see a Impala SS a lot more often then a Marauder here. I can go days without seeing a MM here.Likewise here in Chicago. I see at least one Impala SS every day, there are 3 parked in the HQ parking lot daily. Marauders? Well, when I meet up with friends, and there's one at the firehouse on 111th on a regular basis, but I never met the owner.

/Steve, thanks for the thoughtful post on emerging technology. As usual, you lay out a thought provoking outlines.

[Bradley G]

I don't think the GT 500 will be doing 11.5 off the showroom either.
Maybe 11.9's,,,,,,,,,Different strokes!!! not too shabby!
The definaition of "performs better" would have to be dragstrip ET's, and you can have all the valves you want, but 70 exta cubes of displacement is simply more room to move more air. Just look at the new 2006 Z06 Vettes. more displacement, 2 valves per cylinder, and pushrods= more power & 11.5 second ET's right out of the showroom. I don't think that the 2007 GT500 even with it's S/Cer will be doing that.

[metroplex]

Ford could just throw more valves at the engine. :P

In a few years, we'll be at like 7.5 valves per cylinder becuase they add a few, then take a few away as time goes on.

[thePunisher]

to say (generally) that a smaller 4 valve engine is weaker than a larger 70 ci pushrod motor is not very accurate...got to compare apples to apples. 70 more cubes dont mean a damn thing if the heads dont breathe and the cam sucks....both of which are characteristics of the lt1. it was a torque monster and that was its only benefit. engine was completely dead above 4000rpms. the 4.6 4 cam FORD engine is a strong free revving engine that is a world apart from the lt1. they both have their benefits and drawbacks. but both engines could be equipped differently to make them stronger at their weak points. a 4 valve engine can make just a smuch torque as a pu\shrod engine if is is equipped to do so. and the same for the chevy...a good set of heads would wake that engine right up on the high end. there is a give n take with everything....sorry im rambling...anyway...put the same amount of boost in both engines and id say the chevy aint got a prayer....at least the ford heads breathe a bit....the lt1 cam and heads cant move any air as it is...then were gonna shove 9 #s boost in it??....no contest...ford all the way...

[Smokie]

............................

[Todd TCE]

Likewise here in Chicago. I see at least one Impala SS every day, there are 3 parked in the HQ parking lot daily. Marauders? Well, when I meet up with friends, and there's one at the firehouse on 111th on a regular basis, but I never met the owner.

/Steve, thanks for the thoughtful post on emerging technology. As usual, you lay out a thought provoking outlines.

Ditto that here in Phoenix.

I never did find a local car/owner here for my brake fit work even. I gave up and bought a complete spindle to do it on the bench! Sorry guys, but if it's a car count the Imp wins here.

As for the comparing of times/hp/power etc how can you compare cars with such mods? I don't lean one way or the other here but the theme of the thread is 'how much power can he build'. What are the bone stock numbers? That's a fair question. With builds there are far too many variables to consider. For the curious; what are the stats anyhow?

[Merc-O-matic]

This is inaccurate here in NY. I can see a Impala SS a lot more often then a Marauder here. I can go days without seeing a MM
here.

And here is why...remember the numbers!
There were about 70,000 Impala's built from 1994-95-96
vs. only 11,000 for our Marauder's 2003-04

Gotta Love It!:beatnik:

[merc6]

This is inaccurate here in NY. I can see a Impala SS a lot more often then a Marauder here. I can go days without seeing a MM here.I seem more non stock rwd SS than MM's. Hell when I went looking the damn 96 ss was sitting next to the mm so I could compare both of them on the same strip of road. I also had a co-worker who is from NY wh had one and that thing moved like ***** ape now that I think about it. I do remember us seeing a MM and going damn wish I could afford something like that!

[BillyGman]

...at least the ford heads breathe a bit....the lt1 cam and heads cant move any air as it is...then were gonna shove 9 #s boost in it??....no contest...ford all the way...Look at the Impalas timeslips page as far as their S/Ced ET's, and compare it with ours (that is when we get ours back again) and then comment.

If you're gonna say that having 4 valves per cylinder makes up for 20 or maybe even 30 cubic inches of displacement, I'll go along with that. But 70 cubes? No way. If that's what you think, then you haven't raced very many V8 cars with your Marauder other than other Marauders.

[David Morton]

Horsepower is where it's at. Always has been, always will be.

Lot's of guys think torque is where it's at. But torque isn't rpm dependent, it's just a measure of twisting force. But horsepower is a measure of torque and rpms. John Mihovetz has a 5.0 liter engine based on our 4.6 that's making 1600 hp with twin turbos and a lot of rpms.

But for this discussion all we need to do is realise that if an engine is making 350 ft/lbs torque, you can run that through a 1:2 gear reduction and get 700 ft/lbs. It's all about the gears.

To date, I haven't seen one guy on this board take advantage of the awesome potential for rpms this engine is capable of. I've seen dyno graphs of 500 hp at 6000 rpms on S/C engines and I'm thinking, "Just another 3000 rpm and that guy can be at 750 hp." An LT1 won't do 9000 rpm stock without serious valve float from the valvetrain weight. Ours ought to do it all day long with just a spring change at the most. A Chevy small block valvetrain that could do 9000 rpm would cost $5000, girdles, billet aluminum roller rockers, super heavy springs and high dollar valves to take the stress and still the thing wouldn't last long. And then their heads would need porting and flow bench work to get air flow up to task and still the camshaft duration would need to be lengthened, I know ours would too, but not nearly as much because of our four valves. Put that much money into out valvetrains and we'd be capable of 11,000 rpm.

On forced induction engines, the one with the rpm advantage will beat the one with more cubes and still be streetable. He just needs different gearing.

And lastly, I don't see the Impala as a "rival" anyways! It's hasn't got a Caddilac interior. :lol:

[SergntMac]

To date, I haven't seen one guy on this board take advantage of the awesome potential for rpms this engine is capable of. I've seen dyno graphs of 500 hp at 6000 rpms on S/C engines and I'm thinking, "Just another 3000 rpm and that guy can be at 750 hp." An LT1 won't do 9000 rpm stock without serious valve float from the valvetrain weight. Ours ought to do it all day long with just a spring change at the most. A Chevy small block valvetrain that could do 9000 rpm would cost $5000, girdles, billet aluminum roller rockers, super heavy springs and high dollar valves to take the stress and still the thing wouldn't last long. And then their heads would need porting and flow bench work to get air flow up to task and still the camshaft duration would need to be lengthened, I know ours would too, but not nearly as much because of our four valves. Put that much money into out valvetrains and we'd be capable of 11,000 rpm.

On forced induction engines, the one with the rpm advantage will beat the one with more cubes and still be streetable. He just needs different gearing. Seems I pointed this out already, but not in such detail. Thank you for bringing it forward clearly.

One limitation to seeking out higher RPMs is the rate of climb. My engine can build RPMs faster than the EEC can keep up, ditto the tranny. This was one of the compelling reasons behind installing an '04 EEC in a '03 300A. Dual knock sensors and improved software aside, the EEC thinks faster, and all of my 2-3 shift problems got solved. Before the swap, the tranny was helpless at the 2-3 shift, delayed reactions caused it to bang into gear with a frightening thud similar to powershifting a stick tranny. Nothing serious followed, but it was very annoying and hurt ETs.

Back in '04, when I made the swap, many of my dynos were run from a dead stop, which allowed the dyno to chart the shift delays. It skewed the final number,s but I wasn't looking at them anyway. I wanted to see how much time and RPM was spent in shifting gears. It's amazing what you don't know until you see it charted out, and I suggest that any of y'all who are serious about your performance, take a peek at this.

Anyone seeking out 7000 RPM and higher needs to dedicate a lot of cash to that goal, but yes, it can be done. There are alternativs to the OEM EEC, which is what it will take (along with what has been stated ^ there), but it can be done. Perhaps MartyO is familiar with some of this territory?

[TripleTransAm]

Hp is a function of RPM multiplied by torque. But look at force equations and they're all based on torque. Acceleration is a direct relation to force.

If the engine breathes very well up high, no problem - get it up there faster with gears, as was said. But at some point you're going to run out of top speed. And that'll hurt driveability... just ask any big block Chevelle owner that thinks the 5.xx gears and 4500 stall speed converter sitting behind his temperamental 502 big block is the $#it, ask him again after a cruise on the interstate.

Internal forces also increase as the square of RPM. Do you want to spin factory internals 3000 RPM beyond the factory designed RPM limit, because after all {sarcasm on} I'm sure they had extra cash lying around to devote to over-engineering the rotating assembly {sarcasm off}?

And then there's the other camp: look at the torque characteristics of the big Buicks of the early early 70s and look at the diff gear ratios used to get those performance results. Different approach.

Which one's more pleasant to drive? Which one lasts longer? Obviously I don't have the answer, but I invite everyone to give it some thought. Not all stoplight grand prixs are 1320 feet long.

[thePunisher]

Look at the Impalas timeslips page as far as their S/Ced ET's, and compare it with ours (that is when we get ours back again) and then comment.

If you're gonna say that having 4 valves per cylinder makes up for 20 or maybe even 30 cubic inches of displacement, I'll go along with that. But 70 cubes? No way. If that's what you think, then you haven't raced very many V8 cars with your Marauder other than other Marauders.

billy....not exactly saying that...but you could add more cubes to an engine all day....if the heads dont flow any air its like beating a dead horse...and in this particular comparison...the lt1s 70 cubes just dont do it....im sayin that 4 valves DO make up for 70 cubes in this particular comparison.....now throw the ls1 into the mix and now we have no comparison..same cubes but moves alot of air and makes good power..look at the big blocks of the late 70s...making 230hp...sure they were low compression...but they had 460 cubic inches....what good were those cubes then???? sorry if this is confusing...its hard to get my point across on the keyboard....:o

[BillyGman]

sorry if this is confusing...its hard to get my point across on the keyboard....:oNo, it isn't confusing. I think this is a pretty good debate. I understand your point. What you're saying is that more cubes is NOT a cure-all, and I agree. but what I'm saying, is that if you take two V8 engines, and start puting go-fast parts into them, as well as into the vehicles that they are in, the engine that has 70 more cubes is going to respond much better provided your modifications choicers are wise ones.

You stated that 70 more cubes won't do didley if there are lousey heads along with a lousy cam, and I agree, but by the same token, having 4 valves per cylinder is NOT a cure-all either, because if the engine in question is just too small, then the lack of displacement will NEVER yield the torque numbers that are needed to propel the car down the track like a bigger engine would. And all the valves in the world will NOT change that.

So my conclusion STILL is, that if you have two cars of similar weight, and with similar mods, and both engines are close as far as displacement goes (say within 20 cubic inches of eachother) but one of them has 32 valves, and the other 16 valves, then the 32 valve motor car will be faster with better ET's, but if the the 16 valve engine has a lot more displacement, then that 32 valve engined car is NOT going to walk right by. In fact, it may just be the other way around. And all the valves in the world will NOT make up for a 70 cubic inch displacement deficet alone. And from what I've read about this topic before on here, some people on here seem to think that having 4 valves per cylinder along with a DOHC design automaticaly means that the engine is superior to any otherwise sdimilar engine of the pushrod design, and that just is NOT true. if anyone thinks that, then they should take their own Marauder, and go race the Impala SS boys, and then come back and talk, because I have raced a number of them of all different modification levels with my Marauder. And it wasn't only four of them there at the track thar day like there was at the Marauderville event at Indy.

[Motorhead350]

wow I didn't expect my question to go this far. I still see those mid 90's Impalas as our rivals, but I think the Buick Grand National started it all as far as the rare, black, fast, Amercian cars goes. Then the Impala then us. I do not see GNs as rivals because they are totally different and don't even have V8's, but you gotta admit some of the Marauders influence came from that car.

[thePunisher]

i totally agree with you billy........ive onwned and modded both style engines and im still a fan of pushrod power.

[BillyGman]

On forced induction engines, the one with the rpm advantage will beat the one with more cubes and still be streetable. He just needs different gearing.

Not so with roots type superchargers. I have a roots supercharger on my Marauder along with 4.56 gears, and a 6,600 RPM rev limit and there wouldn't be any advantage at all to using a higher rev limit than that on my car. So many guys on here talk about taking the Marauder engine to 8,000 RPM's, and even 9,000 RPM's, but I've yet to hear of anyone puting their actions to that theory. It's so easy to say that you can get your engine to survive frequent 9,000 RPM blasts, but let me see you put that to practice. Something tells me that there won't be people lining up to take me up on that challenge. Talk is cheap I guess. And as far as the big block engine comparisant goes, the big block wouldn't need a high stall speed nor extreme gears in the rear to get the vehicle that it's in to move off the line, so that would make the big block car "more streetable" if anything. So I disagree with your post my friend. Maybe we best agree to disagree on this one, because it's like beating a dead horse.

I'm puting together a big block N/A pump gas car now as we speak(and I DO mean PUMP gas, as in 93 octane), and I'll let you know of the results soon since this is NOT going to be a long project.

[HAULNSS]

To revert back to the question of SC vs. SC, the LT1 isn't a great platform for supercharging. With the reverse flow cooling, they run 10.5 to 10.8 to 1 compression (depending on the source). If you start to add boost to that much compression, detonation rears it's ugly and destructive head. :depress: I think 4-6 psi is about the max for a stock LT1.

Carry on....

Randy

[Blackened300a]

To revert back to the question of SC vs. SC, the LT1 isn't a great platform for supercharging. With the reverse flow cooling, they run 10.5 to 10.8 to 1 compression (depending on the source). If you start to add boost to that much compression, detonation rears it's ugly and destructive head. :depress: I think 4-6 psi is about the max for a stock LT1.

Carry on....

Randy

Thanks for your Feedback and from your Sig I see you have a 6 speed Impala? How has that been holding up in a heavy car?? Some have tried to put a Manual in a Marauder and have had Transmissions not holding together because of the weight.

[Todd TCE]

And he's posting here~!

Gots my brakes on the front too. And the pedals came from me as well via Josh.

[HAULNSS]

And he's posting here~!

Gots my brakes on the front too. And the pedals came from me as well via Josh.


Actually Todd, I helped a friend do the Wilwoods on my car. I'm too broke to afford yours right now and he made me too good of an offer to pass up. Your kit has always been on my wish list, though! :coolman:

I was one of the first few to T56 an Impala with the BBHP kit. I'm #31. :cool:

The car has about 25k on the swap and has performed flawlessly at drag racing, autocross, and open track events. I beat the car like a rental every time it is out, too. If I can't break it, it is tough. :bows:

If you ever get the chance to ride or drive an Impala with a T56, do it. You will be grinning for days. :D

Randy

[BillyGman]

To revert back to the question of SC vs. SC, the LT1 isn't a great platform for supercharging. With the reverse flow cooling, they run 10.5 to 10.8 to 1 compression (depending on the source). If you start to add boost to that much compression, detonation rears it's ugly and destructive head. :depress: I think 4-6 psi is about the max for a stock LT1.

Carry on....

RandyThey also have a weak bottom end because of the flimsy connecting rods, but that hasn't anything to do with the LT1 being a pushrod engine, nor having merely 2 valves per cylinder as some here would have us believe.

[HAULNSS]

They also have a weak bottom end because of the flimsy connecting rods, but that hasn't anything to do with the LT1 being a pushrod engine, nor having merely 2 valves per cylinder as some here would have us believe.

I haven't really heard that the con rods were weak? :confused: I know many people have boosted or shot lots of N2o into a stock bottom end and they last very well. In many cases, the LT1 rods are an economical upgrade from a standard, earlier version SBC connecting rod.

From GM Performance Parts....
12495071 Connecting Rod Kit (5.70")
This kit includes 8 of P/N 10108688 high quality 5.70" length PM connecting rods which are used in the LT1 and LT4 Corvette engine in place of the old "pink rod" for higher strength and reliability. These rods can be used in competition or as street rods below 500 horsepower. Use P/N 10108688 for single rod replacement.


I work my car very, very hard and still have an all original engine with 173k miles on it. The connecting rods are the least of my worries. :D

Randy

[TripleTransAm]

I haven't really heard that the con rods were weak? :confused:

Haven't heard anything like that either. I know a few blown LT1s too, and no problems there with the bottom end (one of them in the 10s and fully streetable).

[BillyGman]

I remember reading an article somewhere that showed pics of the connecting rod beams as compared to ones from a vintage small block Chevy, and it stated that the beams are .060-.080" narrower, and that it's a source of weakness. i haven't heard good things about their cranks either.

To my knowledge there's already a lot more Marauder owners who are going supercharged with stock bottom ends successfully, than there ever were Impala SS owners. Perhaps the Impala guys you've heard about who have S/Ced their engines have also had to modify the bottom ends too, and didn't make it a point to mention that unless someone put them on the spot and questioned them on it. That happens a lot with car clubs. A number of guys mention only the positives about their modification costs, and they often leave out all of the details unless someone pins them down.

[David Morton]

Billy, you're right on about dollar for dollar comparisons, but I was talking theory about the technology. And yes, there's no replacement for displacement when there's money for equal rpm potential or when streetability is the main concern.

I'd love to see a 427 Cammer up close, and maybe someday a manufacturer will make a 12 cylinder with electrically operated valves that'll do 10,000 rpm. If pigs could fly...

What I was talking about is the fact that our heads are the best in racing technology available today in a production car. The Offenhauser formula one motors of years ago had what we have, 32v DOHCs, except the blocks and heads were one piece, actually there was no "head", and they could do 12,000 rpm! Grand Prix racing is the ultimate in streetability. And BTW, they did it with turbos, superchargers aren't the best thing for a high rpm engine. A supercharger is made for a motor with large displacement that doesn't like to wind. Actually the first blowers were designed to be used on GMC diesel trucks, redlined at 3500. The famous and venerable 6-71. Thank you Don Garlits & Co. for showing us what to do with a GMC 6-71 blower. Put it on a big block. 1000 hp on a stock 460 junkyard engine would probably be doable on our car, just cut a hole in the hood and move some stuff around. Might could do it for under $10,000. Very streetable, 9 seconds territory.

Then again I saw a 10,000 rpm 327 in a Nova back in the 80s advertising a grand in hp too. Sean Hyland will sell you a shortblock that ought to do 9000 for $5395. It's 1000 hp capable. (click here to see) (http://www.seanhylandmotorsport.com/gt-cobra-shortblocks.shtml)

I love talking about this stuff. :D

[BillyGman]

I love talking about this stuff. :DLOL...yeah, I can tell....so do I. Hey, weren't the first S/cers used in fighter planes in the early 40's???? I'm thinking of the P-38 Lightnings (although I'm not sure if they were S/Ced or turbo charged. One source says Turbo, and another says Supercharger. :confused:

[TripleTransAm]

Put that much money into out valvetrains and we'd be capable of 11,000 rpm.


One important aspect we've missed.

I was doing some reading this morning while eating breakfast (wife and kids were still asleep) and put together the following:

I saw a reference to F1 engines seeing mean piston speeds of somewhere just under 30 m/s. So let's choose 30 m/s to keep it at the top edge of the range. That's about 98.4 feet per second or 5900 feet per minute, which jives with the accepted quoted range of 5000 to 6000 feet per minute when using 'excellent' or 'exotic duty' quality connecting rods and pistons.

Most street engines see around 4000 tops in high performance applications, and I've seen a reference to GM's Indy racing V8 seeing 4350 mean feet per minute speeds. Most pedestrian engines like the 3000-4000 range as a ceiling.

If I recall previous threads on this board, our MM's connecting rods and pistons aren't exactly 'exotic-duty' quality. Good for street applications, but F1-quality? From a company resorting to removing remote fuel door releases and in-dash clocks, I think not.


So with our 4.6l engine's 90mm stroke, running 11000 RPM produces 6500 feet per minute speeds.


Take the same engine in a Mach 1 5-speed (7000 RPM limit?) and you get 4100 feet per minute... pushign your luck to 7500 RPM puts you at 4400 feet per second.


For reference, the early Honda S2000s (that revved to 9000 RPM) with their 84mm strokes saw just under 5000 feet per minute mean piston speeds! Sometime in 2002 or 2003 they addressed the complaints of low end performance by increasing the stroke to 90.7mm, but which also brought about a decrease in engine top speed to 8000 RPM. For these engines, they see close to 4800 feet per minute mean speeds.


No way we're going to see 11000 RPM without ventilating stuff...