Change one cam but not the other?

[LVMarauder]

I know cams give more power higher up in the rpm's and we need all the low end power we can get so what might be the result if you changed either the intake or exhaust but not both of the cams? might it be more power where we need it or is this just a pipe dream.:rasta:

[natedog1284]

That's a helluva good question. My brother's a mechanic and never heard of anyone trying that. I personally can say, that with my stage 2 cams, I have a lot more power in both high and low rpm's, (but especially high, it absolutely screams at around 5 to 6 grand :D ). It would be an interesting experiment anyway....Anyone else tried this?

-Nate

[salter]

That's a helluva good question. My brother's a mechanic and never heard of anyone trying that. I personally can say, that with my stage 2 cams, I have a lot more power in both high and low rpm's, (but especially high, it absolutely screams at around 5 to 6 grand :D ). It would be an interesting experiment anyway....Anyone else tried this?

-Nate

Nate tell me more about these stage two heads and cams, where'd you get em. what did you get outof em, what cost??

[Rider90]

I don't think this is a good idea.

[natedog1284]

Nate tell me more about these stage two heads and cams, where'd you get em. what did you get outof em, what cost??
I had them put on at my local speed shop. They are Ford racing heads with the matching valves and cams (here's a link: http://www.fordracingparts.com/parts/part_details.asp?PartKeyField= 5397). The mustang guys call them stage 2 cams. I bought them from the owner of the shop who had them shipped and built them for one of his regular customers, who apparently backed out of the deal, so he sold them to me for $2500. The idle doesn't sound much different, but it made a huge difference in power, and it seems to rev a little faster. I know full well any of the power adder guys will hand my a$$ to me, but I wanted to make it as fast as I could while keeping it NA, so when I do supercharge/turbo it, it will be quite potent :D. I haven't dynoed it yet, as funds are currently lagging behind my ever growing "I-want list", and I plan on doing a throttle body before then anyway. I plan to get it dynoed/tuned hopefully at the end of this month, so when I get some numbers, I'll be sure to post. I can't wait to see if they actually produce the 60 horses Ford says it does! I'll keep you updated!
-Nate

[SergntMac]

I don't think this is a good idea. It's rare that we agree, but we do now. Let's enjoy the moment?

If a full cam upgrade is 2400 bucks in parts, is half a cam upgrade 1200 bucks? And that's just parts, right again?

We already own "Cobra" heads, I too would like to hear more details on cam upgrades, porting and polishing, and so on...

If I can buy 50-60 FTlbs of torque under 4000 RPM, I'm in. If all I'm buying is 20-25 FTlbs, that's money better socked away and later spent on a blower.

The topic is open, let's hear more? I love discovering new things about this car.

My #1x isn't going to get any better, any faster. But, I have a bone stock #3 sitting here too, and a chance to do it all differently...

[merc406]

Do both the cams and blower, might be interesting.

[Rider90]

It's rare that we agree, but we do now. Let's enjoy the moment?
:banana: :beer: :cool: :P :burnout: :eek: :rasta: :lol: :banana2: :beer:

[natedog1284]

Do both the cams and blower, might be interesting.
That's the plan :D. Might upgrade to stage 3 or 4 too!

-Nate

[SergntMac]

:banana: :beer: :cool: :P :burnout: :eek: :rasta: :lol: :banana2: :beer: Means what?

[LVMarauder]

So does anyone actually know if its fessable. A couple people said bad idea but can anyone tell me why ( and for the sake of "we all already know its expensive" lets leave cost/ hp ratios out of it). I , like mac, just like thinking of different things to do to these cars.

[Todd]

It's rare that we agree, but we do now. Let's enjoy the moment?

If a full cam upgrade is 2400 bucks in parts, is half a cam upgrade 1200 bucks? And that's just parts, right again?

We already own "Cobra" heads, I too would like to hear more details on cam upgrades, porting and polishing, and so on...

If I can buy 50-60 FTlbs of torque under 4000 RPM, I'm in. If all I'm buying is 20-25 FTlbs, that's money better socked away and later spent on a blower.

The topic is open, let's hear more? I love discovering new things about this car.

My #1x isn't going to get any better, any faster. But, I have a bone stock #3 sitting here too, and a chance to do it all differently...


Mac, if you were mentioned the 'Cobra' heads in reference to Nates post above. those heads he mentioned are FR500 heads... They are not the cobra heads we have. They have a slightly modified intake tract. They make a good difference over the Cobra heads we all have.

[cyclone03]

Mac, if you were mentioned the 'Cobra' heads in reference to Nates post above. those heads he mentioned are FR500 heads... They are not the cobra heads we have. They have a slightly modified intake tract. They make a good difference over the Cobra heads we all have.


Jumping in here....
If he got FR500 heads and cams for $2400 thats a killer deal!

[natedog1284]

Jumping in here....
If he got FR500 heads and cams for $2400 thats a killer deal!
lol oh yeah, that's why I bought them 2 months before I had the money to install them! :o

[SergntMac]

Thanks for calling that to my attention, Todd, Nate posted his additional 411 while I was creating my post, and I didn't see his deeper explanation. Yep, he sure got a great deal, I would have taken it too.

Under normal circumstances, FR500 heads are 795. each, matching HP cam/valve kit, 1599. That's 3200 bucks in parts alone, for an approximate power gain of 60 HP, with shorty headers, and not including setup of the heads, install, and tuning.

Money-wise, those parts alone are 2/3 the cost of a supercharger kit that will deliver twice the performance.

IMHO, the numbers are not adding up...

Nate, you lucky dog! Can I hate you just a bit?

[Todd]

Thanks for calling that to my attention, Todd, Nate posted his additional 411 while I was creating my post, and I didn't see his deeper explanation. Yep, he sure got a great deal, I would have taken it too.

Under normal circumstances, FR500 heads are 795. each, matching HP cam/valve kit, 1599. That's 3200 bucks in parts alone, for an approximate power gain of 60 HP, with shorty headers, and not including setup of the heads, install, and tuning.

Money-wise, those parts alone are 2/3 the cost of a supercharger kit that will deliver twice the performance.

IMHO, the numbers are not adding up...

Nate, you lucky dog! Can I hate you just a bit?


I hate him to Mac...!!!!


I already had a call into a friend of mine who is a warehouse distributor for Ford Racing to get a price on those.... I still have the complete (cams, springs, valves, etc) Ford GT heads but I want a back up in case they cause hood clearance problems or something else unforseen.... Still havent got my price yet on the FR500's but I bet Nates price is still really great. I am jealous.

[StevenJ]

Custom cams and ported heads do require a retune right? If you get the custom cams and FR500 heads shouldn't you also get Paul's ported intake kit to go along with it? How much net hp gain do you think you'd get with that installed?

[LVMarauder]

So basically no one knows or cant offer an explination other than cost/hp or personal opinion as to why this wouldnt work. Guess ill look else where

[juno]

So basically no one knows or cant offer an explination other than cost/hp or personal opinion as to why this wouldnt work. Guess ill look else where

There may be more real world info on the 4v mustang sites. let us know what you find!

[SergntMac]

Custom cams and ported heads do require a retune right? If you get the custom cams and FR500 heads shouldn't you also get Paul's ported intake kit to go along with it? How much net hp gain do you think you'd get with that installed? Yes, and I would expect a serious "start from scratch" kind of tune to really pull the power out of the head and cam mods.

That's a good suggestion on the PHP extrude honed upper and lower intakes, Steven, thanks. But, it's another 1200 bucks (w/core charge, 2400.) too. I don't recall the performance stats of this mod alone at this moment, but let's give it another 60 RWHP just for this discussion. You're now at 120 RWHP, and over 4700 bucks in parts alone. There's still setup, install and tuning, and for sure with the PHP intakes, that a 1000. tune. Remember, dyno tuning sells by the hour.

Gentlemen...This is brainstorming is "old school" engine building, and we haven't touched the stock short block yet. How do y'all think the bottom end is going to hold up under all this new breathing?

Seems to me it's a lot of work (and cash) spent, when viable alternatives for building power from a 281 CID engine are available on the market. I could toss a base Roots, or, centrifugal air to air supercharger kit on a bone stock MM (if there are any left in the world) and still beat your pants off at the stop light. the only thing that's shaping up here, is a an old school bracket car, where no matter what you do out of the gates, you won't break out.

So basically no one knows or cant offer an explination other than cost/hp or personal opinion as to why this wouldnt work. Guess ill look else where Dude, I've been telling you why it's not a good idea. This doesn't mean it's a bad idea, just an idea that's a formula for a specific style of engine that's good for bracket racing.

You seem pizzed that the flow of 411 didn't go tyour way and I'm sorry about that, but maybe it's the truth. This is a 4400 pound car with a 281 CID engine...There is only so much you can do, without serious risk to (or investment in) the rest of the car. For most of us, it's still a family/travel car too, and that figures into all answers.

You never said which cam you want to switch out. Intake or exhaust? And if so, do you have anything in mind?

Crower has a nice 4 cam kit for the Cobra...2400 bucks...What is it you want to improve?

I don't mind brainstorming new ideas, or, even getting into them. But, you have to deal with the reality of the Marauder too. The stock cams and heads are pretty fu*king good already. "If it's not broke, don't fix it" works for me.

OTOH...Makes me wonder what happened at the last moment that made L/M change their minds on a supercharged 2V...

[LVMarauder]

Im not mad at all Mac , glad in fact, so im not sure what you are talking about there. No one gave me a tech explination of why its a go or no go and honestly man I asked at the begining to leave HP/cost ratios out of it.

I never said which cam I would switch out becuase that is what i have been asking, which cam? how hot a profile? Tuning adjustments? Thats what i want to know.

edit: I forgot to add If i want to go fast ill hit the 100 shot , so I guess I just want a little more NA gettyup.

[MikesMerc]

I'll only go on record saying this- bang for the buck, cam swaps are very very low on the mod list for 4v mod motors. Ask most of the competent tuners (Lidio and his peers heavy in the mod motor scene) and they will tell you the same thing. The issue is that the 4v head/cam design leaves little untapped potential on the table. This is why you have many many 9 and 10 second 4v mustangs that run stock cams and maybe, just maybe, some mild bowl work on the heads. Hogging the runners out doesn't help at all. These 4v heads breath very well from the factory....unlike most of the old school pushrod motor heads. sure, cam swaps CAN help. But this is something usually done near the bottm of the list after all cheaper ($ per hp gained) power upgardes have been tapped.

Just my 2 cents.

[Joe Walsh]

I'd have to agree with what has been said about Cams for our DOHC engines.
I wouldn't bother UNLESS I was changing the heads as part of a complete forged engine rebuild.

Otherwise, I'd just bolt a blower on the OEM engine.

FWIW: When I was rebuilding my engine, I had my OEM heads re-done with a mild bowl cleanup and +1mm sized SS valves installed.
Then I put in a set of Crower Cams ($900/set then...now $1200+/set).
The Crower Cams are the 'Baja Beast' Cams that have a little more duration and some extra lift vs OEM Cams.
I did NOT want to sacrifice torque in a 4400 Lb sedan with an automatic.
I also had my intake manifold Extrude honed for $700.00, then port matched the head's intake ports to the enlarged lower intake ports.
I did NOT dyno test these items seperately from the forged big bore engine rebuild, so I can not attest to the Cam/Head horsepower gains.
I would say that +60HP is optimistic for a Cam/FR500 head swap.
As has already been said: Our OEM MM DOHC heads are pretty darn good.

[natedog1284]

Nate, you lucky dog! Can I hate you just a bit?

I hate him to Mac...!!!!

Awww....feel the love....:grouphug:


Custom cams and ported heads do require a retune right?...

To get the most power: absolutely. However, my car is still running an off the shelf SCT tune, and it runs awesome. I imagine that a ported intake/ throttle body combo would make the afforementioned mods even better, but since I plan to do some kind of forced induction next year, I'm not gonna bother with the intake, (if I do the Trilogy kit, there's no point); plus.... I don't have much money left :o ; so I'm just gonna be doing the throttle body and a tune. But since there seems to be some interest in my power gains, and simultaneously an interest in the hp value of throttle bodies, I suppose I can get my car dynoed before I put on the TB/have it tuned, and then again after, (obviously) so I can hopefully satisfy everyone....the things I'll do for you guys :rolleyes:. I'll call tomorrow and set up an initial appointment, and when I get some firm numbers, I'll report back.
-Nate

[natedog1284]

....How do y'all think the bottom end is going to hold up under all this new breathing?....
Very true Mac, and I will be addressing that issue down the road; I'm sure some things will need to change....(forged stroker shortblock anyone?)
I'm trying to cover as many bases as possible as far as power gains. Hopefully others can use what I've found as far as hp/cost ratios to decide which route they want to take, and I'm sure I'll be able to use this information for myself again down the road. I'm trying to either bust or confirm as many myths and rumors as I can. This is another reason for me to want a twin-turbo setup....as if I needed another reason anyway :rolleyes:.
Anyway, stay tuned everyone, I'll get you some more info as soon as I can, and btw, thanks for the interest (I love the lime light!!! :D)
-Nate

[AzMarauder]

So basically no one knows or cant offer an explination other than cost/hp or personal opinion as to why this wouldnt work. Guess ill look else where

I think what you have found is that no one has tried it yet.

My opinion.. it wouldn't work. The cams are designed to have specific overlap between exhaust and intake port openings. If you change just one 1/2 of that equation.. who knows what you will end up with.

Having said that.. if you had the two cams sitting there... I am sure a highspeed mechanic could check the specs etc. and determine what you would be doing to the motor. But personally, I wouldn't go near such an idea.

Go with cams that are meant to run together.

[Rider90]

Keep us posted on the results if you choose to do this. Thanks

[cyclone03]

I think what you have found is that no one has tried it yet.

My opinion.. it wouldn't work. The cams are designed to have specific overlap between exhaust and intake port openings. If you change just one 1/2 of that equation.. who knows what you will end up with.

Having said that.. if you had the two cams sitting there... I am sure a highspeed mechanic could check the specs etc. and determine what you would be doing to the motor. But personally, I wouldn't go near such an idea.

Go with cams that are meant to run together.


One tuning option open on DOHC engines is that the intake/exhaust overlap can be changed by moving one or both cams.By moving the lobe seperation angle(LSA) power can be moved higher or lower in the engines RPM range.

But this takes time and Dyno runs to work out,and I garaunty nobody is going to give you those specs for free!

Given our stock 6200rpm limit you may be able to run a bigger cam(lift and duration) then open up the LSA to get the torque and HP peak down below 6200 but how much power and what LSA,and cams,to pull that off only your engine builder and cam grinder would know for sure.

Now go to a stick shift Mustang with a 7200 limit and your options grow because the R&D is done and the knowlage base is growing on those combinations, 400hp N/A Mach 1's are on the streets.But that 400hp is at 6800+rpm and the torque peak moved to 5000!

If a cam or cam/head swap could give 60hp and keep the HP and Torque peaks within 200rpm of our stock 4200/6200 then you would have something.

In N/A trim just adding 60lb/ft of torque would change how our cars run, and sold new, by 75-100%!This board would have 10,000 members and Ford would have sold less Mustangs!
But Ford couldn't find 60lb/ft in 281cid.
It would be great if sombody could but I don't think it will happen at 281cid.