Big power on built mark viii block?

[minimarine09]

Ok, I have a couple questions,

so I've done a bunch of research and I'm hearing allot of contradicting information. I'm new to the modular game so bare with me. I'm planning on purchasing a Lincoln mark viii block and throwing some Forged rods/ pistons in it . Goal would be 700whp +

From what I gather, the major plus is the teksid block. The cast crank doesn't seem like it would be up to my power goal task (am I wrong?) , so I was thinking a cobra crank would suffice.( Would that just be a drop in ordeal?)

After machining the block, assembly, etc... Would our heads just bolt right on? Oil Galleys/ coolant passages all line up? / motor mount differences? Oil pan clearance issues? Transmission mounting issues?

I'm probably forgetting some questions, but looking forward to hearing from you guys! Thanks! :beer:

[minimarine09]

I'm currently running a D1sc Procharger, if you are wondering

[FordNut]

Stock block and crank will be ok. Teksid will work also. Weaknesses are stock rods and pistons in both.
I loved the power from the D1SC.

[minimarine09]

Stock block and crank will be ok. Teksid will work also. Weaknesses are stock rods and pistons in both.
I loved the power from the D1SC.

Nice! My plans are to build a motor on the side, so might as well get a mark xiii short block. would everything be a straight up bolt on affair? (with my current heads, motor mounts, etc...) Or would I have to change anything? You don't think 700-800hp would be pushing it for the cast crank?

[Mr. Man]

Good read about the blocks

http://www.mre-books.com/sa82/sa82_1.html

[FordNut]

Nice! My plans are to build a motor on the side, so might as well get a mark xiii short block. would everything be a straight up bolt on affair? (with my current heads, motor mounts, etc...) Or would I have to change anything? You don't think 700-800hp would be pushing it for the cast crank?

There are minor differences. Knock sensor mounting, early vs late crank trigger ring, maybe the cam chain tensioners and pivot pins.

I think a forged crank will have the 8 bolt flywheel so you would need to find a flex plate. If you can find a forged crank cheap it won't hurt anything, but the cast crank will be ok too.

[MOTOWN]

I would not attempt to push a cast crank past 600 at the wheels, 700 rwhp on a cast crank will be on borrowed time.

[minimarine09]

There are minor differences. Knock sensor mounting, early vs late crank trigger ring, maybe the cam chain tensioners and pivot pins.

I think a forged crank will have the 8 bolt flywheel so you would need to find a flex plate. If you can find a forged crank cheap it won't hurt anything, but the cast crank will be ok too.

So besides the flywheel /flex plate, any connectors would be the same, no issues with crank position sensing since differences in the trigger plate?


I would not attempt to push a cast crank past 600 at the wheels, 700 rwhp on a cast crank will be on borrowed time.


^^^ that's what I mean, contradicting, I hear that the crank would be fine, then I hear that it may explode. Is there any proof to either side?

[Bradley G]

i understood the threshold for the OEM cast crank is @600 RWHP.
I had the car down three years til I got it back together.
all I can say is trust no one here !

[Bradley G]

i understood the threshold for the OEM cast crank is @600 RWHP.
I had the car down three years til I got it back together.
all I can say is trust no one here !
If I had it to do over , I could have bought brand new instead of dragging my ass all over to get misrepresented garbage.

[SGT_MERC]

The biggest problem with a cast crank, in my opinion, is the flex on the snout you'll have with driving the supercharger. Even with the forged crank, some guys, like myself, will stay with the caged lower pulley. I'm not sure how the belt/belts run with a centri. I'm sure there are other weak points with a cast crank, but the flex on the crank snout is the one I read about the most from the cobra guys, when having crank failures, when going with a bigger roots style blower

[minimarine09]

What about the heads? I was reading the b heads are better for boost while our heads ( c heads) are better for low end / mid range n/a. Any input on that?

[minimarine09]

Ok so block wise, I've pretty much made up my mind, I'll go with a teksid block, cobra crank, eagle rods, and around 10:1 Cp, diamond, Wiseco, ect. Pistons. With arp head and main studs I figure the bottom end will be bullet proof.

[F1erceK]

It will work fine. Skip the knock sensor its a waste of time. I obsessed over it for a short period, glad I didn't let it cost me any money. One of the motor mount locations will need some aluminum removed in order for one of the mounts to bolt on properly, I don't recall which side. You can use either the marauder crank gears and timing sensor sprocket, or the set from the mark8, you cannot mix them - you will see why when compared. Feel free to PM me if you need.

[Chayton]

So besides the flywheel /flex plate, any connectors would be the same, no issues with crank position sensing since differences in the trigger plate?




^^^ that's what I mean, contradicting, I hear that the crank would be fine, then I hear that it may explode. Is there any proof to either side?

put it like this.... I have a forged, 8 bolt crank in my NA marauder. So theres no reason why you shouldnt have one either.

[F1erceK]

put it like this.... I have a forged, 8 bolt crank in my NA marauder. So theres no reason why you shouldnt have one either.

This ^

When I built mine I built with the idea of sustaining 700+whp, I like to think I succeeded. I knew boost could happen, but you never know in life so my built motor started out NA. Build your bottom end for your end-game goal, otherwise it will cost a lot more over time. Make sure you gap your rings accordingly! .016-.020 is for NA, not for 700whp. I believe .025-.028 is what you want for those numbers, but your builder should know. If he says NA ring gap is fine for big power, he's wrong.

[minimarine09]

It will work fine. Skip the knock sensor its a waste of time. I obsessed over it for a short period, glad I didn't let it cost me any money. One of the motor mount locations will need some aluminum removed in order for one of the mounts to bolt on properly, I don't recall which side. You can use either the marauder crank gears and timing sensor sprocket, or the set from the mark8, you cannot mix them - you will see why when compared. Feel free to PM me if you need.

Any particular reason why people are ditching knock sensors?


put it like this.... I have a forged, 8 bolt crank in my NA marauder. So theres no reason why you shouldnt have one either.

Lol n/a? But why though lol how high are you revving?

[Chayton]

Any particular reason why people are ditching knock sensors?



Lol n/a? But why though lol how high are you revving?

over 9 thousand

[Turbov6Bryan]

over 9 thousand

But when vtec kicks in, it's the second 100 horse!

[Guittard22]

I would not attempt to push a cast crank past 600 at the wheels, 700 rwhp on a cast crank will be on borrowed time.


How about 617 hp lol

[FordNut]

Keep in mind what the ultimate goal is. A street car or a track car. High compression and boost could put you in a race gas only situation. It's not readily available in my neighborhood.

[loud2004marquis]

Any insight to the limits of 93 octane?

[Mr. Man]

Any insight to the limits of 93 octane?
Read this. It won't specifically answer your question, but it will give you some incite to your question. :)

http://www.badasscars.com/index.cfm/page/ptype=product/product_id=391/category_id=13/mode=prod/prd391.htm

[SGT_MERC]

Great article...

[minimarine09]

Keep in mind what the ultimate goal is. A street car or a track car. High compression and boost could put you in a race gas only situation. It's not readily available in my neighborhood.

If I can't do it with 93 and a bunch of meth, then I'll do it with e85. Gotta love that corn juice

[minimarine09]

This ^

When I built mine I built with the idea of sustaining 700+whp, I like to think I succeeded. I knew boost could happen, but you never know in life so my built motor started out NA. Build your bottom end for your end-game goal, otherwise it will cost a lot more over time. Make sure you gap your rings accordingly! .016-.020 is for NA, not for 700whp. I believe .025-.028 is what you want for those numbers, but your builder should know. If he says NA ring gap is fine for big power, he's wrong.

I build my own motors, normally for ring gap I'll just consult the piston manufacturer if the provided spec card they provide is questionable

[loud2004marquis]

^^^interesting read^^^ makes me wonder what the typical drawbacks of our oem engine's design are. Have heard lots of comments over the years of the rotating assembly being a weak point. Article mentioned many more variables to consider...what other variables are there to consider that people have addressed in building our oem engine for boost on 93? Would be nice to keep our lighter weight aluminum block as compared to an iron block.

[FordNut]

Any particular reason why people are ditching knock sensors?


Some tuners turn them off anyway, so they don't need to be installed.

Mine is installed and turned on in the tune, the sensitivity is turned down so false knock doesn't trigger the tune to pull timing.

Forged pistons and loose clearances needed for supercharged engines creates some noise, especially on cold starts.

[Zack]

I build my own motors, normally for ring gap I'll just consult the piston manufacturer if the provided spec card they provide is questionable

Any boosted car should have a second ring gap at .024, Not what the mfg suggests

[minimarine09]

Any boosted car should have a second ring gap at .024, Not what the mfg suggests

um, i believe the different expanding rates, at different temperatures, at different power levels, with different materials, that different manufactures use, may vary the ring gap on different setups... id rather trust an aftermarket piston company that has spent years and MILLIONS of dollars on r&d. just my .02 though.

[Zack]

Then research boosted cars locking the 2nd ring on high hp applications. LSx engines go all the way to .030. But what do I know


Sent from my iPhone using Tapatalk

[MOTOWN]

There is no set ring gap spec on a Blown Modular motor , it depends on what type of rings are used be it stainless , moly , or cast rings , and also what type of piston forged , hyper , or cast , and compression ratios also play a role as well.

[massacre]

What about the heads? I was reading the b heads are better for boost while our heads ( c heads) are better for low end / mid range n/a. Any input on that?

Unless you are John Mihovetz B heads are basically useless. C heads are a much better design for 99.9% of applications, especially for anything that is street driven.

[minimarine09]

There is no set ring gap spec on a Blown Modular motor , it depends on what type of rings are used be it stainless , moly , or cast rings , and also what type of piston forged , hyper , or cast , and compression ratios also play a role as well.

This^^^^^


Unless you are John Mihovetz B heads are basically useless. C heads are a much better design for 99.9% of applications, especially for anything that is street driven.
Thanks I figured, after seeing how cheap they sell for! Lol

[RubberCtyRauder]

Dont forget if you are planning a 700+ motor, you are going to need a better trans. stock wont last, and while at it, should upgrade axles.

[FordNut]

Dont forget if you are planning a 700+ motor, you are going to need a better trans. stock wont last, and while at it, should upgrade axles.

I sure wish we could get a bolt-in 9" rear end.

[MOTOWN]

I sure wish we could get a bolt-in 9" rear end.

Its really not that difficult to Fab/mod one to fit the Marauder , mines will be in this summer:banana:

[RubberCtyRauder]

member Lifespeed has one in the works ( 9" ford)

[minimarine09]

The 8.8 can take ALOT of abuse, I don't see a need for a 9 inch , but I guess even 9 inches break in certain conditions.

[lifespeed]

The 8.8 can take ALOT of abuse, I don't see a need for a 9 inch , but I guess even 9 inches break in certain conditions.

The worst part about the 8.8 is the awful bearings and c-clip axles.