I am going to build a motor for FI here shortly.My question to all of you is would it be beneficial to build a large displacement motor like a 408 or 422, or build something in the 346-382 range? I know the whole thing of bigger is better but does it neccessarily apply to FI? My opinion of it is if I am going to be able to spin the motor to 7k+ with a larger stroker, what would be the point in building a smaller one because with more displacement there is more potential to build power correct? I would just like to hear some of your opinions and what route you chose and if you think that it was the right choice.

 

I have a 422 Iron Block. If I had it to do again, because of the cooling issues with the iron block retaining more heat and the extra weight, for my horsepower goals, I'd use the aluminum block and make a 382 or 383.

You lose ET because of weight and you lose hp because of higher temps. Plus you will spend more money on higher capacity cooling fan and larger radiator.

 

Ouch! Glad I kept my baby 346.
Sorry, couldn't resist.

 

DO u think that a 408 will get as hot as a 422, because the cylinder wall is thicker....But I was planning on upgrading the cooling capacity of the car anyways.The car will be down for at least 1 year so I can do the project and make sure everything is up to what I am gonna throw at it.So far I have priced out almost evrything and for this project to be complete I am looking in the range of 40k+.....

 

What about a C5R. There was a gold WS6 442 C.I.D. C5R at the TA Nats. that ran 9.4x@150. All nitrous, but I'll bet it would be impressive with F.I. also. Look at Lingenfelter.

 

Well,you are realistic on the cost of the project.As a former iron block owner I would pass on the heavy block.If I was doing a FI project it would be a factory bore with a stroker crank and all forged internals.You don't need huge cubes to make power with a turbo or SC.Look at Rob Raymer,Scott WS6,Y2K Hawk and PSJ's current project.They're the fastest FI guys out their and all using factory cubes.

 

Well a C5R block cost like $5k for just the block??
engines typically run up around the $30k when finished

That one guy with the 442 C5R kics butt, lot of work into that care by ARE.

anyway cubes will help you
i wouldnt what to weight into it so id stay alum. but a 382 stroker or a 422 bore and stroker would be nice.

 

I would still stroke the aluminum block. Bigger cubes will give you more torque. Your torque numbers will DEFINITELY benefit with a supercharger... it will have that top-end, high RPM pull like a centrifugal SC gives, yet have the low-end grunt that a motor on Turbo would have.

Of COURSE the C5R would be a best bet... I'd definitely go as big cubes as possible, then. But, it is SO costly.

 

I am actually going the turbo route.So the general concensus is bigger cubes but with the aluminum block? I was going to get a 6.0 block just because of structural reasons.I am going to be running a lot of boost on this motor and I want to make sure that the integrity of the block is not going to be an issue of failure.

 

What you just stated makes me realize we never really asked the REAL question: what are your GOALS for this car? How much RWHP / TORQUE? How quick/fast? Streetable balanced with strip, or leaning one way or the other? We know your budget.

 

Well I would like to go as fast as 40k+ would let me go.I am seriously looking into low 9's high 8's.800-900rwhp.Mostly track use but some street driving to pay some bills.

 

To give a basic breakdown of the motor I am going to build it will consist of A sheetmetal intake,Lunati pro billet rods, pro crank, shaft mounted rockers,oversized studs for mains and heads, stage 3 LQ9 heads,7.5-8/1 compression,Hydra rev kit,Qmp turbo kit with a PTE T88 turbo, and all the other good stuff to go along with it.I was planning on running a 408 iron block,but I wanted to see what everyone else thought of the idea before I went through with it though.And the only other thing I have not decided on is the cam.

 

If you can go big cubes in a C5R Block, I would. I personally do not believe the stock aluminum block will handle 700 or more RWHP over the long haul (based on discussions with builders). My choice would be the C5R as a 427 CID.

With the power you are going to build (even though it DOES make a difference with even 75 lbs of extra weight up front), if you can't afford the C5R block, I'd get the Iron Block. Just get the largest radiator and fans you can. Since you won't have the problem I have with the D-1SC in the way of a second fan, get a dual fan unit pulling as much CFM as possible. Then, you should have no cooling issues. Are you reneging on the 422 and going to 408 for extra cylinder wall thickness? Just curious. The Iron Block should handle up to 422 fine, without sleeving.

And definitely do turbo... you can't afford to be wrestling with belt/pulley issues with that kind of boost and power.

The biggest cam you can get in there is what I would do, with a wide LSA. The cubes is going to swallow up the cam, so, since you are mostly racing this thing, go as radical as possible. Just make sure the grind is a Turbo profile.

I didn't see what kind of tranny and rearend you are going to run. Most drivetrains will need considerable beefing up to handle 800~900 RWHP!

Also, weight reduction, max suspension work and the right rubber is going to help you achieve your ET goals.

With that power, and big cubes, FAST is the only setup I can thing would manage your fuel... and you are going to need gobs of it.

With all you need to do just to SUPPORT 800+ RWHP, a considerable portion of your budget is going to get munched on, so calculate those costs carefully before settling on an expensive block.

Good luck, man! It should be exciting to see your car get built. Keep us informed!

 

I was originally planning on running a 408, for a little extra thickness and slightly shorter stroke,but if there would be an extra incentive to do a 422 I would do so, but I think I am actually going to stick with the original plan of doing the 408.

 

I say go with the 408 iron block. I know people running it and have NO heating issues (temp stays around 190.) BTW if you are making 800rwhp I hope you don't have a stock cooling system (LS1 radiators are junk.) If the Iron block is so bad for cooling why aren't the 2500 Chevy trucks having problems? A .030 (408) over bore is nothing but when you are .060 over (422) there is going to be a diffence in engine temp. Look at it from a structual stand point. I say Iron block. You can take out that 100lbs with AC/K-member. With skinnes and other weight reduction mods you will be lighter then you were before.

 

Actually when its all said and done I think the car will weigh almost as much as it did stock.The k-member they say is good for 36 lbs, but how much will the turbo kit, intercooler,and all the piping weigh? Not to mention a rollcage and all the required saftey equipment. I think the 3/4ton trucks don't have a problem with cooling because they use a 3 core radiator in the first place with more of a surface area to help in cooling.But I am going to go with an iron block simply because if the motor at any point decides that it doesn't want to keep the rods inside its easier to replace a 600dollar block vs a 6000dollar C5R block. It would be really nice to have one, but at this point I see it as too big of an expense for the purpose.Beside if weight was that big of a problem I'll go on a diet myself.

 

I am saying with a larger radiator. BTW I have my 408 MTI short block on order . Good luck with everything. FYI 6 point wolfe race craft mild steel cage weights about 85lbs. Just to give you an idea. You will need a 10 point so that will be around 105-115lbs is my guess.

 

What amount of boost do all yyou guys think I will be able to run with this setup?

 

I think you could at least run 2 lb. It would be close with that much hp. though. I had to at least put something in greg. Over all though it should be a sweet setup.

 

Even at 2psi it would be enough to take your truck with your 300 shot.