Ok, the long awaited 383 build is about to commence... And i need some combination advice. Heres what i have and am trying to incorporate into the motor:

First off, the goal with this motor is simple, im building it for between 450-500 hp, N/A. My main focus is not on power, its on reliability and safety. Id rather run 450hp consistantly, than 600hp once and blow the motor after 3 runs. With that being said, please help. My budget isnt terrible, im looking to drop about 1600 on the rotating assembly, and just as much on heads, if i can get it for less money than that, even better.

L31 Roller block Bored .30 over with 4 bolt splayed main caps. (i know, splayed are probably overkill with my expectations, but better safe than sorry is my idea here._

Edelbrock preformer intake manifold

Edelbrock 650 CFM Carb

Cam, no clue what it is, ill get back to you guys with details on it, but odds are id rather buy a cam thats tailored to my wants.

The rest i get to buy....

Heres what my MUST HAVES ARE.

The rotating assembly MUST be forged. Im looking at the SCAT rotating assemblys with the forged 4340 Crank, forged rods, and forged pistons. Im uncertain as to what pistons i want to run, initially the motor will be N/A, but the goal is to add nitrous up to a 150lb shot (MAX) or a supercharger. Any advice on pistons, im leaning towards dished pistons for the lower compression ratio, but im open to all suggestions.

For heads im leaning towards AFR's 195cc heads with 75cc ports, once again for lower compression ratio. But im concerned with the fact that they are aluminum, i also have noticed that summit has a great deal with their "top end" kits, which they run with Dart Iron eagles, once again, im lost here, i know AFR's are amazing, but id feel safer with Cast heads.

As far as cam, am i best off calling somebody at say, comp cams, giving them my specs, and letting them do the work for me? Im not wanting something too wild on the cam side, this car will be driven on the streets as well as track.

Thanks for the help guys,

joe

 

You'll change your mind about splayed caps once you find out how much it's going to cost.

The Performer RPM intake would be better than the Performer.

Choose nearly any other carb besides an Edelbrock 650.

What's your concern with aluminum heads?

 

I found that the 600cc Holley 4150 on the Edelbrock performer RPM manifold, mild cam with 1.6 ratio rockers to be a good performing, reliable setup on a lower compression engine. You might look at Comp Cams nitrous setups and choose an intake to match their cam. I also favor ID HEI over CD ignitions such as msd for their longer spark durations. CD systems only spark once at higher RPMs anyway. Make sure you have a good fuel delivery setup. I like an electronic pump near the tank with a mechanical in its normal location, large lines and a regulator.

 

Ive already had the splayed caps put on, i know the cost, and to me it was well worth the peace of mind and possibilities for future expansion. I feared the worst with the edelbrock 650, the only reason i considered keeping it is that it is matched with the intake, and that i already have it.... My worry with Aluminum heads is overheating, which ive been led to fear can cause warping. If my concerns are invalid with the aluminum heads, then id much rather run a set of AFR 195 street eliminators,
a Edelbrock #7101 Performer Intake, an AED 750 Holley, my last concern is the cam, And i see the AFR guys used the a comp cams cam with a 236/242 int/exh duration at .50 lift in their DYNO page, now from what i know this would fall into the "mild cam" catagory, which i tend to associate with it bneing a safer cam, however im a bit drawn to their "thumper" series (235/249 int/exh duration at .50 lift) due mainly to the rougher idle, but im concerned this is more of an aggressive cam, which would i be safer running the first cam i described, or is it really not a big deal? Aside from that, is my choice of pistons mainly important based on the compression ratio i wish to achieve?

 

I'd stay away from the thumpr line as it would be all bark and no bite. I would also stay away from scat and eagle, after see'ing 3 scats and 2 eagle cranks at my machine shop sitting in 3 peices. Check into the lunati, crower, winberg, or ohio crankshafts. I am running the AFR 195 eliminator's on mine with the 75cc chambers, SRP/JE pistons would be the way to go especially if you plan to put the juice to it. I also went with a 5.7" rod because after looking at the 6"ers it put the oil control ring right on top of the wrist pin on the pistons.

I am uncertain why you would want the cast iron heads apposed to the AFR's. They are about the same price and the aluminum will disperse heat better, better flow #'s, lighter ls1 style valves...etc

Has the block been zero decked? you will need to figure out the compression height on the piston that you will need. Before determining the compression ratio you will have to make a decision on the heads that you want to run.

+1 for ditching the edelbrock carb, go grab yourself a 750 double pumper!

 

Don't put any stock at all into the marketing hype that it's "matched" to anything. it's about as matched as any other squarebore carb.

Overheating warps iron heads, too... but you're not going to let it overheat anyway, right?

 

Thanks... its final, AFR heads it is. And after seeing the numbers made with the intake you reccomended... i think scrapping the carb and intake and moving on up to a Holley 750 with a Preformer RPM intake. My last question is going to be pistons... assuming the following information: 4.030 Bore Size, 3.75 stroke, 4.03 head gasket diameter, .039 head gasket thickness(compressed), 75CC combustion chambers, and the piston being .014 inches in the hole before counting the gasket, i get an estimated compression ratio of 10.1 with flat top pistons, and 9.07 using -11 dished pistons. The car will need to run off of at least 93 octane, and eventually will be run with a supercharger on the same 93 octane. Based off the knowledge that I am using a Supercharger and will need a relativly low compression ratio before and forced induction, is a 9.1 a safe compression ratio? or do i need to aim lower? Or higher?

 

Popular wisdom says i'll make more power with lower static compression and higher boost than you will from higher compression and less boost.

 

Might want to check out Competition Products for your rotating assembly...They sell some quality cranks and rods... I've used the Howard's products they sell and have been very pleased with the results!!!! The quality is definitely higher then the import stuff!!!!! Over 300 passes (about 100 per season) in the drag car engine and still not a sign of anything other then normal wear on the bottom end at this winter's tear down!!!!

PS--this is a Super Gas car, btw...

 

Not all that mild by any means, that cam will peak 6300-6400 rpm on a 110 lsa. Its streetable enough tho but not all that mild, as mild would be like a 224/230 or even a 230/236 cam. XE grinds have fairly aggressive lobes so with AFR heads get their upgraded 8019 springs. Its necessary to control those springs at those rpms.

Thumpers arent bad cams. I ran a 230/245 on a 109 in my car and it was very streetable, peaked at 6300 holding peak to 6500+ and i shifted 6600-6800. Dyno'd 400 at the tire and ran mid 11's without trying to hard. Idle will be very choppy and aggressive but overall its not all that bad of a cam. They will sound abit more aggressive than they really are which is the point of that grind.

Nitrous will want flat tops for 11 to 1 with 65cc heads, supercharger dished for no more than 9.5 to 1 with 10-15 psi on pump gas.

 

great info guys, the no more than 9.5:1, is that with the 10-12 pounds of boost or before? Whats a good formula for estimating what lets say each pound of boost will do to my compression ratio? Based off of that info, is shooting as low as possible the best idea for Compression Ratio? So 75cc exhaust ports with the -11 dished pistons would be wise, putting my compression ratio at roughly between 9:1 or 9.1:1? With these numbers whats the safest amount of boost i could run off of the 93 octane? Thanks so much for all of the advice and help. You guy are life savers.

 

I'm not sure of the final compression ratio after boost is added, but 9.5 to 1 will handle 10-12 psi just fine with aluminum AFRs. I'm at 9.0 to 1 with 93 oct gas and i've touched over 18psi with no problems but I only run 14psi at the track and on the street. I will push that this year hopefully.

 

Static compression doesn't change.