tpi 421 vette

Hey Guys, I am building a 396 for Cumbercr (Craig Cumberland). It will have a Super Ram and AFR 195 heads. 11.1 compression, a Crower 221/230 .560 .586 on a 114 lobe sep cam. SRP forged pistons, Crower stroker sportsman rods w/7/16" bolts, and a Eagle 4340 crank. I have it built to a shortblock. I degreed the cam today, and the cam timing is perfect. That also gave me a chance to adjust the timing pointer to true absolute TDC. We are still waiting for the heads, but they should be here in the next few weeks. This is an emission legal engine that should make excellant power, pass emissions, and still pull down some great gas mileage.

Here are some pic's. I will update it as it progresses.

383vett

Sweet Jim. Looks great! I'm sure it'll be a stout motor. Willie

pr0zac

i see you used an eagle crank. i know the cast ones have a bad rep for their tapered journals. was this one good to go or did it need some touching up? not stirring up ****. i have the same crank in my car. its just about 10 years old. this sounds very similar to pwnages build. he has a scat crank and rods and a comp 08-467-8 cam and some darts heads. would like to see how they differ in the end. anyways, looking good!

cumbercr

This one checked out good. The machine shop did a little polishing on the journals but nothing was required. I think the key with any components is to trust but verify.

pr0zac

i agree and i know that jim will make it perfect for you, i was just curious.

tpi 421 vette

The machine shop checked the index, and mic'ed it very carefully, and everything checked out good. But it did need to be polished better, so we polished it. I think if everything checks out good with Eagle or Scat 4340 cranks, they are pretty bulletproof, especially for the price. You don't see 4340 cranks break very often, unless something causes it. And for Craig's 396, a 4340 crank is bulletproof. This engine probably won't see over 6000rpm.

The high end Callis, Crower, Lunati, ect, cranks are nice. But for a 500-600hp street car, the extra $1000 spent on a crank would be better off spent buying something else. A $1000 price difference is a good start on a set of heads.

Beach Bum

Cool Beans !

Will be a pedal responsive motor without a doubt ! You'll love it.

esham

tpi 421 vette

Hey Beach, I am thinking with the right convertor and tires, this thing should run deep in the 11's.

Lemme

What vette is this going in? Is it for a TBI, TPI, LT1 or carb? Looks like something I'd be keen to do for my 84 to get it moving.

mseven

Looks like this is going to be a very nice build.

cumbercr

This is going in my 85. I'll be using a Super Ram intake. The SR is the only intake approved for Calif smog besides the stock TPI. Smog laws were the primary driver for going to a larger displacement motor. There's only so much you can get out of a 350 Super Ram motor and still pass. Once I decided to increase displacement, 396 seemed like the logical place to stop.

383vett

Nice setup. Who will be doing the tuning?

cv67

Drooling over those rods, nice stuff you got there. Keep the pics coming that will be a blast on the street, noone will see ya coming.

cumbercr

I've been exchanging emails with MSEVEN. The question is how to cope with the snail pace 160 baud ECM. The "while I'm in there" approach would be to upgrade to a newer ECM to open up tuning options. The wallet says it's been opened too many times. Not sure how this will turn out.

cumbercr

Thanks Ron. The rods seemed like a smart place to spend money. They're strong, lighter and demand less clearancing on the block. Cam clearance becomes a non issue. The machinist told Jim this was a pretty lightweight rotating assembly. Should rev up quicker.

I'm anxious to hear how your Super Ram flow test goes with my heads. Jim's made it pretty clear I'm leaving power on the table if I don't have you port mine as well.

dspencer24

Nice build you got going is he gonna ship you the engine? That looks likes an amazing combo good luck with it.

Beach Bum

Should be no problem at all getting well into the 11's.

Will pass California emissions "easily" as well..... as mine did back in the day.... just keep your single cat and smog pump in place for inspection. What won't is the long tube headers... they flunk visual unless you know somebody who will accidently miss it. I do not believe there are any long tube headers that have a carb #..... has to do with the O2 sensor placement being too far from the cylinder head on the primary.

I will say, the single cat design of the 85 corvette does hurt power substantially..... on a 396 motor such as this, a good 30 HP.... ask me how I know. The Dual cat designs do much better.

Jim, check your PM !

cumbercr

I already tackled the header issue. I'm running TPiS headers. Every 2 years I do the swap to stock for the smog check. It's a pain but the Hp gain is too much to ignore. Duals would be nice, but I would have to replace the entire system. I already have a substantial investment in a high flow cat and Corsa exhaust.

cumbercr

He better ship it to me. Actually I ordered a nice plastic shipping container for Jim to use.