Thread: Chevrolet performance 350 crate motor

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So i am planning on buying a Chevrolet Performance 350 C.I.D. 290 HP Engine Assemblies 12499529 from summit racing. I am putting this into my 1993 gmc k1500, and i plan on putting a new y pipe in the exhaust and taking out the cat converter (shhhh) but im not sure what to do with the fuel. Chevrolet performance says that they came up with that 290hp using a holly 670cfm tbi. I have heard to never use the holly tbis because they are unreliable and overpriced.... i also saw that you can put a 18psi spring in the throttle body and upgrade the fuel pump..... im not really sure what to do. Ive never done much with car engines, i can do stock repairs and such but i dont have any experiance in modifactions. What can i do to get that 290hp or close?

Welcome to CHR!

Before you get too far, go buy a book on building small block Chevys like this one - http://www.amazon.com/Vizards-Perfor.../dp/1932494847 Study all the sections and get familiar with common terms and components among the small block.

The engine you're referencing is a non-Vortec replacement (used in a lot of trucks) that is a good solid base to build on. Bear in mind that this is an 8:1 compression ratio engine that will peak at about 5500 RPM - regardless of what intake system you choose. I'd recommend that you download this document and read it.

http://www.chevrolet.com/content/dam...e-12499529.pdf

It fills in all the blanks and actually gives part numbers for Chevrolet flexplate/flywheel, harmonic balancer, intake manifold, distributor and holley 670cfm carburetor. You can buy it all from Summit or source locally.

The document also gives information on headers, H-pipe and exhaust and all the little bit and pieces you'll need.

Break in is critical as this is a flat tappet cam. Use a zinc additive in the oil.

Again, welcome and let us know what you decide!
Glenn

Glenn thank you very much for that pdf. Since the current motor has a tbi not a carb, how would i go about switching it out? Do you thing it would be a better idea to spend the extra 700$ and getting the same motor from jegs with the carb, intake, distributor, and stuff all included? it says the motor from summit doesnt come with a water pump, harmonic balencer and stuff, but would i have to buy all that stuff new or could i just take it from the 350 tbi that is currently in the truck?

In that this is your "first one" it may be best for you to buy as complete an engine as you can afford. Get as close as you can to just having a true turn-key. I'd ditch the fuel injection and go with a carb -but that's just me as I'm an old school guy.

Depending on what your funds are, there are some real deals on small blocks with roller cams that come complete pan to carb requiring very little effort to have in your truck and running. These engines have been test fired and do not need any special oil additives as they're roller cams - eliminating the potential issues with flat tappets.

This one looks pretty good to me: http://www.summitracing.com/parts/hp...make/chevrolet 350 horse and you and a buddy could have it in and running in a day!

I would definitely consider switching to a roller cam engine vs flat tappet as Glenn suggests. You may get lucky, fire your new engine on the first crank and get it smoothly up to speed for initial break in, but if not you can start eroding cam lobes with nothing more than extended cranking, chasing gremlins that are keeping you from firing. Oil additives are a must with flat tappet, but why take the risk?

Glenn that looks like a good motor. It says carb and manifold not included. What would you suggest for a carb? If i swap from a tbi to a carb, would there be any major modifications i would have to make? What about the auto tranny?

The add at Summit is a bit unclear - shows a manifold, but to be sure, I'd call ATK directly Chevy 350 Mid Dress Engine 350HP and talk to them. They make a quality line in base, mid-dress and complete turn-key. Ask them exactly what comes with each level. Again, the closer you get to turn-key the easier this will be for you. Remember that without a minifold typically means no distributor as well.

If you do opt to buy a engine without the intake manifold I like the Edelbrock 7104 - Performer RPM for Q-Jet with this carb http://www.summitracing.com/parts/sum-210216/overview/

Great performance and I love the sound of the Quadrajet secondaries coming to life.

Streetrodder Mag. has had an excellent article on the very same engine on how to get 340 hp plus and a bunch of torque out of the same Summit engine. I suggest you look it up, very cheap HP.

For alternator, it is such an easy fix, I'd say use the old one. But the starter is harder, (especially if you have headers, might want to consider a new one, and the water pump, well there is a lot to do to change that, the fuel pump is a real easy fix...

It's not the last time you will wrench on it. But you don't want to find yourself a month, or a year from now saying " for another fifty bucks, I wouldn't be working on it now.

Originally Posted by glennsexton

These engines have been test fired and do not need any special oil additives as they're roller cams - eliminating the potential issues with flat tappets.

What issues you say Dr.? Here, take a look......
http://www.crankshaftcoalition.com/w...ips_and_tricks

.

Originally Posted by glennsexton

This one looks pretty good to me: http://www.summitracing.com/parts/hp...make/chevrolet 350 horse and you and a buddy could have it in and running in a day!

Yep, looks pretty good to me too, roller cam and coming in under the $10/hp figure that it will take to build a good motor.

.

Although i wish i could get that 350 hp motor glenn suggested, i dont have much of a budget to work with.... im not really sure what i can do... i have to do this before winter comes, but i think i will only have around 2500 total by then..... im not sure. I have a real nice distant family member that used to race pro stocks at the local track and he might have a 350 or 2.... i dont know. Ill see what i can do.... thanks everybody

DrGoob, a respected engine builder who has become a friend writes an occasional column for one of the rags, and his statement was that with today's oils it's not a question of IF a flat tappet cam will fail, it's only a question of WHEN. Now there are some who will disagree, and you can roll dice if that's what you choose, but in your place I'd find a way to get a roller cam motor as opposed to taking that chance. Yeah, you can run Joe Gibbs oil and eliminate a lot of the risk, but I'm not convinced that you can find an oil today that matches what all of the majors put out fifteen or twenty years back.....

what engine do you have in the truck now------it should be a roller cam one piece rear seal block

Its the stock 350 tbi that came in the truco when i bought it