Thread: Here I go... the 350 buildup begins...

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Forgive me if I post in the wrong area, I havent quite figured this forum out yet.

I went north yesterday and began work on bringing my SB Chevy down to my garage to begin my "therapy." This thread will be or anyone interested in watching the progress and giving their two-cents as I go. I have taken pictures to add soon to give a better visual of what I have going on, and plan on putting this all on a web page at the end.

Enjoy and feel free to comment on what is going on!

Craig

Here we go.
This is where it will all begin. This small block General Motors 350 came from an old 1976 or 1977 Chevrolet pickup truck owned by my uncle. My dad removed the head, ten or fifteen years ago to repair a small block 400 Chevy 4x4 I used to drive.

This baby has sat for decades under a pine tree on my parents property in rural Mecosta County. In spite of the fact that the block was growing moss, and that there was enough dirt and decomposing organic material on the heads to have mistaken it for a compost heap, this puppy will be the heart and soul of whatever this project turns out to be.

The other head came off relatively easily. With the exception of one bolt which gave eventually, the entire process took less than a half-hour.

The trouble came with the distributor. 20 years of sitting, exposed to the elements froze the old distributor into the engine block—thereby effectively locking the manifold to the block. Dad went out and doused the area in ATF. We’ll see how things turn out when I get back from my BARJ conference this afternoon. I will work on getting that thing off before attempting to raise the block and get it in the back of my Express van.

While I was gone dad attempted to get the distributer off... the housing broke.
Now I will have to wait to get the thing on a stand so that I can tap it out from beneath.

The heads are now in my garage, and I have sarted to clean them up. I guess at this point I am planning on rebuilding them for the experience, but I dont know if it is worth it to put stock heads on a 383. my budget is pretty tight, and quality performance heads are quite pricey. What do you think? Can I do a sufficient rebuild and modification for a stroker with stock heads?

I think Clint Eastwood said it in a movie, "A man needs to know his limitations". So it is with cylinder heads. You need to know their limitations. Stock, cast iron cylinder heads were meant to work in a stock application and environment, from idle to 4,000 rpms where most of the work is done and provide a modicum of horsepower in the process. The runner size was designed with this low-rpm work in mind and as long as you carry through with a low-rpm design on the rebuild, you should be fine.

If it were mine, I'd limit static compression ratio to 9.00 maximum and may even be tempted to use somewhere between 8.5 and 9.0, with a matching cam to achieve a dynamic compression ratio of 8.0 to 8.25. I'd use a piston which has a flat ledge on it to match up with the underside of the head so that I could set the squish at 0.035" to 0.040" and make a viable system to run well on pump gas. A shave on the block for zero deck along with a 0.035" to 0.040" compressed gasket would work. Of course, anytime you cut heads or deck, you should carefully check for alignment before going back together with the motor.
http://streetmachinesoftablerock.com...opic.php?t=350
A stock-type HEI distributor would work for me after being re-curved so that I could run about 10-12 degrees initial ignition timing and 24 degrees centrifugal timing.

I'd choose a cam which would make power from idle to 4,000 rpms and would be ground on a dual pattern favoring the exhaust valve and 112 centerline for smooth operation. You might gain just a little more power by using 1.6 rockers.

This paper I wrote will help you figure static compression ratio.....
http://streetmachinesoftablerock.com...opic.php?t=124

And this site will help you figure dynamic compression ratio. To enter the cam info, use the intake closing point at 0.050" and add 15.
http://kb-silvolite.com/calc.php?action=comp2

since I dont know much, I am assuming that low end RPMs will be applicable to every day use, but if I am looking for formidible times in quarter mile apps, then I need to look elsewhere for my extra horses, and not at the factory heads. Is this a safe assumption?

I don't think you'll get much out of it with those heads. my buddy just built his 383 and tried to do a little trick work to his fairly stock heads. I think he did more damage than good. It was his first heads to attempt. He tried doing some combustion chamber work. Anyway he put his poorly worked heads on a $$$$$$$block and it is slow. Only running 12.8 or 13. With some better heads you can get more out of your money you spent on the block.

Originally Posted by realitycheck

since I dont know much, I am assuming that low end RPMs will be applicable to every day use, but if I am looking for formidible times in quarter mile apps, then I need to look elsewhere for my extra horses, and not at the factory heads. Is this a safe assumption?

Yes. Although someone may prove me wrong, in my opinion the best heads available anywhere are made by Air Flow Research. I'd use 195 cc runners and a cam that would make power to 6,500.....
http://www.airflowresearch.com/

As with any engine, the biggest horsepower gains are made with the heads. Not counting a blower motor....

I checked into some heads, does anyone have any insight on the following applications?

World Products Sportsman II
Edelbrock Performance

I looked into the AFR's and there is no way in heck I will be able to afford those at this point in my life.

Maybe the best bet for heads are the Vortec heads available from Summit for a total of about $650. You will spend at least $300 reconditioning the stock heads, I did and then put out $200 more for exhaust porting. At that time I was not aware of the Summit heads but I still might get them. At your early stage of rebuild I would listen carefully to the advice of Tech1 on the build up and cam selection but the Vortec heads are the best bargain for heads, although you will have to get a Vortec manifold to go with them. If you were going to get an aftermarket intake anyway just get the one for the Vortec heads. Another thing to think about is the price of gas, rear ratio and possible OD trans. If you go with an OD or a stiff rear you will need to select a cam that runs good down around 2000 rpm or you will be downshifting a lot. You need to decide whether you are building a driveable street machine or a weekend warrier that will only be driven at a track or on Saturday night when you blow your gas allowance for the week. Just my point of view and my solution was to get an R700OD with a very low ratio in 1st gear and still have the OD for the highway. Another funny thing is that although you start out with a budget, you may get into a situation where you just have to buy what you need to finish it and then don't look back at the total price! If I had thought ahead (a head!) I would have bought the Vortec heads at the gitgo!

Don Shillady
Retired Scientist/teen rodder

I am totally taking tech's advice. If I didnt have six children I may consider buying the heads he reccommended

Does anyone have any insight on the other heads... I am curious about the vortec heads I will admit, but a buddy of mine has an Edelbrock tunnel ram manifold he said he'd give me, so I have been considering that... that doesnt sound like a vortec set of heads would work with that. Honestly I am not even sure what benefit two carbs and a hi-rise manifold would "give" me, but...

Any insight?

Truth is, I am nowhere near being ready to do any of this yet anyhow.