Thread: pistons

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I am getting ready to replace the pistons in my 350 Chevy. I am on a really tight budget, but I have a block that I will be boring over .030 within the month. What are reliable and affordable choices for the new pistons and rings?

Remember I am the new guy, and this is my first rebuild/performance upgrade. So I apologize for any questions that are redundant or silly.

Peace.

Craig

What else are you planning to do to the motor while it is down.

As much as I can. This is as much a learning experience as it is a project to build on in the future.

I cant afford to do things like the hi performance aluminum heads my gear head kid talks to me about. So he and I will likely be porting the factory heads that I have already.
That was really as far ahead as I had thought.

Without going too deep into personal situations and rationalizations, this will be a long work in progress. I am not even sure what it is that I am aspiring to build here. It is more therapy than anything

Suggestions on what I can/should?

"It is more therapy than anything"

Bingo!! I practice this hobby for myself and friends of mine, not for monetary gain, so I can stop and start without notice and to suit myself.

The cheapest overbore rebuild would be with cast pistons, cast rings, rod and main bearings, oil pump and timing chain set. A little more dough will rebuild the heads and replace the cam and lifters.

Good, cheap therapy also dictates that the block should be ground and sanded inside and out, removing all sharp edges and casting flash. It can then be primed and painted the color of your choice outside and painted internally with General Electric Glyptol to prevent any hidden sand pockets from coming loose and falling into the lube system. Overkill? Of course it is, but it's also good therapy

One point I will mention,something I learned the hard way was that if building a performance engine check 'all' the spec's. on the pistons before you buy.Some aftermarket piston mfr's. make 'replacement' pistons to sit lower in the cylinder than the factory pistons.This can reduce engine compression considerably and of course reduce power.But that can be bad or good,depending on intended use of the vehicle,power output desired,etc.,etc. But again,depends on how much performance you desire.If your building an everyday street car most would probably suggest staying under 10:1 and that would be safe 'and' practical.

There is a possibility I may have found a 400 Chevy crankshaft....

Would I be crazy if I started thinking stroker?

Crazy, no, not at all. Out of your intended league, possibly. The stroker motor will (I believe) require new work to be done, as well as upping the price of the build. And for the new guy(such as myself), I think that a stroker motor without proper research, literature and experience would be a little too much if you want to complete this therapy anytime soon.

The 400 crank requires the main journals to be ground down to 350 specs, not a cheap job. Then there's clearancing the block, and special (not cheap) pistons. Not a job I'd wish on anyone who isn't after lots of power. Stick with stock parts, if it works out, go crazy on the next one!
Badger cast pistons are reasonably priced, and work as long as you don't run them at high RPM for long periods.

Originally Posted by realitycheck

There is a possibility I may have found a 400 Chevy crankshaft....

Would I be crazy if I started thinking stroker?

Nope, not crazy at all. BUT and a big BUT, That cast 400 chevy crank is old and used, and maybe all used up. Firstly, the 400 crank is externally balanced and is balanced for the shorter 400 rods. The 400 rod is lighter because it is shorter, the only problem is this the shorter rods have a higher side thrust as the piston moves up and down the bore. This increases bore wear. This was noted when the 400 blocks had to have a rebuild at earlier intervals than any other chevy motor. So you have a crank that is over 20 years old, it is cast iron, and it needs to be machined, if you want to run the longer chevy rod 5.7 inches in length, it has to be rebalanced. All this cost is going to stack up in a hurry.

Here is the easy and slightly more expensive way with new gear. It is proven because this is what I have done. Get an Eagle crank kit. This contains an eagle cast steel crank that is radiused on all the journals and oil holes it is already balanced for the 5.7 inch eagle rods you get with the kit it is internally balanced so you dont get any crank flex, it is stronger and brand new. My kit cost me here in New Zealand 1199.00 NZD. For this I got new hyperutectic pistons, new rods, new crank, gasket set, rings, main rod and cam bearings. Remember our dollr is worth US .62 cents plus freight and taxes on top of that. So you should be able to do a lot better. 2 things you should do with this kit, polish the bearings and get the crank and everything that attaches to it balanced. The 383 is a great street motor you dont have to rev it to make power on the street it has heaps of low down torque.

Other issues ? you have to clearance the block and check for cam lobe and rod interferance. but you can do this by setting up the crank in the block and grinding with a dye grinder with a carbide cutting tool. Camshaft: my preference on this baby is crane powermax solid lifter f-278-2, I am sticking a blower on top of all this, and am running 8.5 / 1 compression, But crane states that naturally aspirated you are advised to run 10.5 11 / 1 static compression ratio. To be absolutely sure give crane cams or you favourite cam grinder a ring to work out exactly what you want.

Hope all this explains some . S

here is an ebay item 8063487159 it is an eagle externally balanced cast steel kit with all the bits, including balancer and flexplate for a buy now price of $819.00 + freight + tax. could be worth a check.