Well, I spoke with my machine shop this morning. I had a cylinder with a .006 ridge in the bore which was causing the engine to seize. Block is getting bored .030 over, hot tanked, new bearings, and obviously new pistons. Now, I am going to school overtime, and don't have enough time for a job. As you can imagine, money is very tight. I had some cheap Sil-V-Olite cast pistons in there before, those are going into the trash now. I had bought those off new off someone who had them sitting at home collecting dust for $25 or so.

I was talking to my fiancee today, and she wants to get me a set of pistons as an early christmas present.
I LOVE HER!!!

I've been looking through some old posts, reading up, and I couldn't feel any more indecisive. I don't know whether I should go with cast or hypereuctectic pistons. Then again, the price difference between hypereuctectic and some forged pistons aren't too big.

Well, I have a pretty much stock bottom end. Stock crank, X rods. My setup isn't too radical, I have an LT4 Hotcam, ported 416 castings, and a siamesed TPI setup. I would however consider going with a StealthRam or similar down the road, or maybe even a mild nitrous shot.

Heads have been brought out from 58 to 62/63 cc. I was looking for a compression ratio around 9.5:1, 9.7:1, or something around there. This is a daily driver, but I wouldn't mind running 93 octane. Anyone have any input or advice? I would appreicate any help or comments.

 

go with at least hypers

 

agreed. You can get a set of Speed-Pro forged pistons for only another $30 or so though and a good set of hypers. I got my Speed Pros for $225.

 

i'd use hypers over cast. tensil wise hypers are stronger than forged but are also more brittle than cast. not a problem as long as you don't get knock.

 

I was really happy w/ my Federal Mogul H631P hypereutectic pistons (2 valve relief flat tops). 5 hard years of drag racing and road courses, and they never missed a beat. Engine still blew 93%-96% on the leakdown tester when I sold it this year.

I was running 58cc chamber heads and skinny copper shim head gaskets, calculated 11.2:1 compression ratio, happy as a clam on 89 octane gas with the timing dialed down a bit. With 93 octane and the full ARAP spark map it was even happier.

 

I used the Speed Pro hypers (Jeg's part #844-H618CP30). I was very happy with the cost. I got them from the machine shop that did the work on my 355. Got them for $288.00, and that included pins, rings, rod and main bearings.

 

kevinc, the 11.2:1 compression was on alum heads correct? I can't even picture running that on iron with pump gas.

My block hasn't been decked or anything, and I know thats a big deal if you want to run high compression with pump gas. I don't know what my quench area is going to be. I was figuring that if I stayed below 10:1 I should be ok. Worst case scenario I would have to back off timing a little, although I understand thats not the ideal scenario.

 

true, but i dont think a piston will have much of a tensil load applied to it.


either way, id go with the hypers

 

Firstly, hypereutectic pistons are cast, they just have a lot of silicon (not silicone, you boob!!) in them compared to a standard casting. They shed heat better than "standard" cast pistons, and although they can crack, are generally stronger and of higher quality than a standard cast piston. The advantage of a cast pistons (including hypereutectic) vs Forged is that you can run much closer tolerances, so they will scuff less, wear better, not rock in the bores when cold, and the rings will last longer than Forged. They are more brittle, but they are really good for a hot street setup that you might sneak an occasional 100 shot of nitrous into.

If you are looking for more than 500 HP, you should consider the forged pistons, they are much stronger, but require longer warm ups and will wear more quickly because they are effectively flopping around in the bores until the get up to operating temp. I would not bother with a standard casting in either case.

 

Yup, aluminum L98 heads. Gotta manage the quench area carefully and be conservative w/ the street timing map, but it pays off big when you run Sunoco 94 octane and run ideal timing.

 

92blue: I don't know if this is much help to you now, but you can buy a complete engine rebuild kit for a 350 from Northern Auto Parts for about 189.99 or something like that. You can substitute the cast pistons for hypereutectic pistons for another $20 and add all Fel Pro gaskets for $8. That's what I did with my 350. Got the whole complete kit with Fel Pros and hypers shipped to my door for $220

 

I'll take a look at the kit you mentioned.

I was seriously considering a kit I found with a complete Fel Pro gasket set, Clevite 77 main and rod bearings, Sealed Power moly rings, and Sealed Power Forged pistons. Its $290.

There isn't much of a price difference between hypers and forged I think to forget about forged altogether.

 

http://www.northernautoparts.com/Pro...?ProductId=148

http://www.northernautoparts.com/Pro...?ProductId=282

These are the basic rebuild kits from Northern. Once you get up to 86 and up, the prices go up too.

 

Those kits are pretty decent, I almost bought one one time. But then I added the good gaskets, a better cam (they come by default with that POS 929), better pistons, etc. It ended up being 250 instead of 159 as advertised. I said the hell with it, and ordered it all seperate.

 

WOW!!!!!!!

Yawl are payin' WAAAAY too much fer pistons.

Hers some fer way lot less money.

Unless dem are kits yer talkin' 'bout?

Hers da' ones I got, and dar a hole lot cheeper den forged slugs.

Plus dey gots coated skirts, like dem fancy city gurls does.

http://www.fastengineparts.com/produ...3649a25df2f452

Translation-
You guys are paying WAY TOO MUCH for hyper pistons.

Here are some for a lot less money.

Unless those are kits you're talking about.

Here are the ones I bought, and they're quite a bit cheaper than forged pistons.

Plus they have a coating on the skirt which help reduce friction, improve seal, and increase piston stability.

BTW, contrary to popular rumors, those pistons have a compression height of 1.56", not the 1.54" that everyone thinks.

 

I ended up going with a forged set. They are Speed Pro L2256F. That last link had some really nice pistons for cheap, by the way.

 

Dang!! $88 almost sounds too good to be true!!

Kevin

 

I know!!! After I made up my mind to go with Forged and saw that, you almost convinced me to get them. If I wouldn't have had my mind set on Forged already, I would have gotten those hypers.

 

Go ahead and put a 150 shot on it. And enjoy the ride

 

Same as http://store.summitracing.com/partde...TL%2DH345NCP30, pretty much the same price and all. Basically that's just what those go for.

 

Good find RB. I actually looked until I was crosseyed for those at Summit. May I ask what "STL" stands for? I looked under Speed Pro, Sealed Power, Fed-Mog, Silv-o-lite, etc. I couldn't find them.

Anyway... this is the part that has me baffled is
Compression Distance (in) 1.540

I've measured mine, a couple of them and got 1.56". Actually 1.564", but I'm using a dial caliper... margin of error, blah blah blah.

Anyway, I've seen that printed numerous times on numerous websites, but it's nowhere on the box/label.

Oh well. I guess I have oddball pistons. :shrug:

 

"STL" is (was) Sterling, which is just another Federal-Mogul brand.... they're now listed as "SpeedPro hypereutectic".

 

By the way, the pistons I picked up will put me at 9.72:1 compression with 64 cc heads. My heads were originally 58 cc, and have been brought out to 62/63 ccs. That would put me somewhere around 9.8 ~9.9 compression. I have a stock deck height, and iron heads. I wouldn't really mind having to run 93 octane, but I would really hate to not be able to give it full advance, or end up pulling the heads and opening up the chambers some more because of neverending detonation problems. I know its a little high, but would that be fine for a daily driver? Should I bring the heads out to 64cc now before I assemble everything?