[unruhjonny]

I believe that several years ago a budget build was done on a P350 in HPP;
A Dodge 318 piston was suggested as an option that could be made to work, as there were readily available forged piston options for the 318 while the P350 forged pistons were no longer available, except for special order - so there was certainly cost savings in buying an off the shelf forged slug versus a custom ordered part.

[ponyakr]

Originally Posted by unruhjonny

I believe that several years ago a budget build was done on a P350 in HPP;
A Dodge 318 piston was suggested as an option that could be made to work, as there were readily available forged piston options for the 318 while the P350 forged pistons were no longer available, except for special order - so there was certainly cost savings in buying an off the shelf forged slug versus a custom ordered part.

The problem with that is that when you add up the cost of the 318 forged pistons, PLUS all the extra machine work costs involved with makin them work in a 350 Pontiac engine, you're right back up into the price range of Auto Tec pistons, which would not require all the extra machine work.

So, not enuff savings to make forged 318 pistons a good idea, IMO.

I once mentioned using the Wiseco forged 318 pistons. Paul Carter mentioned that he thought the Wiseco pistons, as well as the Probe pistons ACE used to sell for 350's, are all junk.

https://thmotorsports.com/10791734-w...caAjPsEALw_wcB

https://www.cnc-motorsports.com/pts5...ysler-318.html

https://www.speed-talk.com/forum/viewtopic.php?t=23667

https://ls1tech.com/forums/generatio...tons-good.html

https://www.supraforums.com/threads/...-input.684747/

[unruhjonny]

I think the premise behind the idea was that the off the shelf forged 318 piston wouldn't require any additional block machine work - just a specific non-standard bore for a P350.
I do believe as mentioned earlier in this thread, it was suggested that the piston shouldn't require any modifications.
I believe that the 'off the shelf' 318 piston didn't require expensive rings, while the custom slug did require expensive rings.

You didn't forget that block work was a consistent cost factor here did you?
(if you haven't, what am I missing?)

I tend to follow threads like this, because I feel the P350 is not maligned per say, but more or less forgotten in leau of building a P400/P455... I think many have forgotten that the P350 responds very well to select builds - like what you have observed;
I'd wager few people really realize how easy it is to build a P350 that will surprise the pants off many other street motors.

[ponyakr]

"I think the premise behind the idea was that the off the shelf forged 318 piston wouldn't require any additional block machine work..."


Except for stroker pistons, the forged 318 pistons I've seen have a 1.800 or more pin height. Assuming this is gonna require some combination of shorter rods and/or machine work, to keep the piston top from pokin out the hole too far. 6.535 rods would require smaller rod journals, & .984 pin hole bushings for the rods, or replacing the .984 pins with .990 BBC pins, with the required piston pin hole work. I suppose the stroke could be changed SLIGHTLY, by offset grinding.

If not, somebody please explain the math to me, or post the part number of a forged 318 piston with a pin height between 1.70 & 1.80, please.

[unruhjonny]

hmm, maybe I forgot that point.

[Jay S]

Probably the writer from HPP was referring to the speedpro L2329F forged piston which was 1.759 comp height. Problem is that was discontinued as well.

If Autotech can indeed do a forged piston for less than $500 that seems like a great value. Econo wise the cast 1.749 flat top 318 piston looks like a good value as well with very little machine work. Would not take much machining to get that combo past 10:1 scr with the right cc heads. The cast 350 piston down in the hole .035 would be ok if decking is going to be done on the block. Not a big deal if it is being squared up anyway. The intake and or intake surface on the head have to be machined when that much of the deck is taken off, that is the down side to that.

My interest on the 350s is different here. I need to do some engine testing and the safest thing to do appears to be installing a 350 or 400 in our IHC 460 light limited SS pulling tractor and pull in the econoMod V8 class. The class has an 412 cid,8000 rpm limit, 4500 holly carb, cast iron heads and block. Probably will do a 400, but with a 350 the tractor can weigh more, I would be running with these guys in the front of this video...

https://m.youtube.com/watch?v=1e1glMAMMmk

[ponyakr]

"...If Autotech can indeed do a forged piston for less than $500 that seems like a great value..."


That price I got was a few years back, at least 3. So, as mentioned earlier, the current price is probably at least $550, with shipping, possibly a bit more. Haven't priced any lately. But, even of they're $600 shipped, that's still cheaper than any custom 350 forged pistons I know of.

I think the Ross pistons are over $800, with pins & shipping.

https://butlerperformance.com/i-2445...tegory:1234850

And, I think Adam Strang posted that his CP 350 Stocker pistons were about $800.

Back in the old days, I remembered that Venolia was a popular SS piston. About 5 years ago, I got a price of $73.80 each, for the piston only, plus the price of pins & shipping, from Venolia. So the current price is probably real close to the Ross price.

[pmd400]

Autotec pistons would be cost effective.
As an example the piston linked below is for an ls1
https://sandiegoengineparts.com/prod...at-top-1000594
With a 3.905 bore and 1.315 compression height they would be very good for a 4.25 stroke/6.800 rod 350. If they can be ordered with a .990 pin on a 1.300 compression height for no extra cost then we are on a winner. They also sell a 283 piston with a 1.800 height. So again with a 1.720 height and .980 pin it would work perfectly in a 3.75/6.625 350

[ponyakr]

Originally Posted by pmd400

Autotec pistons would be cost effective.
As an example the piston linked below is for an ls1
https://sandiegoengineparts.com/prod...at-top-1000594
With a 3.905 bore and 1.315 compression height they would be very good for a 4.25 stroke/6.800 rod 350. If they can be ordered with a .990 pin on a 1.300 compression height for no extra cost then we are on a winner. They also sell a 283 piston with a 1.800 height. So again with a 1.720 height and .980 pin it would work perfectly in a 3.75/6.625 350

Yeah, they could make a Pontiac 350 piston from the same blank that piston is made from. BUT, when you change the pin size, pin location, and make 'em without reliefs, the price goes up, to about what I described.

Most Chevy parts are cheaper than Pontiac parts. So, any Chevy parts you can use without mods, will usually reduce parts cost.

BBC 6.635, 6.7, & 6.8 rods can be used, with BBC size rod journals, and somehow mating the pin end of the rods with the pistons/pins to be used.

But, making needed changes to Chevy pistons might make 'em cost more. For example: I assume that it would cost extra to get those LS pistons without valve reliefs, since it would probably require a change in a computer program. It's not like it would just be less work for a machinest. It would be MORE work, for the computer programmer.

But hey, I'd be interested in knowing about any forged 350 pistons that have a flat top with no reliefs, any pin size & location available, and are less than $600 shipped, with fitted pins.

[pmd400]

Originally Posted by ponyakr

Yeah, they could make a Pontiac 350 piston from the same blank that piston is made from. BUT, when you change the pin size, pin location, and make 'em without reliefs, the price goes up, to about what I described

I’m certain they would use existing blanks for their custom pistons. I doubt they would design a new moulding to sell 8 pistons for $500.

[ponyakr]

Originally Posted by pmd400

I’m certain they would use existing blanks for their custom pistons. I doubt they would design a new moulding to sell 8 pistons for $500.

Yeah, I doubt anybody has made a from-scratch batch of custom forged pistons for $500, in a long time.

BUT, for a price, some, such as Ross, will make a from-scratch set in ANY bore size you want, if they don't have a shelf blank that will work.

https://butlerperformance.com/i-2445...tegory:1234850

[242177P]

Originally Posted by ponyakr

But, making needed changes to Chevy pistons might make 'em cost more. For example: I assume that it would cost extra to get those LS pistons without valve reliefs ...

The LS1 didn't use valve reliefs. Not on the OE stuff anyways.

[ponyakr]

Originally Posted by 242177P

The LS1 didn't use valve reliefs. Not on the OE stuff anyways.

Not an LS fan. Just going by the pic of the piston linked. Has 3.3cc reliefs.

https://sandiegoengineparts.com/prod...at-top-1000594

[Cliff R]

I think what this all boils down to is pain vs the gain.

With any of these engines and a little research and extra effort one could come up with a rod/piston combo to get a suitable overbore size and piston to the top of the block at TDC. That's exactly what they did years ago with the "stroker" 6.8" big block Chevy rods and aftermarket forged piston deal for 400's. Coming up with a "drop-in" crank for the 400 block and the rest of that deal is history.

The problem with working up combo's for the 350 is that when you are done spending a ton of money you have an under bored 400 for all your efforts. It's just way better all the way around to put the time/funds into a 400 build instead, and that's typically the course of action most folks do when it comes to this topic.......Cliff

[ponyakr]

"...It's just way better all the way around to put the time/funds into a 400 build instead, and that's typically the course of action most folks do when it comes to this topic..."


Yeah, that is indeed what MOST recommend.

BUT, there are still a LOT of 350's out there. Those who don't have one, can probably buy one, for a much cheaper price than what it will cost them to buy a good non-557 block 400.

SOME people don't need or even want 500hp or even 400hp. 300hp + is not too hard to make, with a decent 350 build. A 300-325hp 350 can make decent power, for a fun-to-drive street car. There have also probably been lots of 350 powered 13 & 14 sec bracket cars. The only 350 we ever ran on the track was in a '68 bracket Bird, back in '76. I just looked at our records. It ran 13.20's. It was nothing special. But it did have either #16 or #62 heads, TRW forged pistons, and a mild cam, probably an 068. So, it was very similar to a 350HO. Bird was stripped for racing & TJ only weighed about 100 lbs. So, car & driver probably weighed about 3100-3200 lbs. A year later, that same car ran 12.90's & 13.0's, with a very similar 400 engine. Earlier that season, had run 12.40's, with a 455 out of a '70 GTO.

For those who wanna make 400hp +, using a 350 block(for whatever reason they have), they can go with a stroker assembly. Most 350 guys know about the 462hp 383 that Ace built.

https://www.hotrod.com/articles/hppp...-engine-build/

And, most also know about the 350HO rebuild that made 330hp.

https://www.hotrod.com/articles/hppp...-engine-build/

And, I've mentioned the 350HO that was in a former Stocker I bought. It was not "All-Out", by today's standards. It made 434hp.

If you will be satisfied with nothing less than a torque number of 500 or more, then a 350 is not for you. But, if you just wanna build a fun Pontiac engine, with a little spunk, then a 350 Pontiac could be just what you need.

So, for all who just wanna tell the 350 guys they should forget the 350 & go with a 400 or 455 block build, it might be best if they would just not post their opinion about it, on 350 threads. I feel fairly certain that the 350 guys would really appreciate it. I CAN say for sure that if I post a 350 thread, I certainly do NOT wanna hear it. EVERYBODY here knows that it's easier to make more torque & hp with a 455 or 400 block stroker. So, it is absolutely NOT necessary for anyone to post that info here, ever again, IMO.

[AG]

How about some JE 0.030: forged pistons with a dome?

[Jay S]

Originally Posted by AG

How about some JE 0.030: forged pistons with a dome?

Nice looking pistons. That big dome looks like it may even have some quench or does it appear that way because it is on a small bore? Story behind those? How many cc is the effective dome?

[Formulas]

Post #13 Pontiac Ross 350 pistons used in super stock 150.00

[Jay S]

Thanks. That link would not open for me on 13.

[pmd400]

That post didn't work for .e either. I'm interested in buying them