[ponyakr]

Originally Posted by lust4speed

Getting back to deck height, here's what SRP pistons thinks about it. Had a friend not notice their stated deck height (and resulting pin location) and pistons ended up way down in the hole. He couldn't return the pistons so he had to cut the block. SRP piston page

Yeah, I don't doubt that. Their 400 pistons have a 1.690 pin height. That's the shortest I've ever seen.

Even the 8VR rebuilder pistons have a 1.700 pin height.

Wonder why they chose that short pin height for those pistons ?

The forged SP 400 pistons are 1.714, & several other brands are 1.720. Just don't make sense to me that a piston company would not do a little research, & come up with a better pin height. I know that Auto Tec DID offer to change the pin location, for no extra charge, for their shelf pistons. Their 400 pistons show a 1.70 pin height. But, I assume they could move it quite a bit. Don't know what the max safe pin height would be, using their shelf blanks.

https://shanonsengineering.com/produ...at-top-pistons

[Mr Anonymous]

Originally Posted by ponyakr

So, with all this in mind, would you say that some lighter, stronger 760g H-beam rods and the L2323F forged pistons should make a very strong bottom end, easily very safe to 6000 rpm, with the 400's 3.75" stroke ?

Since the exact failure point of any given combination is impossible to predict, I would cautiously say it might be ok.

I eventually became one of those guys you talked about later in your post, with the custom pistons, aluminum rods, big roller cam, etc. There is so much fun to be had between 6,000 and 7,500! Let go of the button, and see nothing but sky out the windshield....

[ponyakr]

Originally Posted by Mr Anonymous

Since the exact failure point of any given combination is impossible to predict, I would cautiously say it might be ok.

I eventually became one of those guys you talked about later in your post, with the custom pistons, aluminum rods, big roller cam, etc. There is so much fun to be had between 6,000 and 7,500! Let go of the button, and see nothing but sky out the windshield....

LOL !

Yeah, drag racing & going quick is fun.

BUT, this is the street section. And this engine will be MOSTLY street driven.

And, since we've raced factory cast piston, cast rod 400 engines for hundreds of passes, in several different engines & cars, without any rod or piston failure, I'd think it is a REAL safe assumption to say that forged Speed Pro pistons, should do at least as well as the all cast parts, and SHOULD be MUCH stronger, and should be safe to a much higher RPM.

I don't think anything I just said is even disputable. I can't see an SP forged piston, or an H-beam rod failing, at 6000 rpm or below in a mild to moderate 3.75 stroke 400 Pontiac engine, assuming the engine is built & tuned correctly, and has plenty of good oil in it.

Hey ya'll, this ain't rocket science. And MOST low budget Pontiac street guys don't want 500+ hp. 350 to 400hp will satisfy MOST street guys. And MOST of 'em stay under 5000 rpm MOST of the time. So, big power above 5000 is not what they need or want.

Things have really changed in the Pontiac community. Back in the old days, 350hp & a high 13 sec Musclecar was cool, & lots of fun. Sure was to me. But, most forum guys now seem to think a 12 sec street car is low buck junk, & shouldn't even be allowed. Bad attitude, IMO. And, we're all entitled to ours.

For those who only consider high dollar high power engines worthy of consideration, it might be best for all of you guys to just stick to the race section. Low buck guys need help & good info, rather than criticism for building only what they can afford. Again, that's just a personal opinion, & not meant to offend anyone.

Every member is free to post his opinion, regardless of what that opinion is. Ain't this a great country ?

[Scarebird]

Ponyakr, I think you are reading too much into this.

Just because a motor is a lower horsepower does not mean it will be a cheap build - there is a fiscal floor to speak which common sense won't breach as it will result in a weak foundation regardless of power involved.

[ponyakr]

Originally Posted by Scarebird

Ponyakr, I think you are reading too much into this.

Just because a motor is a lower horsepower does not mean it will be a cheap build - there is a fiscal floor to speak which common sense won't breach as it will result in a weak foundation regardless of power involved.

Just curious. How would H-beam rods & forged Speed Pro pistons make a "weak foundation". Just because the SP forged pistons are heavier, don't mean they are weak, does it ?

http://forums.maxperformanceinc.com/...0&postcount=39

I'm thinking now of all the Pontiac engines, including lots of 455's, which have been raced, thru the years, with forged TRW or Speed Pro pistons. Adam Strang even mentioned running them in his Stocker, back in the day. His stick cars run pretty hard.

[Scarebird]

They don't - but neither are they budget pieces.

[ponyakr]

Originally Posted by Scarebird

They don't - but neither are they budget pieces.

Nowadays, I'd consider $300 for a set of forged pistons a "budget" price. That's because most of the big name pistons guys on this site buy & recommend cost at least twice as much. And some cost $700-$800. The only cheaper way to get a dish piston, for a Pontiac 400 is to buy cast pistons. And on this thread, most of the guys have trashed all cheap cast pistons.


These L2323F forged pistons are only about $300. That's even cheaper than the L2262F Pontiac flat tops. And with those you'd have to pay to have 'em dished, and pay to have more cut off the deck. SO, why do you say $300 is NOT a budget price?

https://www.jegs.com/i/Sealed-Power/...23F30/10002/-1

And, for the rods. I think it has been posted here many times that it now costs well over $200 to have cast rods correctly resized, with new ARP bolts. I have posted many times that I consider the lighter, stronger RPM H-beam rods to be a bargain, at less than $200 more than resized cast rods. So, how is $400 for new H-beam rods not a bargain ? Eagle H-beams are at least $80 higher.

http://www.racingpartsmaximum.com/sa...elhbeam-2.html

RPM no longer lists the 5140 Pontiac rods. So, I suppose the Eagle 5140 rods are now the only 5140 forged Pontiac spec rods made. And those rods will only save a few bucks. And they're much heavier than H-beams. But, I suppose they ARE absolutely the cheapest forged Pontiac rods sold today, unless there are some cheap Ebay rods I'm not aware of, which is possible.

https://www.jegs.com/i/Eagle/356/SIR...BoC-VAQAvD_BwE

I consider $700 for forged rods & pistons a bargain, at today's prices. Opinions differ.

I bought several sets of forged TRW 455 pistons for $100 a set, back in the '70's. At only $300, considering inflation, they're actually cheaper today than back then. And the Chinese forged rods are much cheaper than the Pontiac Crower rods were, back then.

So, I suppose everyone can agree that resized cast rods & cast pistons are absolutely the cheapest way to rebuild a Pontiac 400, if only considering the initial purchase price. BUT, I ASSUME most of us can agree that forged rods & pistons are probably a better way to go. So, if somebody knows of a cheaper way to build a dish piston 400 engine, using forged rods & pistons, by all means, post that info. I always like to here of a better price to accomplish the same goal.

[ponyakr]

Just looked on the Wallace site. There are all sorts of lists, with parts numbers for lots of old Pontiac parts.

So, I'd like to ask if anybody knows of any online source that might have part numbers for Pontiac factory pistons, covering the years 1967 thru '79.

[ponyakr]

Well, I just got a reply from Paul Carter.

He said those pistons were Icon pistons with a 14cc dish, which he sold the OP. Also said the OP bought some good rods to go with the Icon pistons.

But, I got a close up of the piston he OP posted, showing the new pistons installed in the block. Stamped on the piston top is 369P .040. That's a sealed power cast 455 Olds piston, in a .040 oversize. Maybe Paul got this engine confused with some other engine. He's built so many, it's entirely possible.

https://forums.maxperformanceinc.com...3&postcount=25

https://www.summitracing.com/parts/s...ake/oldsmobile

[NeighborsComplaint]

The whole time I am reading this the old adage "JKust because you can doesn't mean you should". Buy the pistons made for the engine and break any sharp edges on the eyebrows that contribute to detonation before installing/ Personally, a Speed Pro forged piston is just about the cheapest insurance you can buy even it means rebalancing the crank for the added weight. There are places you just don't cut corners. Pistons, brakes and parachutes all come to mind.

[Steve C.]

"Pistons, brakes and parachutes all come to mind."

Adding to the list...... rods.

[NeighborsComplaint]

Originally Posted by Steve C.

"Pistons, brakes and parachutes all come to mind."

Adding to the list...... rods.

Truth

[ponyakr]

After I sent Paul a link to pics showing the Olds pistons, this is what he said.

" No, you're right. I guess we did sell him some cast olds pistons. I don't remember that at all. I do not show anything on his invoice about narrowing the rods, and I don't remember anything about that..."

Many thanks to Paul for checking his records & getting back to me ! I know he's busy.

I know people here don't like cast pistons. But, I'd MUCH rather use the 369P cast pistons than the 8VR cast pistons, in a 400 build.

Would also buy the $300 forged L2323F pistons, instead of paying $600 or more for the high dollar Pontiac pistons. $300+ is a considerable savings to low budget guys.

Keep in mind, I'm talkin a mild to moderate 400 street engine, that requires a small dish.