Cadillac 331 pistons

[NormS]

The 331 heads have a rather large combustion chamber, so the target of 9:1 may require a small dome.

[pdq67]

Racetec can make you a custom set in their AutoTec line

Their AutoTec customs are quite economical compared to everyone else's customs.

If you need any help with it I'm a dealer

Go to this page below and click the 3rd link for custom order form

http://racetecpistons.com/pages/forms.php

OK, then please post up what they want for these.

"by pdq67 » Tue Aug 21, 2018 5:01 pm

I will say that way back in say the early '70's when I put my old junk301 together, I bought W/JCW steel-strutted cast 1/8" over 283 pistons that had 1/8" tall 1/2 round domes like the 290 and 315hp engines had.

Cost all of $39.95 per set of 8 or so back then. I ran the dog-shit out of them! Many a 7,500 rpm blast!

I think they were either Badgers or Simplex/Triplex(??). I went to buy another set for another 301 and couldn't find them anywhere.."

pdq67"

I'd have to know specifics to give an accurate quote as there are options available on a custom piston that can vary the price.

If you'd like to PM me with specifics I could give you a quote but I suggest you sit down before you read it because the pistons are going to cost a bit more then $39.95

Just stock type, 1/8" overbore 290/315hp/283 pistons!

pdq67

[pdq67]

Actually, the compression height for the 331 Cadillac is 2.093". I found very few other engines were even close to that. From my initial measurements, it looks like I'll need a compr height of over 2.105" to get closer to zero deck. I'm trying to close up the quench clearance to around .035", so that this engine has better detonation resistance on the crappy pump gas that it will be running on. I was assurred that the taller AutoTec piston forging could handle this increase in compr height.

Tight quench is always good but keep in mind when the Caddy engine came out in 1949, low octane fuel was very common.I believe that was the "Kettering" engine head design, reasonable compression on crappy fuel?

Please post a link about this.

I have looked before and really never turned up much.

As for the old Olds engines, it was said that they would be good to 12 to 1 CR when fuels were made good enough to use!

Olds finally got to something like 10.5 to 1 before the old engines were canned if not mistaken. Fuels never did get good enough for them to run 12 to 1 CR back in the 50's..

pdq67

[engineguyBill]

Yeah, there were virtually no fuels available in the 50's and 60's that would support 12:1 compression ratios. Racers in the day brewed their own concoctions, using Benzine and other chemicals to handle the high compressions and/or boost derived from supercharged engines.

[pdq67]

I forgot to say is, "Jahns Pistons", still around?

If so, they might be able to make them.

I forget if they are the, "J", in, "J-E", or not?? Sorry...

pdq67

[engineguyBill]

Jahns pistons is now owned by Grant Piston Rings in Ahaheim, CA but they are no longer making pistons, they own the name and the piston manufacturing equipment last I heard.
No, there has never been any connection (name or otherwise) between Jahns Pistons and JE Pistons. JE was short for John's Engineering.

HISTORY:
Back in the 50's or 60's two brothers were in the piston manufacturing business (can't remember their last name now) in California. One of the brothers wanted to make just OEM and aftermarket (stock) pistons and the other brother (John) felt there was a lot of potential in manufacturing high performance forged pistons for the racing industry. So John split from his brother and started a high performance piston business, called John's Engineering and ultimately shortened the name to JE Pistons. At one time Harvey Crane, Jr owned JE pistons and he ultimately sold the company to Barry Calvert and Wayne Brooks. Barry Calvert is currently CEO of CP-CARRILLO and Wayne Brooks owns RaceTec Pistons. RaceTec Pistons currently occupies the building where JE was located when they purchased the business from Crane.

I am relying on memory, concerning these details, am sure that DaveC will enlighten us if any of the facts are incorrect . . . . .

[piston guy]

Pretty close. Bill Pendleton began "Jahns Engineering" .For a short time Jahns and JE logos were on their blanks at the same time. My father worked at the Lacy street address drilling pin bores. At some point Bill moved a ways away to Monterey Park an LA suburb. Harvey bought JE from Bill in '76 IIRC and had two of "his people" run it after moving the operation to Huntington beach where his west coast warehouse was already located. It took about two years for Harvey's guys to run it into the ground ( neither knew a thing about piston manufacturing). At that time , a mid western boat racer Wayne Brooks ( also a wizard at the "new fangled" CNC machining equipment) was tired of getting what he called poor tolerance pistons and approached Harvey ( who he used for cams) about buying JE from him. Wayne bought it and needed staff so he hit up Barry , Snake , and Dave Calvert ( who were THE guys to talk to at Arias ) and hired them. Wayne and the Calverts DID change the face of custom piston manufacturing forever by making CNC machining the standard of the industry. Barry did eventually become a small percentage partner with Wayne but left JE in '97 or early '98 followed by his two other brothers. Wayne sold JE in '99 to the Dover Corporation but still felt he had somthing to show the piston manufacturing world so after his 7 year non complete clause was up he started Racetec. Barry had beat him to the punch by starting CP Pistons shortly after leaving JE ( partnered with Pankle out of Austria who is now sole owner of CP pistons). CP is a MAJOR force in the custom piston market having bought Carrillo rods from JE years ago. Racetec will continue to make high quality parts without the goal of being as "big" as the others out there.

[engineguyBill]

Hi Randy,
Thanks for filling in the gaps related to this information. I am truly impressed by the machinery and processes you guys (modern piston manufacturers) use to manufacture very high quality and aesthetic pistons.

[bigmike]

Pretty close. Bill Pendleton began "Jahns Engineering" .For a short time Jahns and JE logos were on their blanks at the same time. My father worked at the Lacy street address drilling pin bores. At some point Bill moved a ways away to Monterey Park an LA suburb. Harvey bought JE from Bill in '76 IIRC and had two of "his people" run it after moving the operation to Huntington beach where his west coast warehouse was already located. It took about two years for Harvey's guys to run it into the ground ( neither knew a thing about piston manufacturing). At that time , a mid western boat racer Wayne Brooks ( also a wizard at the "new fangled" CNC machining equipment) was tired of getting what he called poor tolerance pistons and approached Harvey ( who he used for cams) about buying JE from him. Wayne bought it and needed staff so he hit up Barry , Snake , and Dave Calvert ( who were THE guys to talk to at Arias ) and hired them. Wayne and the Calverts DID change the face of custom piston manufacturing forever by making CNC machining the standard of the industry. Barry did eventually become a small percentage partner with Wayne but left JE in '97 or early '98 followed by his two other brothers. Wayne sold JE in '99 to the Dover Corporation but still felt he had somthing to show the piston manufacturing world so after his 7 year non complete clause was up he started Racetec. Barry had beat him to the punch by starting CP Pistons shortly after leaving JE ( partnered with Pankle out of Austria who is now sole owner of CP pistons). CP is a MAJOR force in the custom piston market having bought Carrillo rods from JE years ago. Racetec will continue to make high quality parts without the goal of being as "big" as the others out there.

That was some good information... thanks! Would you know anything about the old Mickey Thompson pistons?
If I remember right they came out of Long Beach CA.

[pdq67]

Weren't some of Jahns pistons, "sand-cast"??

And thanks everybody for the historical info!!

pdq67

[engineguyBill]

BigMike,
Mickey Thompson machined his pistons, using blanks that he sourced from a variety of suppliers. This was before CNC machines were used in piston manufacturing, therefore the pistons were machined the "old fashioned" way. This meant that the cam shape and barrel shape were machined by very highly skilled machinists. Yes, I believe that you are correct, Mickey Thompson was located in Long Beach at the time.

pdq67,
Yes, all Jahns pistons were cast. They did offer some forged pistons in their line at one time and I believe that they sourced these items from ForgedTrue. I think ForgedTrue was the company that Bill Miller acquired when he went into the piston business.

[Pro-SeriesFab]

Any reason why you can't bore the cylinders out .006-.007" and run some 97mm stuff? There's a couple of interesting choices there.

The obsolete stuff generally has a much higher piston compression height than newer engines. FWIW, the Cad 331" has a 2.010" compression height.

What are the heights on the 97mm you were suggesting?

I usually don't worry about the rod length . . . seems like the easiest piece of the puzzle to have custom made but I guess if you are on a "budget" that might be a concern.

My thought was getting a modern piston in 97mm and better ring package and then letting whatever compression height you get with those pistons running those numbers through some rod manufacturer to connect the two dots.

I'm doing an 80s 4 cylinder right now with 2012 cbr1000rr pistons. You can get takeouts for dirt cheap and they are 1mm over my bore size. I'm $200 in a set of 4 with new rings. 1.3L with a much longer rod than the stock 1000rr. Just something to mess around with . . . gonna try a bunch of off-the-wall ideas and see what sticks considering I can get the motors for almost free.

[piston guy]

M/T used Alcoa forgings and experimented with magnesium and other odd alloys for pistons. Mag was not a good choice even when a special Dow coating was applied. He only made pistons for about four or five years. Mainly small block Chevy and early hemi parts. Back then piston skirts were "cam ground" on an actual crank/cam grinding machine . Ovality was done off of a "master" , the taper was set like is was for a cam lobe. They were crude compared to what is on the market now , but did the job.

[PackardV8]

M/T used Alcoa forgings and experimented with magnesium and other odd alloys for pistons. Mag was not a good choice even when a special Dow coating was applied. He only made pistons for about four or five years. Mainly small block Chevy and early hemi parts. Back then piston skirts were "cam ground" on an actual crank/cam grinding machine . Ovality was done off of a "master" , the taper was set like is was for a cam lobe. They were crude compared to what is on the market now , but did the job.

pistonguy, you might comment on the piston-to-wall clearance required in the bad old days of M/T, ForgedTrue, et al, as well as the weights thereof. Looking at today's jewels versus the full-skirt stuff from the early '60s is a reminder of how far we've come.

[bigmike]

M/T used Alcoa forgings and experimented with magnesium and other odd alloys for pistons. Mag was not a good choice even when a special Dow coating was applied. He only made pistons for about four or five years. Mainly small block Chevy and early hemi parts. Back then piston skirts were "cam ground" on an actual crank/cam grinding machine . Ovality was done off of a "master" , the taper was set like is was for a cam lobe. They were crude compared to what is on the market now , but did the job.

Thanks the reason I brought up M/T pistons is the 1st Drag car I bought around 1980 (1967 Camaro) that had a engine that had been in around 3 cars that I knew of. Eventually I blew it up It turned out to be a 283 Block bored to 4.000 and had a welded up 327 crank with 3.562 stroke. The pistons were M/T
It stated on them somewhere. Perhaps full name can't remember. They actually wore very little and seamed to be well made. The Domes on them were gigantic they must have been over 13:1 compression. I don't think I ever saw any M/T pistons after so the four or five years makes since.