Were all Jahn's pistons forged?

[Sixcarb]

My freind is ending me a set of old Jahn's pistons and I was wondering if they are forged pistons, did Jahn's make anything else?



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Injectors

[Bruce Lancaster]

They also did cast for most applications.

[Kilroy]

I was under the impression they were of a Hypereutechtic(?) variety?

[Blownolds]

NO! Most Jahns pistons were cast, and long have been. If the underside of the piston is rough with crosshatch markings, then it is cast. If it is smooth to the feel, with some striations visible, then it is forged. But I have never seen a forged Jahns piston. Jahns did once tell me that Ross will make forged pistons to Jahns specs, because they had an agreement.

[Cadillacin Marcus]

Yep mine are cast in my Cad

[56olds-ERDY]

ive never seen forged jahns pistons either.except in adds.
my set are cast also.does anyone have a catolog that lists part numbers and aplications?
eric

[Sixcarb]

Thanks to all that replied, helpful as always.

Joe

[daveydeuce]

Back in the early 60s, Jahns were nicknamed "Peanutbutter Pistons" I bought a set of .060 overs for my 331 back in 74, been working good ever since, still going strong today even with the S.Co.T. on it. Never did hear what happened to them or if they were bought out by some other mfg. http://www.jalopyjournal.com/ubbthreads/images/graemlins/smile.gif <font color="red"> </font>

[manyolcars]

After a piston boss broke in my first 392, bending the rod and knocking a hole in the cylinder wall, I called Jahns and asked about forged pistons. They gave me a price, then told me that if I could get an auto parts store to order them, they would be half of my price. The forged pistons they sent me are beautiful and heavy. They never broke either. I still have the box they were shipped in and the bent rod.

[manyolcars]

bent and twisted 392 Hemi rod, cylinder number 8

[Cranky1]

Very old thread I know.....but if anyone is still interested, I have a set of never been used 'ash can Jahns' forged pistons for a 383 Mopar that I can take pics of. No, they are not for sale. They are very nice looking slugs and are light weight. I ran a set in a 440 roller motor in the early 80's running 10.60's. Never heard the term 'peanutbutter piston' but heard 'ash can Jahns' many times....

[Dolmetsch]

I have an original old catoalg. they made both. You can say what you want but back in they day they were the ones to run. I bought a set of 392 Forged in the 60s from them.
Don

[JeffreyJames]

Wish I could find a set for .125 over 265 Chevy (283). That would be a pretty cool detail.

[Engine Pro 5X]

I think I have a standard bore 283 set !! I'll check when I get back to the shop >>>>.

[saltracer219]

We ran Jahn's forged pistons in one of our 258 inch small blocks back in the 70's. They worked well, a nicely finished piston. Most of the early hot rod pistons that Jahn's made were sand cast, a little noisy but they seemed to hold up pretty well.

[Cranky1]

Oh I have nothing but good words for the brand. Like I said earlier, I ran them in a 10 second car in the 80's and hope the engine I have a set for now will go at least as quick...and yes, they are very nicely finished.

[davetranex]

I'm trying to identify some Jahns 409 pistons. The pistons have the
# 1138 on the inside skirt next to the pin boss. zi would appreciate any information you have. Thanks! davetranex@q.com

[Little Wing]

Race Grind or Street ?

they came in 11-1 and 12-1

[plymouth1952]

Kinda funny Jeff Jahns lives here in town he still builds car for fun he has a 9 sec pinto his grandfather started the company.

[CONNMAN]

>>>>>,in '64 ,,i had my 265 bored .125 over and bought a set of Jahns 13.5 to 1 cast pistons for it ,,ran em for 4 years 'till i switched motors to a 396 BB ,,they werked GREAT !! those Jahns pistons and a Duntov 30/30 cam was the in thing back then ,,

[CONNMAN]

<>>>>,Back in the '60's ,,you could "special order" any compression ratio you needed ,,,Dickie Harrell ran 13.5's Jahns Pistons in his 409 in '63 ,,my buddy with a B/Altered Bantom ran 14.0's in his Hilborn Injected Alky 301 in '67/'68 'till he switched motors to a 426 Hemi & ran A/Altered ,,not real positive ,,but i think those pistons were forged ,,

[cornfieldrodder]

I have a set of Jahns forged pistons in a '63 383 Dodge. They've been there since about the early '70s.

[Panneton Bros. Racing]

Jahns was a cast piston company (pretty rough too). Jahn Jr. wanted to get into the forging piston scene so they set up Jahns Engineering (later shortened to JE). This is were JE Pistons came from.

[FlatheadRoadster]

I have found an old ford flathead V8 with Jahns pistons they are marked 790 inside the piston and 314 on top. Can anyone identify these pistons for me?
Fun to know more exact what it is.

[Hank37]

Running Jahns pistons since 65 in my Caddy never had any problems with them. Still have a set of their 7.50 blower pistons for the Caddy.

[wbrw32]

Selling Jahns Pistons in the 50-60-70s.of all the pistons sold,we sold 95% cast 5% forged....Most people that wanted forged pistons usually spent a little more money and ordered"Forged True"..another old piston company from those days.

[fullhouse296]

Had a set of Jahns for a bored and stroked flatty .Very nice machine work , BUT , heavy as hell ! They were cast pistons with an eggcrate webbing under the crown .I sold them and went with Ross forged.

[garmaster]

I wanted to know if antbody could tell me who invented these jahns pistons.
Thank you

[christineman]

speaking of pistons, does anyone have a couple of extra sets of std 383 pistons they can sell? if so, email me at mel@moparmel.com

[Roothawg]

I wanted to know if antbody could tell me who invented these jahns pistons.
Thank you

Mr. Jahn

[Beep]

I have seen only one set of Jahns forged pistons. As late as 1970 he only made cast that I know of.

[Traditions Racing]

Joe, if you have any questions, just post a clean and clear picture of the underside the piston. I believe you already have your answer though thanks to the great folks of the HAMB. Traditions.

[Traditions Racing]

speaking of pistons, does anyone have a couple of extra sets of std 383 pistons they can sell? if so, email me at mel@moparmel.com
You can post in the classified section under the " Wanted " catagory. You might get more response there, good luck and welcome to the HAMB, TR.

[Rocky]

Good to hear positive things about these Jahn's pistons. I have a 347 Pontiac engine [1957] with 0.125 over Jahn's pop-ups in it for 370 cu. in. They're a cast piston and made me a little nervous but I feel better about them after reading this thread..
BTW, my machinist said they balanced out ok.

[terryemanson]

I am looking for pop-up pistons for my 261 chevy motor. Also, is there any sense in exchanging the head for a 235 head?

[plan9]

Jahns cast piston,,, 30% ... ate up an exhaust seat while chasing a lean condition. i think it would have held up otherwise.

http://i15.photobucket.com/albums/a353/plan92/bonneville2011/IMG_4804.jpg

[Panneton Bros. Racing]

Selling Jahns Pistons in the 50-60-70s.of all the pistons sold,we sold 95% cast 5% forged....Most people that wanted forged pistons usually spent a little more money and ordered"Forged True"..another old piston company from those days.Forge True is now BME (Bill Miller Engineering), M/T pistons is Arias and has been a long time.

[Truckedup]

I am looking for pop-up pistons for my 261 chevy motor. Also, is there any sense in exchanging the head for a 235 head?

Do an introduction... then search for the "dedicated 261 " thread or start a new post and you'll probably get an answer.