I know it was available on 67-69 Firebirds, but I'm thinking it also came in Tempests from 66-69...was it available any earlier than that? Like 64-65?? You never see these motors anymore...but I always kinda dug 'em...just a Chevy 250 six with a different head and often a four barrel carb...were they strictly a Tempest/Firebird mill???
Hey man, I am a diehard fan and user of these as i have 4 of them so far. My 53 pontiac runs a 67 Sprint OHC from a firebird. My hotrod is goin off the deepend with a completely modified one. They were available first in 66 in the Tempest and that is the most difficult ones to find. Those ones had a belt cover of aluminum which turned to plastic in 67 on. 66 thru 68 were all 230ci models and in 69 was a hotter 250 model. Nothing tho is like a typical chevy inline cept for your pointset and cap and rotor really. They use a lot of one off type parts. They were available with a low perf and a high perf option. The low perf was a 9:1 comp, 1 bbl carb, mild cam and average size valve motor, where as the Sprint motor was the 10.5:1 comp, 4 bbl carb, hotter cam, bigger valves, dual valve springs type motor. The Sprint motor came with a different head, cam, carb, and even a split manifold.
Oh and they were available in Tempest, Firebird and Lemans actually fairly common to the Lemans, yet more common here in Canada to the Firebird. Tho still a pretty rare motor to find, especially if its actually in the firebird, as most were yanked to put V8s with people not realizing the great potential these motors had. The sprint version pushed almost the same horse as a base model SBC had in it, without modification. Definitely a fun motor when they have a standard tranny behind them.
Does anyone know why were they dropped? I had heard long ago that they had a problem with crank breakage, but that seems too easy to fix with a forged crank to be the real cause of tossing out the whole engine program. Does anyone know the story? Those were quick engines without all the weight of an often slower V8.
one of my cousins has a 69' Firebird w/one of these that was his moms.....will probably never see the street again..sat in the drive way for a decade or so mucho body rust,especially the hood and around the back window....at least he now has it in the garage....if I remember correctly it has a bad oil pump( went out in the late seventys) and my tia was never able to find a replacement
I think '66 was the first year. I say that because they were available when I was a senior in Hghschool and I graduated in '66
didn't they put some pontiac sixes in late 50s gmc or chevy trucks? Seems like I heard something about that once....
Yes i said above they were available first in 66. First shown in Hotrod magazine in late 65 on the cover. My only opinion as to why they were dropped was it was too ahead of its time and the public was not ready for an inline with an overhead cam that made power with mileage as it was the age of the muscle car still. They were known to wipe out cams in the first 500 miles if proper break ins were not followed, as well they were known to have some cam oiling issues. I have ran one in my 53 for 14 years now with no issues at all and i have put piles of miles on mine. Primatech Motorsports International has EVERYTHING you can imagine for them, from mild to absolutely wild, including normal parts such as oil pumps and such that are hard to find. Thanks to them my hotrod will have a radical built OHC in it. Clifford used to sell sprint cams for them but they were only regrinds of the stock Sprint cam, nothing special where as Primatech offers awesome selection of cams as well.
I don't have my Hollander handy at the moment, but as I recall 66-67 were 230's, 68-69 were 250's. They were available in the Tempest and Firebird body styles. They also came with either a 1 bbl and sigle exhaust, or a 4 bbl and dual exhaust. GMC used Pontiac sixes in the mid 1930's until they came out with their own 228 six in 1938, I believe. They used Poncho V8's in the 1950's.
'66-'67 were 230s, and '68-'69 were 250s. The bore spacing and crank dimensions were borrowed from the Chevy six, and hot rodders have used 292 truck crankshafts in them with stroker pistons. I knew a guy with a '67 six cylinder Camaro that, after some creative hacksawing and grinding, bolted an OHC Sprint 4bbl intake to his Chevy six. The hottest of them was the '69 230hp 250. It had a hotter cam than the '66-'68 Sprint engines.
There's a Pontiac OHC forum at http://pub83.ezboard.com/bsohcsix that a friend of mine and I started many years ago.
I was in the Navy in 1966 and my good friend bought a new Sprint with the 4bbl. motor.It would rev to 7grand easily and would surprise a lot of Chevy owners.I drove it many times and was amazed at it's performance. I think what scared a lot of people off was the use of a toothed timing belt rather than a chain.Most didn't think it was a feasible way to drive a camshaft.Of course a lot of people didn't think much of Cadillac and Oldsmobile OHV engines when they came out either.
Is the motor better than a 454 chev ? I know a guy that wants to trade me a 67 with a one barrel for a 454 that needs a crank that I have.
One potential problem is that the camshaft does not ride in cam bearings in the head. It rides in a sized bore in the head. Cast iron performance cam cores were no longer available to cam grinders by the early 80's. I have been away from the cam business for around 16-17 years and that may have changed if one of the suppliers stepped up the plate to have patterns made again. Not knocking the engine choice...they were a pretty strong unit. Your mileage may vary.... Charlie
I liked the engine though it did have some warranty problems. Mostly Cams or cam bearings. A friend bought a low mileage Tempest , a '67 I think, that had the OHC 6. It had the cam/head replaced a couple of times by the dealer. His son and I changed it over to a Chevy 6 and PG when the cam went again out of warranty. That solved the cam problem but I still think the OHC 6 was a better engine. It sure had a better WOW factor when you popped the hood!
I had a67 Tempest with the Sprint package, bought new. Was a 4 gear and I put 4:56s, ran cheater slicks> Car was drag raced/street raced and had the snot beat out of it.. Never had issues. sold it at 104,000. miles with one rebuild. Geez I miss that car... Pontiac Slim
I have a 66 tempest sprint that came factory with the four barrel and split exhaust manifold and a three speed on the floor. it is a great engine and revs up super high. they came out in 66 and stopes in 69. now one wanted a six cylinder during the muscle car wars, even though it was the GM john doloreans favoite engine. it was very inovative and he liked it because it gave the pontiac a more high class european way. i still have my car and people flip when they see this technology at 1966! to me it is a great part of the GTO era.
Thanks for all the info and replies!! I remember the Red Barron show rod having the OHC Poncho six...it's a shame that more rods aren't running that unique engine!!
That Jeep M715 used a Kaiser OHC 6, also an interesting engine. Used timing chain not belt, designed for bigger Jeep trucks like Gladiator/Wagoneer.
That Jeep engine was called the Tornado. Not considered to be a reliable engine, from what I've heard...
Yeah, something about bolting an OHC head (high rpm) to an undersquare, formerly flathead, '30s design block (low rpm) that just doesn't jive.
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