Hi all, Not a new guy but have been an absent member for a while. Thinking of building a lightweight rod using an inline six engine. Why?, just to be different. First thought was using a Ford 300 because they are bullet-proof and probably would hold up to supercharging. Except around here everyone around here wants more for one that I am willing to pay, and in stock trim they offer scant horsepower and also weigh a lot. So I have been thinking about some other choices instead and here they are: A smaller Ford inline six, such as a 250. A GM 250 six. A Dodge slant six. And my current favorite, a Pontiac 230-250 OHC six. To give you an idea, I was a teenager working in an automotive machine shop part-time when I disassembled my first Pontiac OHC six. Then the engine was way ahead of its time for an American motor and it still intrigues me now. So I figure the car I am planning will easily weigh less than 1500 pounds sans engine and trans. It will not be a race car but something that is not the usual SBC sort of thing. I would like to do a junk yard supercharge on it eventually, not turbo but belt drive. So what do you all think? What auto transmissions will bolt up to this and is this engine sturdy enough for moderate boost? Is this engine reliable enough for some low buck performance mods and an occasional romp down the drag strip? Shoot me off in another direction if any of you folks know of a better information source on this. As always, thanks for the help.
The only Pontiac 6 I ever owned was a 215 in a 65 Tempest. The overhead cam engine would be hard to find and parts hard to find also. A 250 chev makes a lot of power with improved induction & hedders.
Here's a link to a build on the Pontiac site of a 31 Pontiac with an OHC 6 There is also a tech section there for the OHC 6's http://forums.maxperformanceinc.com/forums/showthread.php?t=684299 I believe you'll find this engine a little too new for this site (66-69) Good Luck
Like the idea. You might google Clifford Performance for more 6 cyl inspiration. they have kool stuff. Had a friend with an ohc Pontiac Lemans; loved that car. Good luck, m
GMC 292. Shares a lot of parts with the 250's, same bellhousing as small/ big blocks, seven main bearings, a mild build will drive like a small block V8. Stroke is 4.120, lotsa torque. Edit: Everything you would need to know is in Leo Santucci's book.
The GMC inline 6 engines from the 50's are vastly different from the 230's-250's and late 292. and nothing from a late chev engine fits them. and very few parts will fit from a 235 &261. The late 292 was available in GMC trucks. But it actually is identical to the Chev 292. I own several late 292's. But I use 250's. The 292 is a torque monster and uses more fuel than a big block V8. I run a.o40 -250 six in my 66 CMC offy 4 bbl & hedders. It makes good power and doesn't guzzle fuel. I had a small holley on it and didn't open the secondarys for a long time. That fuel in the rear bowl went stale and gummed things up. So I adapted a Rochester 2 GC carb. Im pretty certian the Pontiac overhead cam mill requires the use of a BOP bellhousing?
Loads of support out there for the OHC-6 but going to cost much more to build than a Furd 300. Course the Pontiac will spin all day at 6K. Seems like 300s should be pretty cheap.
Ive got acollection of 300 ford six engines and parts. hedders, stock intake welded up to be a 4 bbl. 2 sets of new oversize pistons. a fresh bored block. and all the new parts & gaskets to put it together. Also a complete running engine. Like a 292 chev they have lots of torque. They used to be common around here set up on LP to power irrigation pumps. When scrap got high they went to china as scrap.
I like the idea but there are better more modern and cheaper engines. Like DOHC fuel injection sixes in import cars like BMW, Toyota etc. Some of them look pretty cool when you take some of the garbage off. If you can't stand anything but an American engine Chev trucks used an OHC straight six a few years ago. They put them in millions of SUVs and pickup trucks, should be the cheapest engine at the local junkyard. The Pontiac OHC six was an excellent engine in its day. You could buy a Tempest hardtop or Firebird with one and have the performance of a small V8 with the economy of a six. They were great but back then nobody cared about six cylinder engines. It would still be a decent engine today but you have to face the fact that it is now 50 years old, with limited parts availability and there are much better more modern engines going begging.
I worked in a Pontiac dealership in the 70's the OHC six was prone to overheating on #5 cylinder. If a guy had trouble with one it was usually that. My buddy had a Pontiac OHC Sprint 6 with 4 speed in his 48 Chev pickup the first time he built it and that thing ran like a scalded ape. I've got a 292 with 4 barrel intake and cast dual exhaust manifolds going in my 48 but I am gearing it a towards highway speeds counting on the torque a bit.
Lots of support our there for the Pontiac OHC. A guy on Inliners has done several with his newest one reaching close to 600 HP with forced induction. He's using one of my EFI intakes on it.
Although the Pontiac OHC six is a "pretty" engine (^^^^^), they are not that common anymore. So, I'd go with a 250; you'd really be surprised how much power they can make, and how good they can run. I built one in about 1976 for my 74 Nova; the most impressive engine I've ever built, and surprised a lot of different guys/cars. I just sold off my remaining six cylinder stuff about 2 years ago; Clifford 4 barrel intake and headers, and I sold them for cheap. Check out 12bolt.com; lots of products for the Chevrolet/GMC later model six, and lots of different articles. Read all of them, and I think you'll change your mind on the Pontiac OHC six. I am Butch/56sedandelivery in Everett, Wa.
The OHC Six is a cool idea. I have a 41 Pontiac Streamliner that I'd like to put a Sprint OHC and a T-5 trans in. Just haven't found the right engine, yet.
Hi Butch, Looks like we are both in Everett, not exactly a hot spot for fast cars but the Colby Ave. rod show every year is worth taking in. The reason that the Pontiac six interests are two fold. First and primarily, I think it looks cool and since my car is not to be a race car cool looking is important to me. The rod pics that Tombstone sent are just to die for IMHO. I recently have been suggested to use a Chevy Vortec 4200 instead which stock at 4.2 liter puts out an impressive 270hp. Now that is serious power for a relatively small engine and it should be pretty easy to find one cheap too. Problem is, it is not sexy at all with all the plastic stuff hiding the engine, and electronic fuel injection and fancy variable valve timing on the exhaust as well. I wonder how easy or cheap it would be to make it look and feel like a hot rod engine? Some guys have boosted this engine to over 600hp and it is undeniably a real piece of art with four valves and all aluminum block and head. 7 main bearings and deep skirt and other block reinforcements. It has a lot going for it. But OMG the plastic would have to go and I would prefer to run carburetors as well. But.... I know nothing about the Chevy 250 and a quick survey of Craig's List showed nothing either. I am thinking of scouting out the Pick a Part in Arlington and Lynwood soon just to see what they have. PM me if you like, it would be fun to yak. Randy
I'd say, .stay away from the "recently modern" injected six; nothing but problems. I had to replace TWO of those sixes in my daughter's trucks/cars. What a complete waste of money ( course she does't care), and time. I'm sticking with my previous "250" response. I don't know why guys want to whip a dead horse., and a rotting, horse at that. IF you currently have the OHV early six, then fine, if you don't have it, then don't waste your time. They were only available for a few years, and then CANNED; there's a reason for that!!! If you had a complete and original or Le Mans, that would be different, but that's not the case is it? We waste enough money/time on this hobby as is, why throw money/time at something that's just NOT going to "work"? I am Butch/56sedandelivery.
I have about twenty of the later six engines ranging from 194 thru 292 cu. I prefer the 250's same piston as a 307 and have both torque and RPM and are easy on gas. One of my 66 GMC's has a stock 250. 1/2 ton truck weighs over 4000 pounds. Granny 4 speed and tall 336 rear gears. And it pulls my loaded stock trailer with ease and don't guzzle fuel doing it. I converted to HEI ignition and put a ethanol compatable carb kit in it. Add a quart of diesel to every tank of gas to help the valve seats. There are two versions of the integrated heads. one has a two bbl carb. It isn't any good. another has a one bbl carb and I have got good service from them. You can also install a non integrated head on a integrated engine. You can install 307 pistions to increase compression.
I had a friend that raced a sprint 6 Tempest that he bought new in 67 . He bought it because it was cool and his driving record made insurance too high for a V-8. He raced it in AHRA stock optional that allowed only headers and slicks. He was track record holder at Motor City for several years. He mostly ran against the 225 Mopars . He had the 4 speed and high rpm's. He beat on that poor car and still drove it to work every day.
I have this one I bought with a transmission, I put it in my rambler, it is to long. I could make it fit with some fab work but I think im going to go v8 will sell total package 300... it has factory holes in the bellhousing to cool the torq converter...…...thanks
I bought a new Pontiac with the 250 OHC engine in 69. It was an OK engine. Mostly a 250 Chevy six converted to OHC. I am pretty sure it has the Chevy bellhousing bolt pattern. The transmission in mine said FoMoCo cast into the case. I bought Clifford 4 bbl and headers. Neither fit. Not even close.
Lots of Inliner fans here at the HAMB. But don't overlook all the info at the Inliners International Bulletin Board: http://inlinersinternational.org/
Rich, I too thought/would have guessed that the bell housing would be same as Chev until, strictly by chance, I happened onto this photo this morning on 12bolt.com website. Looks like BOP to me.....Maybe there was a change in production along the way...who knows? Really odd about the trans case saying FoMoCo....was it a manual shift? I have read where Pontiac did use a Ford spec T-85 around '63 in the full size cars with some V8's. Production expediency sometimes makes for strange bedfellows. Ray
lots of GM cars used the warner gear transmission that was the same as a ford. I think the OHC Pontiac also uses a different flywheel than a chevy 250. Most BOP bellhousings will accept a gm trans and a ford trans also. 8 hole's drilled and tapped in the mounting surface.
Mine was a three speed full syncro trans. GM did not have one at the time. So sourced theirs from Ford.
actually GM did have a full syncro trans in 69. the Saginaw was in general use by 1966 and there was a GM Muncie full syncro 3 speed also. However in 69 all the three speed pickups received Saginaw full syncro transmissions. and there simply was a shortage of transmissions. So the BOP sourced there transmissions from warner gear. You never found a ford type trans in a Chevrolet only in BOP's
I had a 215 Pontiac in a Chevy truck, obviously a transplant. Without a doubt it was the world champion of oil burners. I tried to blow it up, drained the oil and drove it around the 'hood for a good 1/2 hour. It was coming out anyway and I gave up trying to grenade it.
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