The Stovebolt Site Forums The Shop Area Engine Shop '60s Pontiac OHC six

Anybody ever try to use one in an Advance Design truck? I can get one cheap that has had a recent rebuild. I know there will be motor mount & bellhousing problems. I have a BOP bellhousing for a V8. I'll have to measure it. Any other problems?
Scott

There shouldn't be any problem, that engine is the same size as the 230/250 Chevy's. As long as the cam is good, you should be all right. There are some good web site just for the engine. Does it have the four barrel and split exhaust? Joe

I don't know what it has for intake & exhaust yet. It came out of a '67 Tempest with Powerglide. The owner says they swapped for a V8. I'll go get it Wednesday afternoon. It's out in Wentzville.
Scott

I have one in my 68 Firebird. I overhauled last year, installed 4bbl, headers from Clifford Performance. The gas mileage went from about 12 mpg with the old one bbl, to around 18mpg. Great engine.

They are a neat engine, but look at the bell housing mount. I think they use a BOP bolt patern.

I just picked up the motor. It has the 1 barrel carb. PO said his kid got about 20mpg stock & that it has about 70K miles on it. The truth? Who knows. It has a timing belt, not a chain. The powerslide has a couple big holes in the case that the PO said the factory did for cooling. Not that I want an auto. I'll have to find a flywheel & see if my bellhousing will fit an SM420. I'll have to look up some web sites to learn more about this motor.
Scott

I had one years ago in a '67 Firebird. When the water pump failed I replaced it with a 350 chevy. I don't remember needing a different bellhousing when I swapped, but this was 1977 or 1978 and I don't recall all the details...

I think my solution to a failed water pump cost about twice what I had paid for the car.

Uncle Scoot, my advice for L22s remains the same - get Santucci's "Chevy Inline 6 Power Manual." He talks a bit about the Pontiac OHC 250 - the big difference is in the head. The rest is nearly (if not completely) the same as the Chevy 250s. Any GM bellhousing should fit - its the same transmission mount as the SBCs.

[img]http://www.pontiacohc6.com/images/ohc6.jpg[/img]
[img]http://www.pontiacohc6.com/images/sprintsideview2[/img]

Pontiac OHC Forum

Shure looks like a BOP bolt pattern in the photo. That was the pioneer engine for timeing belts.

Oooh, that shiny one would look great in an AD!

My brother had one of these in a 67 firebird. 4 BBl and dual exhaust. It would go like hell. Speedo went to 160. I never saw 160 but I saw it well over 100. I would think that this would be an exellent swap into an AD. He had cam problems. I helped him replace 2 of them. After it ate the 3rd cam he sold it. Weeds.

They seem to like revs better than most sixes,so final gearing might not be quite so critical. I like that engine a lot.
Speed

Looking back through old road tests in car magazines finds the high output Pontiac OHC 6 with a 4 speed runs zero to 60 in about 10 seconds. With the better tires today,it might run a half second faster.The HP was listed as 207 in most articles.The 67 Firebird probably weighs a little less than an AD truck ,so,better watch out for those kids in their 4 year old Neons,lol.

What does "BOP" mean?

BOP = Buick Olds Pontiac

Looks like the back end of my Chebby 250 to me...

The Chevy bolt pattern comes to a peak in the center on top & the BOP (Buick,Olds,Pontiac) has 2 top bolts about 6" apart. The bellhousing I have is for a V8 & the starter mounting location is a couple inches higher than the I6 starter location. The starters are bolted to the block, so I will have to find a bellhousing for an I6. I think I will go ahead with the 235 & then maybe do a swap later after finding all the parts. It's still a cool engine.
Scott