Frankenengine identification and vibration help

[David Hawkins]

The 62 that we bought at Carlisle has an engine that's turning into a bit of a mystery. I know it's a NOM and everyone told us it was from a 67. We talked to the man who built the engine and he confirmed it was a 67 with solid lifters, high lift cam and domed pistons. He couldn't remember which heads he put in it.

The block number 3959512. The casting date is I187. My neighbor (who has a 69 Z28 Cross Ram) has a 'Chevrolet by the numbers' book and according to that, the block should be a 62-63 250HP 327. This doesn't quite jive with the September 18, 1967 date stamp, though.

The right side head has a lopsided triangle cast into it and the left side has two humps (haven't pulled the valve covers yet to get numbers). The book indicated that the triangle head was a replacement for the two hump head and differed only in that it has a boss for a temp sender and 3 accessory holes threaded into the back of the head.

Add to the mystery that the car has FI emblems, the holes in the driver's fender for the FI air cleaner and an FI distributor but the tach redlines at 5500rpm...I sure wish build sheets for 62s were available!!

We got into all of this because I've got a wicked vibration whenever I set the car in motion. It smoothes out as you drive, but the entire car shakes as you get moving from a stop. The right front wheel bearing was a little loose, so I adjusted it and that got rid of some of it...but it's still there. I also adjusted the brakes since they seemed to be dragging a little too much, but that didn't help either.

I've rambled enough...thanks for any help.

 

[David Hawkins]

Head numbers - right 3947041 L68, left 3927186 B19

The left head is a 'dual camel hump' head and should have 2.02/1.6 valves.
The right head is a 'right angle' head and could either have 2.02/1.6 or 1.94/1.5 valves. What are the odds that they're mis-matched?

 

[JohnZ]

The 9512 block was used almost exclusively as a service block (except for the '62-'63 usage) for many years - yours was cast on September 18, 1967. The 041 and 186 heads were used in '69 and '70 in both 2.02" and 1.94" valve sizes - no way to tell which variety you have without pulling them. Most 186 applications were 2.02", and most 041 applications were 1.94"; the 186 heads have 64cc chambers, and the 041's have 68cc chambers. Assuming the pistons are all the same design, you'll have about an 0.4 higher compression ratio on the side with the 186 heads than on the side with the 041 head.

 

[David Hawkins]

The 9512 block was used almost exclusively as a service block (except for the '62-'63 usage) for many years - yours was cast on September 18, 1967. The 041 and 186 heads were used in '69 and '70 in both 2.02" and 1.94" valve sizes - no way to tell which variety you have without pulling them. Most 186 applications were 2.02", and most 041 applications were 1.94"; the 186 heads have 64cc chambers, and the 041's have 68cc chambers. Assuming the pistons are all the same design, you'll have about an 0.4 higher compression ratio on the side with the 186 heads than on the side with the 041 head.

Thanks John. Would the mis-matched heads lead to too much of an imbalance in your opinion? I did find a reference that listed both as 64cc chambers, but who knows what's actually in there?

 

[JohnZ]

I have conflicting sources on the 041 chamber size too, and can't get to the NHRA specs right now that are reported by the manufacturer. Could be that both are 64cc; may not be a big deal.

 

[o2bnkc]

The 041 and 186 heads were also used in 1968.

 

[Stan's Customs]

...automatic or stick?

 

[David Hawkins]

...automatic or stick?

My car is a 4 speed - it's a 67 M21, but it's a 4 speed.

The heads are from December 68 and February 69. My neighbor got pretty excited when I told him the date code on the 186 head as it's 5 days before his car was built. He's slowly laying claim to my drivetrain (transmission, carb, head) for when I find the correct bits to match the numbers.