[Bill Hanlon]

I am no 4 cylinder Pontiac expert, but I read your post and thought "If he can't find a Trophy 4 cam, why not use a V8 cam?" So then I Googled "can you use a Pontiac V8 camshaft in a Pontiac Tempest 4 cylinder engine?". The answer I got was ....

"Yes, you can use a standard Pontiac V8 camshaft in a 1961–1963 Pontiac Tempest 4-cylinder engine (the 194.5ci "Trophy 4"). Because Pontiac made the 4-cylinder by essentially cutting a 389 cubic-inch V8 in half, the cam dimensions match."

... but that was followed by ...

"However, there is a catch regarding engine rotation.

The 1961–1963 "Trophy 4" (Pushrod Engine)Compatibility: The camshafts for early V8s and the 4-cylinder share the same lobe spacing, base circle, and block-mounted design.

The Catch: Some early 4-cylinder Tempests used a unique "rope drive" flexible driveshaft that connected to a rear-mounted transaxle. These specific engines rotated backwards (counter-clockwise). If your 4-cylinder is a standard, front-mounted engine, a V8 cam will work. If your Tempest has the unique rear-mounted transaxle, a standard V8 cam will run your engine in reverse."

... REALLY? I thought ALL 4 cylinder Tempests used the flex driveshaft. And I've never heard that the half-a-V8 engine turned backwards.

Anyway, if the Trophy 4 does NOT rotate backwards and you can find specs for the cam you are looking for I'd bet that you could find a Pontiac V8 cam with similar specs.

My apologies if the Trophy 4 really does turn backwards.

[1963cat]

Originally Posted by Bill Hanlon

I am no 4 cylinder Pontiac expert, but I read your post and thought "If he can't find a Trophy 4 cam, why not use a V8 cam?" So then I Googled "can you use a Pontiac V8 camshaft in a Pontiac Tempest 4 cylinder engine?". The answer I got was ....

"Yes, you can use a standard Pontiac V8 camshaft in a 1961–1963 Pontiac Tempest 4-cylinder engine (the 194.5ci "Trophy 4"). Because Pontiac made the 4-cylinder by essentially cutting a 389 cubic-inch V8 in half, the cam dimensions match."

... but that was followed by ...

"However, there is a catch regarding engine rotation.

The 1961–1963 "Trophy 4" (Pushrod Engine)Compatibility: The camshafts for early V8s and the 4-cylinder share the same lobe spacing, base circle, and block-mounted design.

The Catch: Some early 4-cylinder Tempests used a unique "rope drive" flexible driveshaft that connected to a rear-mounted transaxle. These specific engines rotated backwards (counter-clockwise). If your 4-cylinder is a standard, front-mounted engine, a V8 cam will work. If your Tempest has the unique rear-mounted transaxle, a standard V8 cam will run your engine in reverse."

... REALLY? I thought ALL 4 cylinder Tempests used the flex driveshaft. And I've never heard that the half-a-V8 engine turned backwards.

Anyway, if the Trophy 4 does NOT rotate backwards and you can find specs for the cam you are looking for I'd bet that you could find a Pontiac V8 cam with similar specs.

My apologies if the Trophy 4 really does turn backwards.

Bill, thanks for taking the time to respond the trophy 4 is indeed a half of a 389 but the problem arises due to the rod journals being 180 degrees apart and a v 8 s are 90 degrees so half the lobes will be in wrong spot. Yes the 61-63 tempest have a transaxle in the rear with a "rope drive" drive shaft which in reality a approximately a 5/8 steel shaft.

[GaryK]

Originally Posted by Bill Hanlon

I am no 4 cylinder Pontiac expert, but I read your post and thought "If he can't find a Trophy 4 cam, why not use a V8 cam?" So then I Googled "can you use a Pontiac V8 camshaft in a Pontiac Tempest 4 cylinder engine?". The answer I got was ....

"Yes, you can use a standard Pontiac V8 camshaft in a 1961–1963 Pontiac Tempest 4-cylinder engine (the 194.5ci "Trophy 4"). Because Pontiac made the 4-cylinder by essentially cutting a 389 cubic-inch V8 in half, the cam dimensions match."

... but that was followed by ...

"However, there is a catch regarding engine rotation.

The 1961–1963 "Trophy 4" (Pushrod Engine)Compatibility: The camshafts for early V8s and the 4-cylinder share the same lobe spacing, base circle, and block-mounted design.

The Catch: Some early 4-cylinder Tempests used a unique "rope drive" flexible driveshaft that connected to a rear-mounted transaxle. These specific engines rotated backwards (counter-clockwise). If your 4-cylinder is a standard, front-mounted engine, a V8 cam will work. If your Tempest has the unique rear-mounted transaxle, a standard V8 cam will run your engine in reverse."

... REALLY? I thought ALL 4 cylinder Tempests used the flex driveshaft. And I've never heard that the half-a-V8 engine turned backwards.

Anyway, if the Trophy 4 does NOT rotate backwards and you can find specs for the cam you are looking for I'd bet that you could find a Pontiac V8 cam with similar specs.

My apologies if the Trophy 4 really does turn backwards.

The timing on the Trophy 4 is different than the V8. If you want to use the V8 Cam, you have to use a V8 Crankshaft. It has been done. Not by me, but it was discussed on this forum many years ago. When it comes to the Trophy 4 and the transaxles, Google is not your friend, most suppliers don't know these cars that well either. I have been around these cars for over 45 years, I have had many arguments with people who say their parts will fit when they don't.

The main parts of the Trophy 4 that are different than the V8 are the Crankshaft, Camshaft, Distributor, Valley pan, Air Cleaner, Intake and Carb.

Search this forum for Charlie66, he has a turbo on his Trophy 4, he estimates around 800HP on his engine. There are others that getting a ton of HP out of these engines.

[Bill Hanlon]

V8 cam blanks are available from a number of sources. Maybe that would be the way to go. Who cares if there are 8 uncut "lobes"?