Reverse cam
- Thread starter WENGINE
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63impaloligist
Well Known Member
That's different. Don't really see that the engine notices anything. Hard to tune probably. I think that one of the Ford diesel engines did this with the turbo in the valley.
One thing that comes to mind is the designed coolant flow that would be predominantly biased to keep the exhaust side of the cylinder head cool. There is a large difference in induced heat on that side.
Another thought is the configuration in the hotrod pictured would dump the exhaust in to the long intake ports and have no way to cool the largely unjacketed areas on those ports. for only drag racing it might survive.
Another thought is the configuration in the hotrod pictured would dump the exhaust in to the long intake ports and have no way to cool the largely unjacketed areas on those ports. for only drag racing it might survive.
63impaloligist
Well Known Member
You just made me realize that I don't see a cooling system.
I agree. I think it's neat just because it's different. You know the whole spice of life thing.
Greg Reimer
Well Known Member
I had a couple 283 engine cores a long time ago. The distributor rotated the conventional direction, but the crank rotated the opposite direction. We got curious, dissected it, and found an old Iskenderian gear drive set up in it. The cam and the distributor and the oil pump all turned the same direction but the gear drive indicated that the crank rotated counterclockwise when viewed from the front. Must have beenin fact, you should have been able to put a conventional gear and chain set in it to convert it over to either a marine application or an industrial motor. The bottom end was very conventional, so that would have returned it to an automotive power plant. Don't know what kind of starter the reverse rotation crank would have had, some starter catalog probably would tell you..Anybody ever seen one of these?
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Used to run them in are dry pond runner.
The 1st year or 2 of the 366/427 BBC tall deck truck engine GM used a direct gear drive camshaft. The cam turned opposite direction of the crank since there was no idler gear. This worked with a normal distributor and oil pump because the oil pump drive gear on the camshaft and the mating gear on the distributor were cut backwards/differently so the distributor turned in the standard direction.
Jeff
Jeff
Greg Reimer
Well Known Member
Could you imagine if somebody didn't catch that difference and tried to install that distributor in another motor?
I did one of these 366's for a customer 30+ years ago and we replaced the stock gear drive camshaft. He took it home to assemble and after a few days came back and said there was some problem with the cam & distributor not mating. Come to find out the cam had teeth cut for a chain drive cam. By then the distributor gear was buggered. Fortunately I was able to source a new distributor gear from GM and got the correct cam. I think this gear drive setup used a thrust plate in front like a Ford.
Jeff
Jeff
Greg Reimer
Well Known Member
To add to the fun and games, some marine applications used two motors mounted parallel to each other. One would be clockwise rotation, the other counterclockwise. When viewed from the top, they would have appeared to be identical. Rotational forces in a motor would attempt to impart a sideways thrust in the hull, attempting to make the boat rotate a bit when in the water. Having two motors in parallel would have the tendency for the two motors to cancel out any tendency to impart an unwanted rotational motion of the hull. I never had any experience with working on boats, but this does introduce another set of factors to consider.
Greg Reimer
Well Known Member
It just occurred to me that the reason for the thrust plate might have been because camshafts have tapered lobes, this imparts a force on the cam that tends to push it to the rear of the engine, and the thrust face on the rear of the timing gear and front of the block prevents the cam from walking out the back of the block. If the cam rotated in the opposite direction of a conventional engine, the thrust on the cam would try to push it forward. That plate would have to be there to prevent that. The timing chain and gears have no ability to control front to rear location of the camshaft.If the cam walked forward and rearward, it would cause abnormal lobe and lifter wear, and damage to the timing chain cover and the chain and gears as well would happen.None of this stuff would look nice in the bottom of the oil pan after all these parts failed.
Greg Reimer
Well Known Member
I've noticed that. The slight taper of the cam lobes apply to flat tappet cams only.That is what causes lifter rotation.Without that, the cam would concentrate its wear in one place instead of the whole face of the lobe and the cam would go flat in no time. The factory roller cams have no taper in the lobes so that the roller would carry the weight of the spring tension and the valve train over a much larger area. Roller lifters also have some form of link bar to prevent the steel roller lifter from rotating in its bore.That would do in an engine in no time flat.