Logo
FULL SITE MENU

standard rotation camshaft gear direction

J

jlandon

Member
when looking at the back of the block what direction does the gear on the camshaft point. i had a reman longblock sent to me and the gear on the camshaft does not line up with the gear on the distributor wich leads me to belive it is a reverse rotation engine instead of a standard. any help is will be apreciated. the pic. below is the new engine that they sent me wich should be standard rotation but the dist. just does not mesh with the camshaft gear. also if it is a reverse rotaion is the only difrence the camshaft. or is there other difrences.

thanks jason
 

Attachments

  • P5141151.JPG
    P5141151.JPG
    76.8 KB · Views: 559
Jason, I don't know all that much about the Chrysler engines used in the Marine application. I can tell you that there are several ways to do LH and RH marine engines regarding Camshaft Rotation. Each may cause a change to the orientation and style of the two gears.

But let's back up for a momnet:
First.... is this a SB Chrysler.... i.e., 318/340/360?
If so, we are looking at the rear of the engine, as in.... SB Chrysler distributor location!
(BB Chrysler oil pump and distributor rotate oposite, I believe)

Also, all engine rotation is as though viewed from the flywheel end.
Standard Rotation engine is LH, or CCW rotation.
Reverse Rotation engine is RH, or CW rotation.

According to this, the Chrysler SB distributor rotation is CW, meaning that the oil pump is CW rotation as well, when viewed from above.
images



If considering that this is a standard LH rotation engine, and a chain driven camshaft, the camshaft would rotate CCW (same as crankshaft) when viewed from AFT.
In your photo, we are pretty much viewing as though from AFT (if SB Chrysler).
Due to the cam gear cut, this would drive the "driven" gear (the oil pump and distributor gear) CW if viewed from above (as per your photo).
This would appear to be correct for a standard LH rotation engine.

attachment.php



Here's a photo of an automotive LH rotation 360 Chrysler cam/driven gears.
Although we are looking at this from the front, the gear cut appears to be the same as what you are showing.

mopp_1105_10_o+amsoil_mopar_muscle_engine_challenge_contestants+tappet_camshaft.jpg


However, if this is a Std LH engine, and if the camshaft is chain driven (causing same cam rotation as crankshaft), this gear cut is placing a FWD thrust on the Camshaft.
Normally, a camshaft chain sprocket is the AFT direction thrust surface for the camshaft.
I do see that the block may provide for a thrust plate..... so this may be a moot point.
I think we need some Chrysler boys to chime in on this one!

Now if your engine is Reverse RH rotation, and if the camshaft is double gear driven, the camshaft rotation would be remain same as a Standard LH engine. (oil pump/distributor gear would still rotate CW)


Now if your engine is Reverse RH rotation, and if your camshaft is four gear driven (one crank gear/2 idler gears/one cam gear), then the above would be opposite, and the two gear cuts (cam and "driven" gear) would be different (not as shown).

In order to change direction of the "driven" gear, the oil pump and distributor rotation would need to change.
I don't know about Chrysler 318-360's......, but Chevy does not change oil pump rotation.... therefor all oil pumps and distributors rotate standard direction.... regardless of LH/RH engine rotation.

Does that make sense?
Hell, I'm dizzy after posting that! :D


Jason, a very simple and sure-fired test may be to bring the engine up on #1 TDC C/S.
Then rotate it in the standard CCW direction, and see which cylinder is next on C/S.
If #8 comes up...... then this would be a LH Std Rotation engine.

.
 
Last edited:
Clarification to my last comment:

If #8 comes up.... preceded by an "Intake" stroke...... then this would be a LH Std Rotation engine.
 
thanks Rick you were a big help and yes i am a little dizzy after reading all that. lol but you answered my question it is a L H rotation engine thanks jason.
 
Back
Top