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hi everyone ive been wondering something for years now ..on a 580 west bend after market intake such as palmini p27a or upgraded intake from west bend .i have always installed the intake on left side drive motors so they draw off the bottom and flipped them over on right side drive motors so they draw off bottom also .ive always wondered if i was puttin them on correct i relize a go power draws threw the center ..it seems to me the way the engines turn over it be better off the bottom ..Lol if any one has any idea as to what im even talkin about let me no whatca think ..

Hey Steve,
Actually, West Bend disagrees with you. In the instructions for their "V Power Manifold Kit" (#3191-1), which was their V-4 performance replacement for the early engines' flat reed manifolds, they say:

"NOTE: It is necessary to install the manifold so that the incoming fuel mixture is directed toward the connecting rod journal of the crankshaft as the shaft rotates......In almost every case, this will require that the offset in the manifold be installed toward the top..."

Since these engines were normally mounted with the pto side out on each side, the rotation in each case would require the offset be up (if you follow their advice) as the journal rotates toward BDC. I've spoken with people, however, who disagree and think it better to have the offset down and some who don't think it matters and place it where the desired carb positioning dictates. And, as you point out, Go Powers are in the center.

If you think about what is happening during the rotation of the crank journal through the case, you find there are lots of variables. I've never spoken with anyone who could give me the reason WB wanted the reeds there; the case is being pressurized as the journal approaches BDC and the mixture in there is not entering at that point to meet and directly cool/lube the journal - it had been forced in by atmospheric pressure as the journal had gone past BDC and was going back up toward TDC during the previous rotation.

So did they assume the density and/or temp. of the mixture was not homogenious but was more concentrated right there inside the reed plate opening as the crank journal rotated through the area? By then, blowdown is over and the transfer ports are open and the mixture is being forced along its path to the transfer ports. Or is it a spacial thing concerning the crankshaft weight on the mag side? Or a flow thing of some sort? If anyone knows for sure or wants to advance a theory, please advise.

Wow ..!! andy thanks atleast i finally had someone tell me there kinda sorta was a right and wrong way ..i have alot of magaizines and stuff like that and i never have seen anything that could really explain either way ..i always in my head figured the way the crank was spining it would help draw in fuel mixture a tiny bit better ..the other way i seemed it would sorta blow twards the reeds and wouldnt draw as good the pistons at the bottom either way right ..??? and if it draws off top it would have more time to suck in fuel ..cuz the other way it dont start for quit a few degrees later the piston just sets there for a while right ..???..thanks again andy after we get this figured out ....im gonna try make a couple right side drive motors out of left side drive with just a points cam and turn the flywheel ..?? will it work ..thanks again ..

Hi Steve,

Yeah, it is interesting. I want to visually compare port timing to crank journal position and think about this some more.

As far as making RS out of LS engines, as you say you'd need the correct breaker cam and flywheel. The keyway would have to be moved if you wished to use a LS flywheel. The crankshafts are also different but only in the threads; LH threads on the RS engine and vice versa. (If you REALLY want to nitpick, WB lists different numbers for the LH and RH nuts and also for the different lock washers! In their defense they are externally toothed).

The support plates and fan housings are different as well, being mirror images. The LS ones will work on a RS engine and the engine mounting holes will line up with a typical 580 engine mount, but since they're not symmetrical the plate and housing will stick up from the crankcase higher on the RS than the LS and the design of the housing will be upside-down. If that's not a concern you're in business. The spark plug wire hole would wind up on the bottom on the RS too but, interestingly, the correct support plate I have for my RS engine also has the factory hole exiting the plug wire on the bottom of the engine as it's mounted.

The rewind starter is listed as different but can just be re-wound for the other side. Have fun! Let me know what you decide to do about the flywheel keyway - I'd like to find out how it turned out.

Andy

hi andy ,,i did it last night ,you can run the plug wire out either hole .i used a 11084 points cam turned and lapped the fly wheel with no key .. i start most all my motors with a rope .so recoil is no big deal the reason im building a couple is im out of RS drive blower housings ..