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timing was reversed for RH LH on crusaders

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searayed

New member
I picked up an older SeaRay with twin 454 model 350 crusaders (84). The boat was in rough shape. I got engines running last year, they were hard to start but when running ran OK, rough idle but*tolerable. This year I decided to do a complete tune up. I found out the owner was a car mechanic, and I noticed that the RH engine was setup with firing order for LH and the LH was setup like a RH, typical for an auto mech when rotation is looked at from the front, and not by the flywheel as within the marine industry. I re did the wiring and timing and the engines start much better. Would having the timing*1-8-4-3-6-5-7-2*for a RH and*[FONT=Verdana, Arial, Helvetica]1-2-7-5-6-3-4-8 was used on the LH harm the engine? I ran about 50*hours*that way.

Thanks*in advance[/FONT]
 
searayed said:
I picked up an older SeaRay with twin 454 model 350 crusaders (84). The boat was in rough shape. I got engines running last year, they were hard to start but when running ran OK, rough idle but*tolerable. This year I decided to do a complete tune up. I found out the owner was a car mechanic, and I noticed that the RH engine was setup with firing order for LH and the LH was setup like a RH, typical for an auto mech when rotation is looked at from the front, and not by the flywheel as within the marine industry. I re did the wiring and timing and the engines start much better.

Would having the timing*1-8-4-3-6-5-7-2* for a RH and *1-2-7-5-6-3-4-8 was used on the LH harm the engine? I ran about 50*hours*that way.
Click to expand...
No... not at all!
Reason: Neither engine would run with the incorrect firing order.

Revisit the RH LH thing.
Somehow you've got to be mistaken with regard to the engine orientation, thus the firing order.

Engine rotation is always determined by viewing the engine from the flywheel end.
This applies to I/B's in straight or V-drives, and/or I/O's.

This is a RH Reverse Rotation example.
images


The firing order still begins with #1, but the successive cylinders (..... 2-7-5-6-3-4-8) are just oposite from Standard (1-8-4-3-6-5-7-2)!

images



Edit:
Here's one more for you.

Note the distributor rotation direction..... this will the same on either engine since we DO NOT change oil pump direction.

DO NOT confuse yourself with the notation regarding "viewed from forward end".
We DO NOT use front crankshaft rotation to determine engine rotation..... this is simply a notation ONLY.

attachment.php





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Don't confuse "engine rotation" with engine position - two independent items. Rick's last graphic is typical of most installations but not all. Reason being as some gear ratios (in the velvet drives) "reverse" the input and output rotations while in gear. This means it is entirely possible to have a LH engine installed on the Starboard side.

An engine won't run is the spark plug leads are installed "backwards" wrt their correct firing order.
 
makomark said:
Don't confuse "engine rotation" with engine position - two independent items. Rick's last graphic is typical of most installations but not all. Reason being as some gear ratios (in the velvet drives) "reverse" the input and output rotations while in gear. This means it is entirely possible to have a LH engine installed on the Starboard side.
Click to expand...
Good point, Mark.
Keep in mind that even with this type installation, the engine rotation is still determined by the flywheel end..... regardless..... and even for those Goofy Chris Craft front crankshaft drive scenarios.
 
The engines rotations are what I said, but someone looked at the rh engineg(at flywheel) probably from the front thinking it was a LH rotation and as well looked at the LH (looking at flywheel) from the front thinking it was RH and thus put the wires on wrong, it still run, and ran OK, a little rough and was hard to start but still ran.

Note the engines are in an 84 searay 390 express and the port engine is actually RH and the starboard LH, the transmissions has a reduction gear whch also changes the prop rotation. I was just supprised how it ran with the firing like it was.
 
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