Crank Timing

[Patch11]

Right, now that I am a master engine builder (due to Sam's great instruction ) and much hair pulling, knashing of teeth on my part


Anyone else notice/find that the No.2 cylinder is not actually 90* to the No.1 cylinder - mine is 87*


I assume that's why we can buy an ignition module to correct stuff like this this is assuming I'm absolutely spot-on with my measuring


Just a thought on what the actual Master Engine Builders have found

[Chris]

Dude, if Sam says its good its good

I have no idea how you know its only 87deg, I'll find out some day I have no doubt. So until I join the league of Master Engine Builders like yourself and Sam obviously, I'll just say, well found out

How far have you got with the shelf anyway? I like how clean your engine is now mine will never be that clean until it comes out (hope that it never HAS to come out)

[Patch11]

Sam was just schooling me on the timing etc - I haven't/didn't mention what I found. Thought I'd make a thread instead, that everyone else can input and we can all learn.

It's not that hard to measure. Its a 90* V-Twin, which is as it says/means the cylinders move 90* to each other.

A pic would have been easier but since I didn't

Easiest way is to give each cylinder their own pointer at true tdc, place no.1 cylinder at 0* and observe what number the no.2 cylinder is pointing at. Mine was at 87*.

Given it would be slightly out due to casting, machine tolerances etc but 3* that's abit.


A good mate of mine has been schooled by the V8 lads (old skool ) and they take that pretty seriously even going as far as re-machining cranks, cylinders etc to make it near perfect.


Will be interesting to see what the others more knowledgeable will have to say about it


An engine should always 'come out' just ask Del

The shelf you ask? you will have to check the other thread ya cheeky monkey

[The Ring-In]

its why you need to use a positive stop to judge TDC.


no way is the angle out.

[tillerdog]

the rods are on the same jounal,it would be only off 90 if the cases were not machined 90 ,the v8 guys have many crank throes and are refering to cylinders being out of fase,this could be related to un-accurate crank build,basically it is impossible for our engines,unless suzuki feked up..machining a crankcase,not likely

[doug]

Need to think about this a bit. Very curious thinking out loud here if the length of the rods, cylinder height would enter into this a bit, easy to be out 3 degrees though if you are not using a positive stop to determine tdc, ie using a dial indicator instead. I guess the other way to check it would be next time I have a pair of case just bolt them together and use a couple of striaght edges and a machinists angle finder to look at the included angle.

[The Ring-In]

so I just measured the cases and they are 90degrees.( the big 4 are not likely to stuff this up)

such misinformation can become problematic if not checked.

if you haven't experience in locating TDC then its very easy to get wrong.

[doug]

Originally Posted by The Ring-In

so I just measured the cases and they are 90degrees.( the big 4 are not likely to stuff this up)

such misinformation can become problematic if not checked.

if you haven't experience in locating TDC then its very easy to get wrong.

If you measured the cases and they are 90 degrees there is one more place to look at which is probably more important and that is the crank triggers on the flywheel for ignition timing. If you have a flywheel can you check the pickups to see if they are really at 90 degrees. If they are not it may explain why changing ignition timing doesnt seem to have as much effect as you think it would.

[zippytlsr]

You did not have your chain tensioner released.

[zippytlsr]

Ok serious guess is that the Con rods were install facing apart and not facing together... according to the manual. There by allowing the crank to rotate the extra 3 degrees prior to the piston stopping at TDC. Yes?

hmmm, guess that's what doug said..