engine rebuild timing issue questions

[Big - D Racing]

I just rebuilt my engine for a higher compression piston and i'm in the process of putting my cam on and making sure the timing is where it is suppose to be at. The problem I have is I have one of Curtis Sparks 6 degree advance woodruff key installed and therefore the t ma on the flywheel will no longer align up like it does with the stockkey. How do I know where the ly wheel should be aligned to make sure my timing is correct with just 6 degrees advanced? Or do I have to put the stock one back inwhich I don't really want to do?

[PHIL_B54]

ive been pondering the same thing, and i thought i would open up the side cover loosen the bolt and rotate the flywheel back. it would then be back to stock. then i get done i will rock it back forward and tighten her back up. thats my plan unless someone else has one i like more

[a1965gt]

First you may want to call Sparks and ask them about using the key with a high compression/ larger bore piston. I am also in the process of a rebuild with a 11:1 416 Wiesco. I also have a Sparks advance key but when I talked to them they told me in no uncertian terms NOT to use it with high compression. I told them I would be running race gas and they still said not to use it.

If you still plan on running with the key I dont think it should throw off your timing marks much, or at least not to the point that if you installed the timing chain on the wrong tooth that that it wouldnt be visibly noticable.
When I dissassembled my cam/head assembly with the key installed i did notice that the marks on the cam sprocket did not line up perfectly with the head while at TDC however it was only off by maybe 1/32". Installing the chain on the wrong tooth would problaby result in closer to 1/4" misalignment at TDC

[trx400ex]

im pretty sure you want to leave the timing stock for the high comp.

[Big - D Racing]

already know it is not recomended because of heating issues, I have a fst oil cooler, oversized oil tank with cooling holes, a double wide Jagg oil cooler, air scoops, and I run leaded race fuel vp c-12 straight, so i'm not overly concerned with the heat issue.

[PHIL_B54]

i thought it was not recomended for "big bores" with high comp.
what about stock bore? i also have a fst style cooler.

if the heating did become an issue, what about only advancing it say 3 deg. only rotating it part way and tightening it?

Dont confuse advancing the cam with advancing the timing, it not the same.

The key causes the spark to advance and the cam will open the valves sooner, so they will create different problems.

I have not set up an engine with the advance key because I prefer to have a stronger bottom to mid hit and never saw the real advantage to one etc, so I dont know exactly what to advise you to do.

I wouldnt be too concerned about comp if your at the pistons rating or less (most likely less but that depends on other factors) but with the fuel mix being ignighted sooner in the stroke its allways a concern and you dont want to be burning any pistons.

Since you paid good money for that key I would be calling sparks to get their opinion before you hurt anything.

Good luck

[MIKE400EX]

Big D,
Instead of aligning the TDC timing mark, rotate the crank/flywheel mark about 5/16" past the case pointer. That'll put the flywheel at just about 6 deg. adv., so in turn the crank will be at "zero" and the piston at TDC. Now your cam alignment marks should be parallel to the head cover surface.

Originally posted by MIKE400EX
Big D,
Instead of aligning the TDC timing mark, rotate the crank/flywheel mark about 5/16" past the case pointer. That'll put the flywheel at just about 6 deg. adv., so in turn the crank will be at "zero" and the piston at TDC. Now your cam alignment marks should be parallel to the head cover surface.

Hey Mike, Good to see your still around. Been a while since I saw you post.

Hows the quad been running etc.

[Big - D Racing]

Mike that wasexactly whatI've been looking to hear.
Thanks a lot.