Jesel timing belt

[Jim Johnston/6022]

I had the same issue a couple of years ago. Called Jesel and they said block must have been align honed and i could order a shorter belt. The fact i tried 2 different old belts and an old complete comp.cam belt system and they all happened to be tight did not change his mind. I put it together with it being a couple of degrees weird and it has been ok and no drama.
Jim & Ken Johnston GT/QA

[Ed McLawhorn Jr.]

Originally Posted by Jim Johnston/6022

I had the same issue a couple of years ago. Called Jesel and they said block must have been align honed and i could order a shorter belt. The fact i tried 2 different old belts and an old complete comp.cam belt system and they all happened to be tight did not change his mind. I put it together with it being a couple of degrees weird and it has been ok and no drama.
Jim & Ken Johnston GT/QA

Exactly Jim, I don't believe a shorter belt is the answer. The belt is tight, but sliding in cam gear groove between the cam gear teeth and only became evident with spring pressure.

[BillK]

Ed,
I have seen this several times on modern street engines and every time it has been the belt made improperly and a different brand belt fixed the problem. I know in your case you are stuck with Jesel for the belt but I think at the very least I would ask them to send you another belt and see if the teeth are made correctly. I sure as heck would not want to run it if the belt does not properly match the sprocket.

Just my opinion

[SBillinson]

There may be a gauge available to check the pitch and other dimensions, similar to a thread gauge.

You could instead make a template out of aluminum to fit the gear and then compare it to your belt. Take a photo and send it to Jesel if the two don't seat correctly.

Easier still would be to take a photo of the top gear with the belt on.

Most Jesel belt drives don't have an idler. I've never understood why. I imagine the belt would stretch or create slack between the leading and trailing sides, especially with a lot of spring pressure. Has your spring pressure changed significantly?

[Ed McLawhorn Jr.]

Originally Posted by SBillinson

Has your spring pressure changed significantly?

Not really...I did move seat pressure up 15lbs, but not enough to cause this issue. Thanks.

[57 Vette]

This is one of the many reasons I had Alan at SDPC Race Shop install a Milodon Gear Drive System on my 582 Head Hunter engine. I would never put a rubber band on any engine I own. I have been running gear drives on all of my engines since 1975.

[Ed McLawhorn Jr.]

Originally Posted by BillK

Ed,
I have seen this several times on modern street engines and every time it has been the belt made improperly and a different brand belt fixed the problem. I know in your case you are stuck with Jesel for the belt but I think at the very least I would ask them to send you another belt and see if the teeth are made correctly. I sure as heck would not want to run it if the belt does not properly match the sprocket.

Just my opinion

Thanks Bill. As a follow up, I called jesel yesterday and the tech guy told me that 2-4 degrees was accepted and expected. Not sure I still like it. I called a friend who builds motors for a living and he told me he had been seeing this for some time. I don't believe another new belt will be better. He just keep the belt up against cam gear in correct rotation for cam degree.