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timing chain gears

3K views 8 replies 6 participants last post by  Topkat 
#1 ·
My 400HO motor has the old single teeth gears on the cam and crank.
They seem to be in decent shape as does the chain,
The chain was rusty but cleaned up good.
Should I replace them with the more modern double roller chain
and gears?
Thanks again!
 
#4 ·
If it has the cam gear with the "plastic" teeth then yes, by all means replace the timing set. If it has metal gears on 'both ends' it depends on your budget and their condition. If you're rebuilding it yourself, do a trial fit with the new main bearings, crank, and cam after all the block machine work has been done. Use a degree wheel to find out how much 'slop' you have in the chain (how many crank degrees can you move the crank without moving the cam at all). If it's excessive, replace the set, but be aware that even a brand new set is going to stretch a little the first time you fire it up. If you want to be able to fine tune your cam timing by having the option of advancing/retarding the cam, then replace the set with one that provides that ability. I'm running one of these.

It's really tempting to buy "the best of everything" when you're building a motor and I'm certainly guilty of that myself. The smart way to do it though is to engineer it so that you select components that are matched to the power and load you're actually building for.

Bear
 
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