Re: Engine Rattle around 4k rpm, timing chain?
Posted: Wed Apr 19, 2023 10:51 am
Ya, that's pretty amazing. I have no idea what mine moved like, but the crank itself was ground down A LOT (I'll see if I can dig it out and take a pic).
Looking at the gears, two don't look too bad (crank gear and big jackshaft gear) and COULD be considered as runnable if funds are needed elsewhere, but the cam and inner jackshaft gears look too worn to me. You look for sharp teeth (the flat surface of the tooth wears until it's sharp) and undercutting where it rounds out the slot and creates a "Christmas tree" look to the tooth. Back in the day when the gears were rare and super expensive I took mine to Dann at Rallye and he told me what was OK and what wasn't, and I ran those gears for another 50k at least. Thanks to our great vendors we now have several high quality options with reasonable prices and individual gears can be bought. If you can replace all, great, but again I want to give as many options as possible and I don't think you would be risking anything by running those two gears. Better pics with the gear upright so we can see all the teeth might help make a final decision if in play. As always, get multiple opinions... I certainly don't know all!
That inner chain guide bolt head that's rounded off gives you an idea of how loose the cam chain was... I bet the Evil L was heavily damaged before it was cut off.
That engine was ready to explode. I know it sucks that you have discovered all of this, but the reality is the car would have likely failed in a spectacular way, and that would have been an unhappy and possibly dangerous day depending on the timing and circumstances, so consider yourself "lucky."
Looking at the gears, two don't look too bad (crank gear and big jackshaft gear) and COULD be considered as runnable if funds are needed elsewhere, but the cam and inner jackshaft gears look too worn to me. You look for sharp teeth (the flat surface of the tooth wears until it's sharp) and undercutting where it rounds out the slot and creates a "Christmas tree" look to the tooth. Back in the day when the gears were rare and super expensive I took mine to Dann at Rallye and he told me what was OK and what wasn't, and I ran those gears for another 50k at least. Thanks to our great vendors we now have several high quality options with reasonable prices and individual gears can be bought. If you can replace all, great, but again I want to give as many options as possible and I don't think you would be risking anything by running those two gears. Better pics with the gear upright so we can see all the teeth might help make a final decision if in play. As always, get multiple opinions... I certainly don't know all!
That inner chain guide bolt head that's rounded off gives you an idea of how loose the cam chain was... I bet the Evil L was heavily damaged before it was cut off.
That engine was ready to explode. I know it sucks that you have discovered all of this, but the reality is the car would have likely failed in a spectacular way, and that would have been an unhappy and possibly dangerous day depending on the timing and circumstances, so consider yourself "lucky."
Well... Maybe he dodged a bullet and the crank will be ok... maybe... gonna be interesting!