Is an Olds 350 close to an interference engine?

[Peter]

alright here is what i did.

I installed a new lunati cam just shy of .500 lift with an edelbrock timing set. Edelbrock has 3 key ways for the crank gear and three setups. I mistakenly installed the crank gear on the square keyway when it should have been the roundone for straight up timing (no idea why edelbrock decided this id figure the stock square should be straight up but i suppose i let an assumption get the best of me) Anyways i crossed the retarded or advanced timing up( not sure which way i ended up doing it) but the cam and crank were not in sync and i was wondering with dished pistons and a cam of that size would be even close to having to worry about my valves. I didnt hear anything strange when i cranked my engine, no tapping or knocking, just the odd exhaust tone because it wasnt going to fire up.

 

[CHRIS.O]

Well you should be perfectly fine. It isn't going to change the lift or anything like that. Advancing and retarding the gear is going to adjust at what point the valves open and how long. If you measured piston to valve clearance before you assembled the engine and you were fine you will still be fine. It would be nice to know if you retarded it or advanced it, both are entirely different especially if the cam already had an advance ground into it as some cams do. That is to say when you buy some cams and install them straight up they are actually advanced 4 degrees like if you advanced it with the crank gear. So if you advanced an already advanced cam to 8 degrees total you would be looking at an almost different camshaft.

 

[anakputa]

If you think you did any damage you could do a leak down test to be safe...I think the cam alignment on the cam and crank gear is "Dot to dot" or "Top to Top"...

 

[Peter]

Well you should be perfectly fine. It isn't going to change the lift or anything like that. Advancing and retarding the gear is going to adjust at what point the valves open and how long. If you measured piston to valve clearance before you assembled the engine and you were fine you will still be fine. It would be nice to know if you retarded it or advanced it, both are entirely different especially if the cam already had an advance ground into it as some cams do. That is to say when you buy some cams and install them straight up they are actually advanced 4 degrees like if you advanced it with the crank gear. So if you advanced an already advanced cam to 8 degrees total you would be looking at an almost different camshaft.

I may have worded it wrong. I lined the crank gear up on the crank as an advanced or retard position. And then when aligning the the cam to the crank used the straight up position on crank as my reference so I was mismatching the alignment. So im assuming it was totally haywire as far as the alingment. I am totally unsure of how close it might have been to being in sync with the pistons.

 

[DoubleV]

Are you saying you didn't degree your cam with a degree wheel? If so, that could be a huge performance killer. If you do not degree your cam, you will most likely be very sorry. Please do so, or you could be leaving huge amounts of power on the table. IMO, not degreeing a cam is the biggest reason why many rebuild/refurbished/modded engines seem to be such dogs. Low CR is the other...

 

[Peter]

Are you saying you didn't degree your cam with a degree wheel? If so, that could be a huge performance killer. If you do not degree your cam, you will most likely be very sorry. Please do so, or you could be leaving huge amounts of power on the table. IMO, not degreeing a cam is the biggest reason why many rebuild/refurbished/modded engines seem to be such dogs. Low CR is the other...

I bought the edelbrock double roller timing set that has 3 different positions to install it in. 0, 4 degrees retarded, and 4 degrees advance. I wanted to install it straight up but i criss crossed the timing by installing the crank gear in the retarded position but lining up the timing marks as straight up. So I believe my crank might be 120 degrees off where it needs to be. Tomorrow I am pulling the front accessories and timing cover to fix this.

This is a pic of it. you can see the three different crank keyways. What i did was installed it in on the square keyway because i assumed that was stock because the stock one was square. Then i lined the marks up as a straight up setup and that was obviously wrong. I should have read more of the instructions obviously. My question was essentially did i have the potential to damage my valves by doing this in an oldsmobile engine.