MikeM

It's much easier and quicker to hook the vacuum advance from manifold vacuum, straight to the distributor and bypass the TCS to see if it will run properly with the timing set to factory specs. If it doesn't, map the timing curve, both mechanical and vacuum. That only takes a couple minutes. If the timing is to factory spec, THEN it's time to take the time to do a compression check.

Nobody on this side of the fence is throwing mud here. Just stating what is common knowledge to many, many people.

cardo0

U can't measure overcompression with measurintg timing - it won't fix anything either. If compression is too high and your retarding the timing to prevent detonation then your losing power and economy. U need to know what compression is highest.
I've driven cars with retarded timing before and i won't believe its any way to drive a car.
Just let him test the compression so we know what we are dealing with. Encourging him to retard the timing to live with overcompression is no good and i can't participate with that idea.

Good day,
cardo0

Mike Ward

This just gets stranger and stranger. WTF is 'over compression' and how would a dead bone stock engine suffer from it?

MikeM

I think your reading comphrehension skills are sadly lacking. Nobody said ANYTHING about backing the timing off to fix the OP's problem except you and LT whatever his name is. I did say to set the timing to factory specs and bypass the TCS for a much quicker/easier way of starting to trouble shoot his problem.

I'd never suggest retarding timing to satisfy the OP's problem and I'd also never suggest he lower the compression ratio in his engine to fix it either, unless somebody has been in there swapping out factory parts. Those LT1 engines run just fine in factory tune on 93 octane pump gas.

I'm also curious as to where you got this magic compression number?

Use your head and do the easy things first.

cardo0

No, u didn't say anything 'bout backing off the timing. Just something like set to factory specs. So what does that mean. U want to change the timing curve that the owner paid TISpecialty good money to do? Again change the timing curve done by a distributor specialty shop according to your over the internet instructions. I only hope the OP finds the sense to put u on his ignore list (i am). Like look at what the options really are. Leave timing curve as is - well its already detonating so thats a NO. Add more advance - well that would make the detonation worse = NO x 2. Retard the timing - well that will reduce the detonation but performance will suffer. No u didn't say retard the timing but i don't see what your other options are.

As far as the magic compression number i got it out of a David Vizard book - though the number i posted is a bit more concervative. U may not know who D. Vizard is but he has several publications on the sb Chevy and quite an expert. Normally i would provide a book name and page number to help a sincer individual but your comments 'bout my comprehension is nothing but a personal attack so u can read all the D Vizard books to find the information. I can tell u need all the advice. BTW did u expect to fix detonation no matter how high the compression/cylinder pressure? Yes u should use your head as u say yourself. I'm not a dyno expert either in fact i have never used a dyno but i can use the hard earned information of proffesionals written in books. Maybe u should start reading more than blogging away - before it breaks someones engine.

cardo0