92 with boost- Detonation issue- Boost GURU's inside please

[akfodysvn]

So I am looking to buy a car... have one all picked out very clean.

Car has a mild 347 which ran great according to owner. He then added a V1 to it pulling 8lb of boost. Car has 60lb injectors and a 340lph pump.

Owner took the car to get dyno tuned and he consistently had detonation issues regardless of the timing. I spoke w/ the tuner and said he had to put 0* of timing in the car due to the detonation which he never had to do before.

Fast forward and the owner states he realized he had stock heat range plugs in the car. He went 2 ranges colder which he believes to be the issue. So he calls the tuner to fix the timing in the tune. The tuner had his software stolen and all of his tunes stolen (I know for a fact this is true as it's a local tuner).

Car has not been re-tuned yet for the above mentioned reason. I guess I need to know if that's a legitimate cause or if there are other possible causes that I should be looking at? I really want to buy this car and am willing to take a little bit of a chance.

Thanks in advance!

Link to the owner's detonation thread:
http://forums.corral.net/forums/supe...y-pinging.html

[Mach1]

Can you post the timing map/table?
Does it run good at "0"?
Check tdc on damper vs true tdc

[akfodysvn]

Well I don't own the car yet so I can't do a few of those things.

The map/table was lost when the Tuner's software/laptop were stolen. It sounds crazy but I know for a fact it's true. For that reason there is no baseline available.

I believe there was still some detonation at 0*

[Mach1]

I'm curious as to what "0" means, is it "normal" out of boost and the whole table is zeroed out with positive manifold pressure?

[akfodysvn]

Could overall compression be the issue? I think its 9.5:1 but Woody from ford strokers mentioned it may be 10:1 or greater if it has flat top pistons and 58-60cc heads.

[91CoupeMike]

Could overall compression be the issue? I think its 9.5:1 but Woody from ford strokers mentioned it may be 10:1 or greater if it has flat top pistons and 58-60cc heads.

Not at those levels unless it has some shitty gas especially with aluminun heads.

[akfodysvn]

Here is a quote from the tuner... I got more info and am fearful there is a bigger problem underlying

The car came to me twice-
I tuned it on the dyno and upon finishing up the tune on the street it over heated and blew a freeze plug. Doug fixed all of that and said his car appeared to be "pinging" now. I had him bring the car back to me for me to go back over it. Going off of what he told me (he "FOR SURE set the timing with a light at 10 degrees advance"), I started pulling timing out to try to get it to stop pinging. After I had it all the way at "0" in the tune I decided to check the timing myself with the light. I found it to be at 28 degrees initial!! So I set it as where it was supposed to be, 10 degrees. Went back out to drive the car again, STILL had pinging at "0" degrees of timing.
-At this point I told him that FOR SURE there is some mechanical issue with the car. It should never have to run "0" degrees of timing, and STILL "ping"

It just seems to be hard to believe after finding out this info that it's just plugs...

[Sleeper]

Sounds like something i wouldnt touch unless you feel like having the motor done.

[akfodysvn]

I know what you mean. Part of me is just hopeful its simple...maybe even just a headgasket.

[91CoupeMike]

If the price is right, nothing $100 worth of gaskets and a few hours can't fix.

[akfodysvn]

yeah I just wish I was more knowledgable.

car has a b50 block, alum heads, 347 internal

3550 trans
Legit brake conversion kit from ford (cost around $2k new at the time)
full PPG paint
Plenty of parts worth some money.

We will see I guess...I may have asked too many questions and now I haven't heard back. I always think that a seller wouldn't mind serious car questions from a serious buyer. He knows very well how interested I actually am. Makes me wonder if I don't hear back if he's on the up and up. He already conveniently left out the "overheating" problem that I found out from the tuner.

[91CoupeMike]

You would think, but if they are trying to hide big issues as a plug change, then what a moron, imo. $20 worth of plugs and maybe an hours time in gapping and swapping them out. Shit... I would do it in front of him just to see if it fixed the issue.

[akfodysvn]

You would think, but if they are trying to hide big issues as a plug change, then what a moron, imo. $20 worth of plugs and maybe an hours time in gapping and swapping them out. Shit... I would do it in front of him just to see if it fixed the issue.

Plugs have been changed but it needs tuned. Current tune has all timing pulled out so there isnt any way to tell what its going to do once the timing is put back in it under boost. It may or may not detonate....

[jyro]

balancer outer ring slipped?