help!  I have put in 4 1.6L 8V used engines in a month!  I went and had a new one built(new pistons rings ect)  full rebuild and I'm having detonation (spelling ?)  I run prem fuel and my timing is set to 10 deg and 32 max.  I have a webber carb on it and  color of plugs are good.  I melted piston #3 down and when I pulled it all apart the other pistons were just as bad with burnt rings and blown head gasket.  I have a ping that is killing my engine.  I just had another engine built and I want to know what caused the last the blow so I dont have the same problem.  HELP!!!

Detonation is caused by too much heat and pressure in the compustion chamber. You said that you have an 8 valve with a carb right? Was the engine EFI before or was it always carbed? Are you running different heat range plugs? What is the stock timing supossed to be? If it was EFI did you swap in a different distributor? Answer with some more info and lets see what we can come up with.

Derek

Could also be a plugged exhaust system also. I had a bad muffler do that to a rig once but only three engines.

ok the head is a 1.3 and it has the 1.3  intake that had a pony carb when I first got it.  I changed the pony carb to a webber 32-38 3plus months ago.  it has had the 1.3 dis. Isky torquer cam and a DT header with new exhaust when I got it.  the first engine that came in my sammy ran good but after a year it was loosing compression(and I want to do the speed limmit  lol) so I want to replace it.  I tried band-aiding a few used ones to keep me going till I could aford to build a new one and have gone down hill since  lol.  picking up the second new engine in the morning and going to install it tomorrow.  I just dont want it to blow up again.  going to get the tail pipe sniffed to check if running rich or lean but the plugs are showing brown color and the 1.6 and the 1.3 are only one heat range different so I cant blame the plug since I ran the 1.6 plug for a year with out a problem.

I might be wrong, but that is what I've heard - this engines were designed to run on a regular fuel, not for premium. Premium fuel has higher octane in it which is causing higher detonation. I buddy of mine destroyed engine in Grand Am in one year filling up on premium...

I might be wrong, but that is what I've heard - this engines were designed to run on a regular fuel, not for premium. Premium fuel has higher octane in it which is causing higher detonation. I buddy of mine destroyed engine in Grand Am in one year filling up on premium...

I am pretty sure you are wrong on that.  Higher octane will generally cause an engine to ping less and run cooler.  Runnning premium fuel in an engine that is spec'd for regular fuel should not have any detremental effects on the engine (it justs costs you more money for the premium fuel).  Now running regular fuel in one that is spec'd for premium can cause some issues.




Over kill......you might have to play with the timing some more to get rid of the ping (although I think you have other issues other than the timing that is causing the ping).
Are the valves adjusted correctly?
Are you 100% sure you have the crank and cam timed correctly.  If you don't have the cam and crank timed correctly, but have the ignition timed correctly, it would be causing the valves to open either early or late and could cause some odd running behavior.....it would also throw your valve adjustments off.

I saw your post over on bc4x4. In your signature it says you are running a Crane ignition system, which system are you using? Did you get it running and get the emissions tested as well? Keep us updated.

Derek

If you mixed and matched head and block, you should check the compression ratio, especially if your machinist decked the cylinder block and head during the build. Detonation can also be caused by a too small combustion chamber volume, or incorrect shape in the chamber. Sounds like your trying to build a nice hot rod motor and if so you have many things to get right before it will work reliably.

Is your accelerator pump working correctly? you may be going lean under acceleration. Was the cam timing set with a degree disc? Have you checked the timing with a strobe to make sure that it advances correctly? With the 1.3 head on the 1.6 you are likely to be pulling more vacuum in the manifold so you may need to experiment with the dizzy to get the proper timing.

Premium fuel has higher octane in it which is causing higher detonation.

High octane levels in fuel raises the flashpoint. You can then achieve higher compression levels without predetonation.

I buddy of mine destroyed engine in Grand Am in one year filling up on premium...

No he didn't.