Blown Engine

[dave41]

we have run 15-1 compression and never squeezed the oil from between the bearings and rods. bull crap.

[dave41]

you can't turn 7600 rpm's with 20 degrees timing advance 35-36degrees for 7600 rpm's is about right. you have to advance to keep up with rpm or your timing will start to get behind your rpm's. 8200 you may have to go to 37 degrees

[FLYIN-9]

Thanks Dave!! They keep telling me the 2.5 is different because of the stroke. I'm real sure I don't have as much compression as you do. They keep telling me the bolts being loose was because of the heat caused by that cylinder pressure that streached them. I don't buy it. I think the bolts were loose causing the rods to beat the bearings out, causing the heat, that destroyed the engine. I'm no engineer by any means, but I don't buy their story. I just dont have any way to prove it.

[themotorshop]

i second the previus last 2 replies, from dave 41

[let-r-eat]

I've built enough 2.5 engines that ran MORE than 36 degrees timing with compression levels beyond where you are.

Excessive timing can take out bearings and low octane fuel for the CR can take out engines in about 4 laps. I'm not looking at the parts but I can tell you that 36 degrees isn't hurting a 2.5 engine. Period.

What took out your engine I do not know without pictures or something to go by. But you can bet your ass that it isn't from 36 degrees of timing.

[FLYIN-9]

I've gone over this several times with Race Engineering, & they keep telling me the same thing over & over about too much timing. I know how it was when I took it apart, LOOSE BOLTS!! They wont admit to it at all. They told me their machine shop insists they did nothing wrong. It all boils down to my word against theirs, & I loose.

[84Dave]

To all of you 4-cylinder engine folks............ for what it's worth. If you are using a 'dial-back' timing light on your engines, it could be junk! We checked ours way back when, and it was 8-degrees off, compared to a couple of no dial-backs which were spot on! Many Forums out there have been talking about dial-back lights that are anywhere from 4 to 16-degrees in error when setting the engine ignition timing! A large majority of them manufactured offshore. Particularly in China. Bottom line suggestion? Test your dial-back timing-light against a non-dial-back! -Dave-

[dave41]

how much kick back ,engine at operating temp ,did you have trying to start it. I always took timing a bit retarded and a touch fat on fuel. ran cooler. kick back is detonation

[FLYIN-9]

Hey Dave, it started right up. We've never had an issue with the kick back at 36 on any of our other engines .We s by ear to where the engine smoothed up, then finished with the timing lite. At that point it was dead on 34. We built our own again this time & going with how we always ran them. I'll find out Saturday night. I'll check the timing lite as well too

[car62]

ive run 38 degrees with a 5.7 rod 2.5 and never had an issue,ive also taken apart rods that the bearing was completely gone in and they were still proprly torqued, my guess is whoever assembled the bottom end had a bad day,and just overlooked something really important...did you call and talk to Rob Beagle?

[FLYIN-9]

Good morning "car 62". Yea, I've talked to Rob at Race Engineering, & he sent me to his tech dept. They all blame it on the timing, & nothing they did wrong. I know what I found when I took the engine apart, #1, & 2 rod bolts loose!!! My brother & I have been building & racing these engines for over 10 years, winning races & championships, & have a pretty good idea when something is wrong.