who has the highest CR on 60*?

[01GPGT]

actualy deisles run on "knock" they have no spark to ignight the fuel only heat witch is what knock or ping is in a gas engine. A hot spot ignites the fuel befor or after the spark plug fires. it is the two flam fronts coliding and making a shock wave that damages the pistons and barrings.

I can also see gas in a deisle cousing that kind of damage becuase gas has more energy potential then deisle fuel does


or at least thats what my grandpa described it as when i asked him and he has never had any formal training he just read books and figured it out the hard way since the 1950's lol

[torq455]

diesels don't resist knock. they are built heavy to take it. that's why they are so noisy.

[pocket-rocket]

Wanna know what 32:1 would do in a car? Put gas in a diesel truck lol. A guy I knew said he worked at a place that had multiple trucks, a few being diesel. One day a kid that didn't know better (read "anything") went to fill one of the diesels up. Guess what he put in it? That's right, good ol' unleaded. Wanna know what happened? After the big explosion sound I guess pieces of the engine were heard bouncing between the floor pan and the road as the truck coasted to a stop. Luckily if you put diesel in your car you won't go anywhere until you get your tank and fuel system drained and get gas put back in it.

http://en.wikipedia.org/wiki/Diesel_engine

[Ghettoracer]

semis do that on a regular basis...

diesel's ability to resist knock is awesome

Defiantely, all heat and no spark, I still quite haven't gotten down how diesels work like that tho LOL I know CRs on diesels are quite high and so little maintenance to be done to them. No but try to put 36:1 CR into a car would be ridiculous.

[robertisaar]

I'm running on 36.2:1 CR LOL Not really but that would be a bad ass CR. LOL

semis do that on a regular basis...

diesel's ability to resist knock is awesome

[Ghettoracer]

I'm running on 36.2:1 CR LOL Not really but that would be a bad ass CR. LOL

[robertisaar]

since ~14.7PSI would double your compression:

8/14.7=.544

so (.544 + 1) * 9.6 = 14.8

[AaronGTR]

yeah, he has a double roller now, new bearings, 2 engine fires now taken care of, and still no video or anything. Im giving serious consideration to a florida trip this winter.

If you do, we should all get together. He's only about 40min from me.

true dat-whats the highest cr anyone is running with boost at this time? anyone know of anyone pushing 11:1+? i find it unlikely but with low boost you never know, it doesnt hurt to ask-maybe itll make somebody come outta the woodwork with something quite nasty...

Well I'm running stock 9.6:1 with 8psi. I have no idea what effective CR that works out to though. Anyone know where there's a good calculator for that? i couldn't find one.

[Azrael]

There was someone in Ontario with an 80's S10 with a fbody 3.4 and an M90 running on pure propane. Had something like 11:1 CR with 15 lbs of boost on top of it. With the energy density of propane it wouldn't have been as powerful as with gas but still nothing to laugh at. There's a thread about it somewhere with videos.

[ForcedFirebird]

My motor is 11.56:1, but it's not done and considering using the 3400 pistons instead. Effective CR with 9.1:1 SCR and 15psi is about 18:1, same as a motor with 11:1 and 4psi.

[no_doz]

sounds like most of the guys building anything serious.

We are going to trash some bearings to get the CR we want, but when you look at 12psi that has been done a few times, calc it out and your are talking about 18+:1 CR. Pump gas.

true dat-whats the highest cr anyone is running with boost at this time? anyone know of anyone pushing 11:1+? i find it unlikely but with low boost you never know, it doesnt hurt to ask-maybe itll make somebody come outta the woodwork with something quite nasty...

[SappySE107]

yeah, he has a double roller now, new bearings, 2 engine fires now taken care of, and still no video or anything. Im giving serious consideration to a florida trip this winter.

[ForcedFirebird]

I've seen his car once. He was on the florida gm forums and he contacted me to help him tune it. When I went over though he was having MAF and MAP issues and he ended up having a couple injectors that weren't firing too. Car would start but needed throttle to stay running and ran terrible. Some stuff was wired up wrong and last I heard he fixed them and the car would then stay running, but he never contacted me to come back and re-tune it. Haven't heard from him since and no idea if the car is still running or not.

I could tell even running poorly though that it was gonna be a mean engine!

sounds like most of the guys building anything serious.

We are going to trash some bearings to get the CR we want, but when you look at 12psi that has been done a few times, calc it out and your are talking about 18+:1 CR. Pump gas.

[AaronGTR]

Eric in florida has 12.4:1. 3.4 DOHC pistons .040" over and 3500 heads. Premium pump gas is what he is running on. I have no video or anything and he never posts anywhere so its a complete mystery to me other than it runs.

I've seen his car once. He was on the florida gm forums and he contacted me to help him tune it. When I went over though he was having MAF and MAP issues and he ended up having a couple injectors that weren't firing too. Car would start but needed throttle to stay running and ran terrible. Some stuff was wired up wrong and last I heard he fixed them and the car would then stay running, but he never contacted me to come back and re-tune it. Haven't heard from him since and no idea if the car is still running or not.

I could tell even running poorly though that it was gonna be a mean engine!

[pocket-rocket]

Didn't Taylor (3100MPFI) have over 12:1 on his?