who has the highest CR on 60*?

[robertisaar]

since ~14.7PSI would double your compression:

8/14.7=.544

so (.544 + 1) * 9.6 = 14.8

[Ghettoracer]

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

[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]

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.

[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

[torq455]

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

[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

[ForcedFirebird]

The quad turbo semi's that are built to do the tractor pulls are running about 100psi, on top of the 16 or 18:1 compression. They are running SO much boost that they are constantly on the threshold of hydro-locking the engine because they need that much fuel to compensate all the air going in and maintain a 12.5:1 AFR. Air compresses, liquid fuel doesn't

[robertisaar]

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

i guess i should rephrase that:

diesel's ability to not blow the fuck up into 5000 different pieces due to knock is awesome.

[MMGT1]

Mine was pretty strange. When the block was replaced a couple of weeks ago, Milzy tested it before the install and we got 180 arcoss all cyclinders. Tested it again last week and got 205-210 straight across(1500kms on build). I have no idea how to convert that, anyone know what I'd be sitting at?..... curious

[ForcedFirebird]

Cranking pressure doesn't always relate directly to static compression.

[MMGT1]

Would that give us an estimate? Figure Im around 10.5 or so right now, but I really dont know.

[ssdurango]

Hey I'm the guy with the propane 3.4. I had It at 11:1 with 12 psi boost running straight propane. A ring land broke on the dyno, could of just been a weak casting. So I've been running around at 9:1 at 12 psi this summer.

I'm also a diesel mechanic. The knock in diesels is due to late or early combustion on the power stroke caused by low ambient tempurature or poor injection timing.

[geoffinbc]

Diesels don't knock, or detonate. Fuel is not in the cylinder until the very last part of the compression stroke. No engine can withstand constant detonation. Think of the diesel injector like a spark plug. It will inject fuel several degrees before TDC just like a spark plug sparks before TDC. But never so much that the pressure causes detonation. Remember fuel takes time to burn so you must initiate a flame before TDC so when you do reach TDC the full burn is on and real power can be made. This is why Direct Injection gas engine have the ability to run boost coupled with very high compression. There is no fuel in the cylinder until the very end of the compression stroke. So there is no risk of fuel burning early and essentially trying to run the engine backwards.

[sprucegagt]

The quad turbo semi's that are built to do the tractor pulls are running about 100psi, on top of the 16 or 18:1 compression. They are running SO much boost that they are constantly on the threshold of hydro-locking the engine because they need that much fuel to compensate all the air going in and maintain a 12.5:1 AFR. Air compresses, liquid fuel doesn't

No offense, but their is a little mis-information here. Those semi's can be multiple or usually single turbo, but either way run over 100+ PSI. There big hold up is getting enough fuel (injection pump limitations) or running too much boost for the block. The block will split length wise at the cam bore. Hydrolock is much more likely in a Top Fuel Nitro dragster.