High comp
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High comp
alright, well i searched and couldnt find exactly what i was looking for. so here it goes, how does a high compression engine react to towing? I some how acquired two 4.7 long blocks for free (i seriously dont know how). anyway, i have a some spare time and a little spare money and am thinking about building a high comp engine to put in my 02 qc 4.7. I was looking at the krc web site and they have 11:1 which is a little higher than i would like but i can order almost any comp i want. how would a 10.5:1 react to towing? any input would be amazing. thanks again
Adam
Adam
RE: High comp
sounds like you are right at the top of the capability to run on premium pump gas. It may also cause your timing (computer controlled) to retard some. As far as the towing in and of itself, You may actually run better, if you can get it tuned in to the gas and compression
issues.
You may actually be better off to rebuild the new engine to current specs, only use a slightly different piston build. Or better yet, build a stroker engine, and add a supercharger or turbocharging. You just really have to consider the current piston arrangement with the "thin" top ring land. If you would have a new set of pistons cut with a thicker top ring land, possibly moving them down, you could probably build some serious power. Unfortunately, or fortunately--depending on how you look at it, you will also have to go with a piggyback ECU also to override the stock tuning configuration.
You might try shooting https://dodgeforum.com/showProfile.asp?memid=14944 Avanti a PM and passing some ideas past him. He may be able to help develop a plan of attack. He has many years of experience with High Performance mods and may be able to give you some pointers.
issues.
You may actually be better off to rebuild the new engine to current specs, only use a slightly different piston build. Or better yet, build a stroker engine, and add a supercharger or turbocharging. You just really have to consider the current piston arrangement with the "thin" top ring land. If you would have a new set of pistons cut with a thicker top ring land, possibly moving them down, you could probably build some serious power. Unfortunately, or fortunately--depending on how you look at it, you will also have to go with a piggyback ECU also to override the stock tuning configuration.
You might try shooting https://dodgeforum.com/showProfile.asp?memid=14944 Avanti a PM and passing some ideas past him. He may be able to help develop a plan of attack. He has many years of experience with High Performance mods and may be able to give you some pointers.
RE: High comp
high compression and towing generally don't get a long well in a gas engine. With our pcm, you'll get knock retard which means the pcm will pull timing giving you less power. If you can run some 100 octane you'll be fine.
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Joined: Apr 2006
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RE: High comp
well, as far as the tuning, im not too concerned, i have a tecIII laying around as well as a megatune (both are standalones). the pistons from krc have the thicker and lower top ring which is what gave me the idea of high comp. ideally i wouldnt mind just the jeep HO 4.7 pistons (they are 9.7:1). Any further ideas would be great. thanks
