Will my DCR be too high?
Will my DCR be too high? I've got a set of milled 241's ready to go on my stock ls1 shortblock. Will be keeping the stock cam. Am i going to be able to safely run pump gas (92-93 octane) on this setup? Heads are milled to 59cc which is about 0.045 if im not mistaken. SCR would be right around 11.5:1 which im a little hesitant about.
I'm fine with running a thicker gasket if i have to, just looking for some insight/opinions
I'm fine with running a thicker gasket if i have to, just looking for some insight/opinions
A thicker head gasket is a terrible way to lower compression. A tight quench area and a little higher compression is usually more detonation friendly. Colder plugs will help a little too. What elevation are you driving it at? Sound like your pushing it but I dont know what stock cam you have. Sound like a good time to upgrade to a little bigger cam. You might double check that compression ratio also, Im not sure but 11.5 sounds with a 59cc sounds a little high to me.
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From: PA/MD
If everything else is stock, .045" milled off of the 243's will be fine and should put you closer to 10.7-11:1 scr.
Like said above run a .040" head gasket (I prefer mls) to get your quench right at .035" to help with detonation
Like said above run a .040" head gasket (I prefer mls) to get your quench right at .035" to help with detonation
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From: BFE
A stock motor with 57cc and standard gasket is like 11.75:1
His motor with milled 241s will be around 11.4x:1, so use standard gasket, you'll be fine on 93 octane.
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From: PA/MD
The 241's start out at 67cc don't they?
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it is easy to check the chamber cc's. Buy a syringe from a feed store or vet. get a small piece of plexi glass to put over the chamber and drill a small hole in it on the far side. if you drill it in the middle it is harder to get the air bubble out. line it with a light film of grease and see how many cc's of water it takes to fill it up. I would definetly want to stay under 11:1 with a stock cam at sea level. You may have to change the pistons or heads to get it right. Most people shoot for a quench of about .040 for safety.
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