Thread: BBC 468 Build questions

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Why do you say that? Are you zero decked and do you have your heads milled or what?
Clay

I would leave it around 9.5 to 1 with that camshaft. You will have lots cylinder pressure with that camshaft timing and 10 to 1 compression. You may need to consider higher octane fuel. I like the 781's...good heads, usually about 119cc.

you might consider going with a slightly smaller cam, maybe around .510 or .520 lift, keep your compression ration you come up with. seems a bit overkill if your not revving over 5500, plus you want torque torque torque, down low in the powerband if your going off-roading. I'm assuming thats what you'll be doing with your jeep aside from daily driving. Comp has an Extreme Energy 4x4 series that has a cam perfect for you, Hydraulic-Great mid-range power, largest cam for stock converter. Good for heavy towing with 4.10 gear. 218/226 duration .505/.515 lift. Probably has a decent idle too. But that my two cents. I'm building almost the same motor, but its going in a street driven 84' shortwide Chevy that will see some track time. I'm milling and decking but i'm stuck with flat tops so I have to, just to hit 9:1. My block is a 4 bolt, with 781's, 2.19/1.88 valves, Edelbrock 2.0 manifold and a Demon 800 double pumper. I still can't decide on the cam but probably no more than .550 lift, should be a nasty little torque pig with lots of grunt, good luck with your build

Trust me I know about down low torque for off-roading. But it is all relative, since I come from a "mild" SBC in my last CJ-7. As much gearing as I have I am rarely below about 1000rpm. I am running a 3.77 1st gear, 4:1 low in the t-case, and 4.56's in the axles as of now. I will be running a 6.32 1st gear, 4:1 low, and 5.89's by the time summer is out. After talking to my machinist, I am probably going to just have them square up the heads and block and call it a day. He say that with those pistons and how my motor looks now I will be at 9.66:1 just squaring it all up. I was told to get as close to 10.5:1 to get the most out of the propane, and then just back the timing out to get it to burn premium on the street. That is the only reason I was looking for more. I do not mind having to run high octane fuel, I did it for 4 years with my CJ-7 as the SBC in it was at about 11.5:1. As for daily driving... it gets taken on the road on nice days around town and to the lake. Anywhere else it typically gets put on a trailer due to the gearing.
Anything else I should think about?
Thanks again for your time,
Clay

Here is a few photos from the last time it got bashed on...