2.7 mix and max your thoughts??

[burtm5]

I'm in the process of making one engine out of two and have some questions. the 2.5 (2.2 T crank with 2.7 8.5 comp. euro pistons) webers, e-cams, ssi, has bent a couple valves and broken rocker arms and 75 k miles.(yes it was the $ shift) the second is a 75 2.7 CIS. with euro pistons and cylinders rebuilt within 500 miles, then wreaked and removed. I assumed that the new to me 2.7 had 8.5 euro rs pistons but when the cis cams were taken out, the e cams won't fit. So it appears that the cylinders are cis type with perhaps 9.0 or more Comp. Before this problem,and assuming 8.5 euro pistons, I was going to put 40 webers, e cams, ssi, gutted muff. 35 mm intakes, 35mm heads on the 2.7 motor and into a 71 T. Questions, has anybody put carbs on cis pistons? Has anybody eyebrowed the cis pistons to allow more lift cams?? (seems like a bad idea btw). Would YOU put 75 k euro rs pistons (run hard and put up wet) into an otherwise new rebuild? Or Should I do what I wanna do and just bite the bullet and throw away the 9.0 cis pistons and put in new 9.5 je pistons. The heads are to come off soon to be sure of what I've got.

[Eagledriver]

Carbs work fine with CIS pistons. You can cut valve relief into the CIS pistons. Your machine shop should be able to tell you how thick the piston tops are and how much they can cut. I would measure the euro pistons to decide if I should use them. There are wear limit numbers you can follow to check used parts.

-Andy

[unclebilly]

I am running 9.5 JEs shimmed to 9.8 in my 2.7. I am using DC40 cams, I opened up my intake ports to 36mm, and have 40mm webers with 34mm venturis and a RS curved dist with MSD.

On 6 month old fuel, and last years plugs and a Dyno Dynamics dyno (stingy) the engine HP backed out to 236HP. I can't remember what it was at the wheels. this engine has a fairly flat torque curve and has been run hard at he track for 3 seasons. Max power is about 6500 RPM. I am running a S rotor so it revs to 7300+.

[burtm5]

unclebilly, thanks for putting up some hp numbers I was hoping for such info. your cams are similiar to S if I'm reading DCs site correctly although overlap on the dc 40s are same as my E? I will see how much has to be taken out of the cis pistons and try to figure how much cr is ultimately left. for street and DE I was worried that S cam was too much, E was too little and solex was just right. I was curious as to what hp gains are for each increase, ie 20 hp for each point in compresion, aprox 20 hp for each increase for Cam, from T to E to solex to S other things being the same? If I get 9.0 cr with my set up I"ve basically got a 2.7 L hopefully 220 hp. best Henry

[larrym]

do what you wanna do

sounds like you have the cash to do it right