KMONEY306

rebuilding my 89 242's 454mag this winter. im trying to pick a cam. What I have is Dart iron eagle 308 heads, air gap intake, emi exhaust(wet) and scorpion 1.7 rockers. I want to avoid reversion at all cost. I am looking at a lunati hydraulic roller. 272/280 @.050 int 221/exh 229 lift .575/.575 112LSA. Anyone think this will cause me reversion. Ive heard some people say anything above exh .224 is too much and ive also heard don't go above .235 . Also anyone know the compression on a 89 454mag off the top of your head. Thanks

MILD THUNDER

iTrader: (3)

I believe the stock compression ratio was 8.6:1. Prob a tad less with the dart heads.

getrdunn

iTrader: (7)

I think your on the right track and personally do not see any issues with that cam and looks like a good choice. Ive run much reversion inviting cams than that with wet exhaust with no issues. A matter a fact my last 454 builds had the 502/465 hp cams and had no problems (236/246-553/571) I think. In fact I even used the 110 lsa. I think you'll be very pleased with your choice. Maybe while having your heads gone through have them take a little off your heads to get your chambers down to around 117 and run a thinner head gasket to help bump your comp a bit. Little closer to 9.0:1. Totally up to you. Do the math on compression calculator to be certain.

1989mach1

Where's Bob When you need him!!!!!!!





Oh BOB.......

picklenjim

A popular cam for something like your building is the Crane 139011 Retro hydraulic roller. (Mark 4 equivalent to the popular "731" cam)

Mr Maine

I assume the risers on the emi exhaust are longer than stock cast iron stuff? I agree, the 731 is a good cam, and I would run the gen vi with the retainer plate before running the gen iv with a button. Gen iv's have this provision because they made reverse rotaion engines. So much easier.

picklenjim

Good point. The Gen 6 cam with those specs is Crane 168731. You will need a gen 6 timing set to use with that also.

KMONEY306

thanks guys. Im running the emi with longer than factory risers. They dump more towards the transom