HP gain from rebuild of 2.7

[Brent Lineker]

I have a 2.7 that developed a head leak on #4 cyl.The leakdown came back at 50% on that cylinder and less than %2 on all the others.The previous top end rebuild only has 30k's on it.I am planning on using Euro rs pistons 8.6-1 compression with e-grind cams.I already have 40ida-3c webers and ssi's and sport exhaust.How much of a gain should I see,will this raise my redline.I also have confirmed that no head studs have pulled but the raceware stud nuts did come loose.Any replies would be welcomed..

[Steve@Rennsport]

Brent,

Its difficult to speculate what you power increase might be without knowing the specifications of your current configuration, but such engines make around 200-205 HP if everything is right.

Your observation about loose head nuts with Raceware studs mirrors my own and the same goes for the ARP ones. These things simply do NOT expand & contract at the same rate as the engine does (as well as Dilavars), regardless what their respective manufacturers say.

All of our engines, save the 2.0-2.2-2.4 versions, get the late (993TT) Dilavars to help prevent stud pulling, loose heads, and gasket failures. Despite the issues with the earlier versions, Porsche really did get that right.

JMHO, so YMMV,

[Brent Lineker]

Thanks Steve.I will look at replacing with dilivar when we do the rebuild.Will my redline go up with the addition of the pc's and cams.Should I replace all the valves,springs,rockers ect even though they only were done 30ks ago.Thanks..Brent

[Eagledriver]

With "e" grind cams and stock valve springs your redline should be 7000 RPM. You can buy a rev-limiting rotor for your distributor that will cut out the spark at 7100.

-Andy

[Steve@Rennsport]

Brent,

Your springs, and valves should be just fine with 30K on them but I try to avoid using the old rockers whenever a cam change is done.

As Andy said, use the "E" rotor and you'll be just fine.

[Brent Lineker]

Thanks Guys,I will look at replacing rockers while we are at it,I may just go ahead and change out the valves too.I am hoping to not have to open up this motor again for another 75 or 100k anyways.