reaching 5500 rpm

[statey27]

Why would a 304 struggle to get to 5500 rpm. My mates vp feels like it has to really struggle to get to 5500 rpm and sounds like the engine is going to blow up. It feels like it looses power after 4800 - 4900.

[greenfoam]

Worn valve springs...? if it's making bad sounds?

[mouce]

Just because of the age of them most VN/VP (and I guess VG and VQ) motors start to sound a little asthmatic past about 4500. If they are in really good nick then 5500 isn't too hard, but if the valve springs are a little spongy then you get a lot air short circuiting the cylinders and it starves itself of air.

[jack.mc]

peak power is at 4400 according to www.holdenhistory.com

[trepaul]

it's an american/australian V8, what to you expect? if you want a V8 that can spin to 7500rpm get a supercar or a bmw

[Z()LTAN]

yeah its coz the pistons weigh like 500% of what the bmw ones do, think of the force on the trailing arms to bring it from TDC back down? lol and at 5000rpm that like 400G's lol

[greenfoam]

They are very stong motors, The 304 VN block has all the A9L stuff which is what the VL group A's ran around bathurst all day at 6000rpms with, it's also the same rods and block? pretty much the same as the L34 spec Torana and A9X, you can just about trace the history of the VN 304 right back to the Repco Brabham formula one. Forget your L34 heads, forget your A9X bathurst spec race motor, Forget the B cast Brock heads, the VN heads can flow up to 400hp straight from the factory, the potential is there . Lets not forget Larry Perkins winning Bathurst with the only (or one of a couple) Holden 304's in the First V supercar race at Bathurst. I still remember him being interviewed before the race and they were asking him why is he was running the Holden motor when everyone else was running full on Chev 302's and Ford Windsor 302's. Larry stood there grinding on a combustion chamber with his die grinder and said, it's a good motor you can do anything to it that you can do to a Chev. End result was that little 304 flogged two of Americas finest : )