blown

Hey motor gurus, got a question for ya. The stock 454's (420 hp) in the ol' cig were rebuilt to a high performance spec with blowers back in 2001, which was about 200 hours ago. Back then she'd hit 79 on GPS. The motors still run great and have been very reliable all season, but nowadays she tops out in the lowish 70's. I just winterized her so can't do a compression check until the spring, but I'm wondering if i can expect to get some of the lost power back after a top end refresh? I suppose a greater priority is reliability, so more importantly would a refresh extend the life of these motors over continuing to (more or less) gas, oil, and go?

mike tkach

iTrader: (3)

with 200 hrs i believe a valve job&new valve springs will restore your power.now would be the time to do it so you will be good come spring.

MILD THUNDER

iTrader: (3)

I agree with mike. Minimum top end refresh. Also, what blowers? Theres a good chance the blowers may be tired and down on boost and need of a rebuild also

offshorexcursion

iTrader: (5)

Spend a little now or gamble and maybe spend a lot more later when something breaks/wears out.

28Eliminator

I agree with all of the above. A valve job, new springs, guides if needed, and you get a chance to check/replace rockers and lifters if questionable. After 13 years, it owes you nothing. It's very possible you have a broken spring, or some that are weak, and depending on head gaskets used they could be ready to go. You could do a leak down test now, but being down 5-7mph, you know it needs attention before major damage occurs.

MILD THUNDER

iTrader: (3)

Blowers are likely tired. The 174 was a teflon stripped tiny blower. Spinning at high rpm like they do, i wouldnt be surprised if the stripping is worn out, and youve lost a decent amount of boost. Have you?

blown

They are B&M 174's.

Also spoke to Dave at MDG (who did the build) today. He had the motors out last year to replace the steering cable, thought it was running quite well and wasn't in dire need of a refresh. I definitely want to do the top end, but can't this winter. He'd want it as an off season project so I'm thinking after next summer would be good timing. I'll take it easy till then (i baby her anyways, only ran once at WOT all summer, I'm probably an outlier here on OSO!)

Thanks for the input guys.

blown

how would i know if I'm down on boost? wouldn't be surprised if thats the case, it explains why the motors run well but power is down. did a quick search and i see they can be rebuilt here: http://www.superchargerusa.com/b&m.htm