smiklos@sunprint

iTrader: (1)

OK guys I need help!
I have a good friend has a 35 Cafe with hawk 525's I just helped him convert from TRS to Bravo's stainless marine dry exhaust and Imco boxes so of course it blew an engine. Divorce just came quickly to town for him. So I want to help him out but not spend too much (it will be my money at least for now or forever) Engines have 385 hours and one dropped a valve. I am trying to stay on a budget, but that seldom works!
A few questions.
Stay on flat tappet hydraulic cams?
Really cheap have been fine.
He does idle for long times (30 minutes) so that is why the flat tappets scare me.

Just do top end of existing engine?

Is it a good idea to go after low end cast stroker rotating assemblies (496) like scat at around $1100?

I really want to use to RM builder cam packages and 4340 rotating assemblies but he has no money and unlike many who say this he really does not run his boat hard (we went 70 and he was freaking out).

All thoughts proverbs etc accepted with an open mind.
Thanks!
Steve

wannabe

Having older 454's like your buddy does I rebuilt my uppers on my engines by going to roller cams, new Dart Iron eagle heads and retuned the engines. I caught mine just before the exhaust valve tuliped on my starboard engine.

The heads (all 4) have to be rebuilt totally on the HAWKS, the old Chevy HI PO heads which you probably have are prone to dropping valves. So either R & R or replace them.

As long as the cams are in good shape keep them, but do an inspection. I would put all new springs and valves in the heads.

Thats the cheapest he is going to get by.

Wannabe

Unlimited jd

iTrader: (5)

Better tear down and see the complete extent of the damage. I would not increase cu in of the motors or try for anymore power if you're going to keep the 174 blowers. They create too much heat as I've found out the hardway. They work great if the engine built with tolerances to handle the heat. But not so good if the motor is built tight as mine was.

picklenjim

Most of the time when you drop a valve it cracks the cylinder wall or at the least damages it bad. Also beats the crap out of the combustion chamber in the head. Don't see you getting by with just doing a top end job. Need to be sure it has Inconel exhaust valves or equivalent, assuming it was an exhaust valve. Most important you need to figure out why it dropped a valve or you may be fixing it again. Usually a lean condition.

smiklos@sunprint

iTrader: (1)

I was planning on doing the entire blown up engine (have a block and heads) Minimum would be new pistons valves and springs. I am hoping to just do top end of other engine (still running) new valves and springs (check for cracks). Once you look at you need to size rods and get bolts you want to buy rods than it grows from there!
Thanks
Steve

MILD THUNDER

iTrader: (3)

Id do a leakdown test on the good engine. If all is within spec, maybe some valve springs and run it. As for the broken engine, repair and replace only whats necessary. No point in sinking a ton of money in the old 525 hawks, as the blocks at this point may be compromised from corrosion, and full rebuilds with roller conversions, pistons, rods,machining, etc will put you close to what a new set of bigger CI engines NEW may cost.

Id be worried about the bravos in a 35 cafe with 525HP per side. Go easy on them. I personally would have left the TRS on, but that's another thread...