Lee-way

Not to burst anyones bubble but if I am reading what you are saying correctly you have a 7.4L motor. Just to for worn you that you may not want to spin that motor over 4900rpm's max because if you have this motor you have a cast crankshaft. It will not be a matter of if you will break it but, more so when you will break it.

tomas_wallin

I do know that it's a cast crank, and that the rods are perhaps not the best ones. Isn't it the rod bolts that break first, if you overrev the engine?

I still believe that it will easily stay together for around 420 hp. It is also going to be mounted in a rather light weighted boat - around 2200lb.

1BIGJIM

There has been alot of previous threads on cast cranks with many opinions. It seems the majority feel its fine up to 500hp. Do a search and see what you find.

TxHawk

Just as a price comparison, I have fresh 454ci with dyno time only. (Originally Merc HP425) Made 430hp on dyno. It includes all accesories, cooloers, plumbing, gil manifolds/ risers and transmission for $5000. This is a ready to drop in deal. When comparing that to a $3000 dollor upgrade that will be on a stock used bottom end, it seems there are better routes. My. 02$

I see that your location may not be great for performance marine v-8's

tomas_wallin

Just wondering (if you are talking about me) - why is my location not great for performance marine V8's?!

tomas_wallin

It seems that many of the boaters here on OSO has started out with 330's. Has there been any particular problems with hotting up them, that I should keep in mind?

The L-29 Vortech seems to be a fine pair of heads, or what do you guys say?

formula31

[QUOTE=tomas_wallin]It seems that many of the boaters here on OSO has started out with 330's. Has there been any particular problems with hotting up them, that I should keep in mind?

QUOTE]

Rod bolts, get the best ARP's, Blueprint bottom end (correct machining and balancing). Get the best components for the valve train, inconel exhaust valves, severe duty intakes, one piece 3/8" pushrods, stainless steel roller rockers, arp rocker studss, etc. Stay conservative on your cam choice. Set the quench around .040 and keep the compression close to 9-1 and off you go. Keep the oil temp under 250 at wot, may require bigger oil cooler and better oil plumbing. Have fun and good luck.

tomas_wallin

Yepp, I think I have understood the importance of quench so it is going to be around .040!

Is there some perticular oil that I should use?

Thanks!

dyno

do a search on "dyno's 330's on roids"I built them a couple years ago, new heads and exhaust bumped the compression to 9.5/1 rockers and some other add ons they made 505 hp at 5600 rpm.

tomas_wallin

I have already read the 330 on riods among many other threads. Most of them contains really interesting stuff!

I'm gonna read some more tonight, then I probably have some more Q's