Carbon Footprint

iTrader: (4)

Okay, so latest boat acquisition is this:
1991 Wellcraft nova 26 st with twin 454/bravo and 340ish hours.
The boat was sold to me with water in the engines....unknown damage, at a fairly good price. I just finished tearing both motors down and they are ready to go to the machine shop as early as tomorrow.
Port Engine looks to be original other than the L 2377 flat top pistons that are .030? Did mercruiser use these stock? The crank is .010 with clevite 77 bearings and the cam is unknown only marks are 31220?1 Two bolt main blocks stamped 14015445 T14 and Hi perf on the end. The heads on this engine are square port 360 peanuts that look original.

Stbd Engine looks to be freshly rebuilt, everything the same as port enigne except cam is marked MAP K. The heads on this one are 049 large chamber oval port with newer springs.

I picked up a builder set of 049 heads to replace the peanut port on the stock engine and I am trying to figure out what cam to use to make the motors match.
Assuming I don't have to bore and get new pistons, (or even if I do) what would your recommendations be for putting these back together on a budget, but also the best bang for the buck while they are apart.
I am not looking for 500hp. just solid performing motors that will last a while and perform decently. Maybe like to see close to 400hp and 5200-5400rpm?
The intakes are both edelbrock performer 2.0 and Q-jet 4bbl carbs.
Looking for cam suggestions, what type of headwork with stock exhaust (will replace but not this year) if I do have to bore, should I replace pistons with something different to up the CR, as I think the setup as mentioned will only be 8:1 or so (great for blowers

Your input and advise are appreciated as always!

BillK

So that engine has obviously been rebuilt in the past.



No such animal, they are either square port (rectangular actually) or Peanut port which is a very small oval port

Stbd Engine looks to be freshly rebuilt, everything the same as port enigne except cam is marked MAP K. The heads on this one are 049 large chamber oval port with newer springs.

Your machine shop might be able to figure out what the cams are. I can try to check the number in a few catalogs on Tuesday. As far as replacing them goes, personally I would call my cam manufacturer of choice and ask them for a recommendation. You need to know every possible detail about the engines, drives, props, and the boat.

Personally I think you are going to have a hard time getting a true 400 horsepower without upping the compression and doing some head work.

Just my opinion,

Bill Koustenis
Advanced Automotive Machine
Waldorf Md

picklenjim

If you are wanting to keep the budget down and stay with the stock exhaust for now I would just have a three angle valve job done on the heads and put in mild flat tappet hydraulic cams something like this.
http://www.summitracing.com/parts/CCA-11-306-4/
Probably not going to see those RPM's unless you prop it to spin that high. 48-5000 would be more realistic. Exhaut will be a big factor if you want to really start getting into it.

Carbon Footprint

iTrader: (4)

Dropped off blocks heads and crank this afternoon at the machine shop, and unfortunately he doesn't think the cylinders will clean up with just a hone Why don't people pickle the motors after they get water in them!
So since I have to go .060 and get new pistons and cams anyway, what are your recommendations for pistons and cam on these 454s?

Again using 049 heads 122cc? I would love to up the CR since I have to get new pistons......... what is the safe limit on 87-91 pump gas?

picklenjim

You might be able to go with something like this to up compression a little. Small domes designed for use with closed chamber heads. This will give you less of a jump beings you have open chamber heads. I think to be safe with iron heads you need to stay in the lower 9's max.
http://www.summitracing.com/parts/UEM-KB203-060/