Need help with a blown 454..

[atunter316]

I recently had a rod knock start pretty badly on my 1991 rinker with a 454. Im tryin to get this up and going asap but cant decide on how to go about it. I was wondering if anyone could tell me if I can use an automotive chevy 454 or what would be a good rebuild kit for mine. I have a lot of experience with automotive engines but this will be my first marine engine pull and any help would be much appriciated. Thank you

 

[Silly Seville]

Re: Need help with a blown 454..

There are dozens (perhaps hundreds) of threads about this very topic. Search the site and its archives. You will be reading for days.

 

[tpenfield]

Re: Need help with a blown 454..

The 454 marine engine is basically the GM truck engine with a marine head gasket and a cam with less valve overlap, as well as brass core plugs. The ignition, electrical and fuel system components are marine to prevent fuel/fume hazard and open sparks.

If you can find a GM truck engine as a donor block, then you may be able to re-build it into a marine engine. I'm not sure if you could just repair the bad parts on the rotating assembly of the current block. . . You could just get a 454 short block for similar $$$$

 

[picklenjim]

Re: Need help with a blown 454..

Marine 454 is the same as ANY GM 454 block. Doesn't need to be a truck engine. However it does have all the fore mentioned changes made. You should have no problem repairing yours. Just pull the crank out and have it reground and have the rods resized. Have the cylinders checked to see if you could get by with a hone and re-ring, have a valve job done on the heads and put in a new cam-lifter-timing chain set and oil pump. Do the math on what this would cost and then see what a marine 454 long block goes for. Re-man marine 454 long blocks start at about 2K.

 

[OldNBold51]

Re: Need help with a blown 454..

Marine 454 is the same as ANY GM 454 block. Doesn't need to be a truck engine. However it does have all the fore mentioned changes made. You should have no problem repairing yours. Just pull the crank out and have it reground and have the rods resized. Have the cylinders checked to see if you could get by with a hone and re-ring, have a valve job done on the heads and put in a new cam-lifter-timing chain set and oil pump. Do the math on what this would cost and then see what a marine 454 long block goes for. Re-man marine 454 long blocks start at about 2K.

+1 on this advice. I was surprised at how out of round the big end of my rods were. 4 of the 8 were out of spec. My rebuild with machining was around $800. My piston/bore were in spec so i avoided that cost. I got away with rings, bearings, gaskets and machining.

While your at it you may want to investigate upping the compression a bit. Upping from 8:1 to 9.5:1 sure helped my holeshot. I only had to up the gas octane to 89 to compensate.