i am looking into building a new motor for my boat, i already have a gen 6 454 in the boat with oval port heads, dual plane air gap intake, crane 732 cam, gils with hp500 pipes, crane igntion, holley 750, large oil cooler, oil thermostat, roller rockers.... would like to reuse as much as possible. i have been looking into finding a gen 6 454 block and throwing a stroker kit in it, is this gonna end up being worth it verses using a 502 as a base? i can find the 454 blocks for reasonable prices but not a 502. for the cost of a 502 short block used i can get a 454 and the stroker kit for it and then just add machine costs to it.

if i were to use my existing block, it started as a 454 330hp motor and has everything above added, would it be worth the cash to throw a set of mag heads and a rec port intake on there?

i am on a limited budget but since i do most everything besides machine work on my own and i have the exisitng setup i think i can build something decent.

if someone has a engine build they built with like a ebay stroker kit or similar that they did cheap and worked out to have good power i would love to hear it

also, am i gaining much by using a gen 6 verses a gen 4 block?

my questions may seem all over the place, probably because they are but i would like to find a direction in the next step to take on the boat motor. thanks!

A freind of mine built 489cid (stroked 454s) with edel oval heads, air gap and nickerson carbs and the 731 crane cam. He made 617hp on the dyno with 9:1 compression. I'd do the same but bump the compression up to 9.5:1 or so.

I remember when you built the engine you have now. It is pretty well matched for what you have. A forged stroker kit would get you more CI and more HP. I have thought about building a 540 and swapping over most of the parts from the existing engine. Problem is Large Ovals may not flow enough for the 540, most guys use GM rec port heads or aftermarket. I would also have to get a bigger cam and pistons. Or you could leave it alone.

honestly i should be leaving it alone but what fun is in that? lol. this may be a 2 year build, i am in no hurry but i want to start getting something in the 600-650hp range. this is what i get for hanging around people with faster boats lol. if i were to do a stroker short block with the existing parts are the heads gonna hold me back that much? they are the L29 oval ports, said to be great heads...

I am running about 500HP, I have forged 489, RMbuilder cam, Holley MPI, Large Oval 820's, EMI exhaust. You are probably in the 450 HP range. Do you still have the stock cast internals? I have also thought about a couple of Turbo's or a Supercharger. No money in the budget now though.

i have been guessing 450 also but she sure isnt getting the top end i expected. the internals are still cast which is the biggest reason that i want to upgrade the short block. if i had a forged lower end i would just throw some better heads on and call it a day. i drove a boat with a 502 efi with a vortec supercharger a few weekends ago and that thing just hauled. i was thinking if i can hit 650hp without boost i would be doing similar to that boat. my thing is, the boat with a 89 gen 5 330hp would run 5000rpm with the 23 pitch 3 blade and now i have at least a 100hp more with the same prop and i am still stuck at 5000 rpm so maybe instead of a new short block i should be trying to figure out what i need to do to get over 5000. i have thought about trying a set of mag heads and see what happens? i guess in my mind i really should have a forged lower end and if i am gonna do that why not stroke it for almost the same price and throw the mag heads on.... and since i have a good motor that i am gonna use nothing more the the block for the next one why not find another block and leave it assembled as a back up? i can still pull the cam and all of that, if i toast the new motor i can have it out and swap everything out by the next weekend and back on the water. i keep finding gen 4 blocks for cheap but i really want to stick to the gen 6 since everything i have is set up for it and i honestly believe they seal up better not to mention i if i use the 731 cam again i need a roller block.

Throw all that crap you got in the dumpster and buy a brand new Hp 502 long block from Summit Racing!!You will never have to worry that some guy who rebuilt your motor did it right. It will cost you less money in the end.....



Jim

The part #is NAL12496963 and it comes with a limited warranty
502 Horses at 5200 rpm and 567ft.-lbs of torque
9.6:1 compression

I started with 330's (2 bolt mains) and 049 heads. Got the forged stroker kits (with H-beam rods and KB 9.3 forged pistons) then decided I HAD to put 4 bolts on it (add $500/ea). Went isky roller cam/retro lifters. heavy duty push rods, scorpion roller rockers, inconel exhaust valves 1.88 and larger intakes too. had the heads reworked (i.e. started throwing good money after bad) RPM intakes, and add a list of low value items that nearly broke the bank, new guide plates and rocker bolts, ARP Stud kit and head bolts, new valve covers because the rockers didn't fit, new timing chain cover, x-over, and last but not least new carbs because the 750's were no longer cuttin the mustard. Dyno'd 540hp at 5400 (torque monsters though)

Did everything but the machine work myself. Total without carbs, exhaust and other misc bs came to ~$5K/ea. I think I saved a few bucks doing it myself... but I also feel I left a few pony's on the table. I also could have saved if I started with a plan/budget and stuck with it.

Perfect example of what I was talking about ------------in last post !



Jim

um, i put my motor together my self...... and i trust my work!