468 vs 454 vs 502
 

I am considering a 468 motor from totalamp

But I am not familiar with that particular cubic inch.

I have a 454 and know a bit about a 502.

Why would one be better than the other?

or is it not so cut and dry -- assume good parts on all three motors why would one be better than the other?

do cube's always win out?

I don't see much info here on the 468

any help is appreciated!

thanks!

Mark

Mark,

All three--- 454, 468 and a 502 normally have the same 4" stroke. All a 468 is, is a 454 that has been bored out .060" over. A 502 is basically a 454 only with a larger (4.470" I think) cylinder bore size which really starts unshrouding the valves and thus starts making some decent horsepower. The 502 requires a different block that has thicker cylinder walls to accomodate the larger bore size required to make it a 502" engine. They are usually refered to as a siamesed cylinder wall block. A standard 454 block cannot be bored out to the cylinder bore size of a 502, but it can be bored out safely to a 468" engine. Again, each of these engines 454, 468 and 502 all use the same 4" stroke crankshaft and the same rods. The only difference between the 3 are the piston bore sizes. If your wallet can swing it, buy the 502. Hope I have expained it well enough for you.

And remember, there is reliability in cubic inches. Best wishes :)

Mark/KAAMA

thanks -- that does help


after i thought about it a while -- i figured the 468 was a bored out 454.

its a good deal on the motor

this is part of the spec i have received

what else should i be asking?


468c.i. engines. Just built 5 hrs. Forged SRP pistons, steel crank and rods. oversize Gil Offshore oil pans,Merlin heads, Dart aluminum intake and Holley Marine carb.

making 525hp

mpejsa/Mark,

Also, if you have the engine torn down to have it rebuilt you may consider having the cylinders "bore notched". This will give you about 25-30 additional torque and HP. It's cheap reliable power.

Mark, Well, not knowing who assembled it or how it was assembled or how it actually runs, by what you're saying it sure sounds as if there's A LOT of sweet parts in there. If it's in the price range you're looking for it may be a good buy. Have you seen/heard this engine run?

Also, what kind of exhaust system do you plan to run?

I have not seen the engine yet -- it is by totalmp -- in louisana

I currently have stock "log" exhaust and am looking to upgrade that also.

It is a good price on the motor - and he'll buy my 330 off of me.

I am mechanically inclined -- but do not know the ins and outs of what parts are good with what.

I guess what I am also saying is I am trying to find out how totalmp (aka stephen at total marine performance) is known -- as far as engine building goes.

Mark, I haven't heard anything bad about Total MP. What you might want to do is go into the "General Discussion" area and let post it on there that you're considering buying a used engine from Total MP and ask if anyone has delt with Total MP good or bad, and see what kind of responses you get. I know a few guys have delt with them and it been good, but I don't know of their engine building practices or how they deal with people when it comes to used parts.

Mark/KAAMA

thanks mark -- i'll do that

its hard to word it in a way as to not offend Total MP -- but i want to do my due diligence also.

Mark, you are a consumer and that is one of the BIG things of what this forum is about and yes, wording it in a way as to try and not offend would be a wise thing because I think you know that things can get out of hand on here real easy.

KAAMA, you are right on the 4.470 bore of a 502. A 509 is 4.500, or 0.30 oversized 502 (to get REALLY technical it is 4.466" and .034 over). By the way, can you explain bore notched to me. I am pretty sure I know what you are refering too, but I might be wrong. I'm trying to visualize it (how scaryis that!!??!!) Thanks.

mpjesa, do you know what kind of tq numbers the motor makes??

Yep; I need to learn about "bore notching" too!! Who really knows, and where is some good reliable printed info. Or maybe a website or whatever!!?! Where can I get to basics on this ?? --- Jer

Call "JimV" he does this for several of his customers and has dyno'd a 454 with a bore notched block and with all components remaining the same he said he saw a 30hp/tq gain! You can call him. 616-735-0800

Also, Tinkerboater has done this for a lot of local offshore boaters. It's not a difficult procedure---you just have to do it correctly. I think JimV has some pictures on his homepage---I think.

Thanks KAAMA; I'll head that way. --- Jer

Find JimV's name within this forum and click on "Profile" when his page pops up then click on his "hompage" address that he has listed. This will obviously take you to his homepage and then click on the word "tech tips" and a picture will pop up showing a bore notch job with some explaination underneath the picture. You have to know what you're looking for to see the bore notch job in the picture---it's right where the deck of the block and the cylinder bore meets. Regarding the flow of the intake valve, it's usually more crittical on the intake side of the bore but it can also be done on the exhaust side of the bore as well.

JimV just made a post in the "I want a little more power from my 572" thread here in the Technical Q & A section. Go find it and it and click on his PROFILE and it will take you where you need to go.

Going there KAAMA. Thanks again!! --- Jer

mpejsa,
Take your time and do the research there are a lot of options for you to consider.
One may be to price out a general motors crate motor 502.
The motor does come with steel crank, roller lifters and cam, one piece rear main seal, one piece oil pan gasket, and delivers around 450 Hp out of the box.
Post what you dicide to do.
Good Luck
Brian

Thanks Kaama, I'll check it out in a few minutes.....

This engine is not used. We are currently taking it down to inspect all components. Upon inspection, it will be reassembled w/ all new rings, bearings, etc. We are a reputable shop and are willing to work with anyone to build the engine that best fits their needs. Our main focus is reliable HP. We will be more than happy to provide references to those interested.

You are the consumer, feel free to ask anything you want, we won't be offended.

Thanks,

Steve

Compression?
 

What is the compression ratio?