Engine guide-gctid344961

[Guest]

I'm looking for a good marine engine rebuild guide... I have a pretty good idea on what I want, just want to do it the right way for me...

I have googled some and there is way too much info that contradicts itself.

Thanks

Mike

[2850Bounty]

Mike............. Can you be more specific?

moconnor wrote:
................ there is way too much info that contradicts itself......

.... such as?????

[yachtman]

Dennis Moore marine performance book but if you can find it its going to cost you $200+.

[Guest]

I'm pretty sure I want go vortec....long skirts.....roller....right at the 300hp number...I just want to make sure of what I can and cannot use from the pre-vortec setup.....I have some numbers ...but I enjoy doing some of the leg work myself..

And I agree. $200 for a book is a little high....

Mike

[2850Bounty]

moconnor wrote:
I'm pretty sure I want go vortec....long skirts.....roller....right at the 300hp number...I just want to make sure of what I can and cannot use from the pre-vortec setup.....I have some numbers ...but I enjoy doing some of the leg work myself..

And I agree. $200 for a book is a little high....

Mike, Dennis Moore's book is very informative, but is out of print and that's why it is so expensive to buy these days. I won't even loan mine out.

However, your local library can bring it in for you!

It may take a week or so, but they should be able get their hands on a copy.

There are several, so you'll want make sure it's the [COLOR]"#0000FF" wrote:
Small Block Chevy Marine Performance[/COLOR] book.

As for pre-Vortec.... you're talking 1995 SBC, correct?

That block should be set up for the roller cam..... i.e., the fwd thrust area (roller followers allow the camshaft to float...unlike flat tappet followers), cam follower anti-rotation keepers, and the hold down tray.

The Votec Cylinder Heads are basically a bolt-on item.... Vortec intake is now 8 bolt.... no exhaust cross-over.

One trick, IMO, is using the correct pistons and head gasket underneath the Vortec head as to take the best possible advantage of this unique wedge area.

Dennis will go into detail on this.

The rest of the build can be rather standard.

Yes... no long rods and no short skirts would be best.... which is a whole story by itself for another day!

[Guest]

Duuh....why didn't I think of library...I'll give them a call thanks.....I bought the boat at an estate auction last spring and got no past history...knew the heads were cracked so I installed those new...correct year...and boat ran fine for the season but I'd bet I'm not pulling 150 hp . After living with the 2855, we like it so it's worth fixing right. I have discovered over the summer, the engine was not original so again, I don't know for sure what I have...

Research will answer my questions...

Thanks again

Mike

[2850Bounty]

moconnor wrote:
Duuh....why didn't I think of library...I'll give them a call thanks.....

............. and boat ran fine for the season but I'd bet I'm not pulling 150 hp.

I have discovered over the summer, the engine was not original so again, I don't know for sure what I have...

Research will answer my questions...

Mike ....., yes, reserching what you have would tell you quite a bit..... and especially if this engine had been replaced by ???? and with ????.

Pull a valve cover and take down the cylinder head casting number.

The engine block casting number will be AFT and port side just ahead of the flywheel cover engine flange.

The displacement number (in liters) will be right there also (5.0 or 5.7)

Or use Merc's serial number tag.

Do you remember what the piston decks looked like???

Did they have a dished shape to them..... or another shape... or perhaps flat?

Here's an example of what may have happened since you changed cylinder heads on an alleged unknown block (not confirmed.... but just say'n).

Let's say that the block was fitted with GM full dished pistons.

The full dished pistons require the small cylinder head chambers (typically the 64cc's) in order to maintain the correct C/R.

Let's say that the new heads were 76cc chambers.

You will have now lowered the C/R substantially.

That's just an example.... I doubt this is the case.

If it is a 1995, it may be a roller cam engine, in which case I highly doubt that you have a camshaft issue.... the roller cams and followers seem to outlast the engines.

If you remember the piston shape, I think that your casting numbers will give you some answers.

Edit:

Mike, I'm still interested in hearing about the information you're seeing that contradicts itself. Perhaps we can shed some light on it for you.

.

[yachtman]

Vortec heads are a good choice but you need to know their limits.

As long as you use the proper pistons they work well. They can support 400+ horse power. Not that you build it for that.

The first problem with vortec heads is the cam profile has to be some what mild but that is fine as long as you aren't interested in using a cam shaft with more than say .420. Much more than that you will have to make modifications to the valve spring seats and upgrade the springs.

In the last few years gm made a .500 valve lift version so when you get your heads make sure you know what you have.

If you are wanting more valve lift than a vortec head offer it might be worth taking a look at the edelbrock 6089 aluminum rpm heads as long as you have closed cooling that would be a good choice for several reasons. Weight savings being and better detonation control are some of them

To use vortec heads you will need a vortec intake manifold and the valve covers are center bolt style. All else is the same.

[Guest]

I have an 89 Bayliner 2655. I'm selecting a motor for repower and am considering this from Michigan Motorz: http://www.michiganmotorz.com/vortec...rent-p-68.html.

Besides an electric fuel pump and a new manifold, will I need anything else? Do I need to swap the flywheel?

Will the pick up of 40-50hp be worth the extra effort/cost over this: http://www.michiganmotorz.com/marine...795-p-167.html.

Thanks,

Greg Hodges