Need help with 888 mercruiser repower

[oldgmfart]

I posted a similar question over at the restoration section being as I'm going all thru the boat, but maybe this part is better asked here.

I'm needing help and ideas on repowering a mercruiser 888 in a 1974 25' Bayliner Saratoga.


Reason being is the motor will be coming out shortly for replacement, figure now's the time to add some updates and a little more power. I'm curious to know how much more power a stock 888 sterndrive will handle? (not neccesarily more rpm), if any?


Do any of you think it would be smart stay close to the original engine/outdrive configuration as I can to save $$, and adding a few horses the o.e. engine?....or just going w/ a newer motor and drive combo? Hoping to use as much of the stock ford 302 periphials as I can... i.e, raw water exh., distributor, alt, starter etc. I imagine someone, somewhere has done something similar in the past.

Sure appreciate any ideas on this. I plan on posting alot of pics of this swap and restore as soon as I'm underway with a good game plan.


Appreciate all input.

Thanks,
Ted

 

[frank246]

Re: Need help with 888 mercruiser repower

The 888 outdrive will deal some 300 hp if it is still in a good condition.
You can re-place a dual plane intake manifold and a 600 cfm Marine carb to your replacement 302 engine so it becomes a 220 (hp) combo instead of the 888 188hp and still be able to reuse all the other hardware. Be aware of the pre `80 crank balancer weight diff.
Good luck

 

[oldgmfart]

Re: Need help with 888 mercruiser repower

This is good news. I'll plan on keeping the current drive in place and change it later when a proper gear change requirement needs figured out. Since it sounds safe to go with this drive and a peppy 302 build, how's about I find me a good mid-90's Explorer 5.0 litre and rebuild for marine application??

Good heads up on the crank balance issue frank!

If I go with a later model 302 as stated above, would there be some posts on here or some links you know of on finding the proper balancer/flywheel/coupler parts I would need to pull off such a swap? I have researched a bit already but haven't gotten to the sources for the right part numbers yet.

Regards

 

[coastalcruiser]

Re: Need help with 888 mercruiser repower

I'm needing help and ideas on repowering a mercruiser 888 in a 1974 25' Bayliner Saratoga.

here is a link to my repower thread I sold the 888 and got something newer
managed to find a used motor drive wiring and guages
sold my old 888 really happy with how it worked out and it fit right in the old cutout

http://forums.iboats.com/showthread.php?t=295182

here is the results post. the old bayliner has hit 45 mph and the fuel economy is much better

http://forums.iboats.com/showthread.php?t=303897

 

[oldgmfart]

Re: Need help with 888 mercruiser repower

Man, that is one nice "refit" you've done Coastal C... See, this is why I love coming here. Not only do I get encouragement and ideas by seeing similar projects accomplished , but people like you also give alot of inspiration and great ideas that otherwise wouldn't have been considered.

Beautiful work there Sir!

I see your up in Nanaimo! I'm darn near your neighbor down here in Seattle.

 

[haulnazz15]

Re: Need help with 888 mercruiser repower

Was the 888 less than a 1.5:1 drive? I suppose it could have been a 1.8:1 ratio or so, but you may just be able to reprop it as opposed to swapping outdrive gears.

 

[oldgmfart]

Re: Need help with 888 mercruiser repower

Actually it is the 1.5:1 drive Haulinazz. I think I'll take you up on that one and just test first then reprop accordingly for best performance and proper rpm @ wot.


He,heh..."best performance" on a 25' foot Bayliner he says...lol.

Anybody have suggestions for what year/type of 302 I should build for this?
I read somewhere on here and over at a few other forums that the later model Ford Exploder engines are a good platform to start from....any truth to that?

 

[buzzlol]

Re: Need help with 888 mercruiser repower

.. I'd rebuild the '188HP' 2 bbl 302W of the '888' with a $270 rebuild kit and marine 4 bbl carb. (rebuilt $260 at Summit Racing or used one) and '225HP' 4 bbl cam or slightly bigger cam... like a Summit K1103...

http://www.northernautoparts.com/ProductModelDetail.cfm?ProductModelId=2239

.. For more power $600/pair World Products Windsor Jr. iron heads with 60cc chambers and 2.02"/1.60" valves... some explorers also came with improved heads...

.. For even more power add a 347" stroker kit... about $700... from enginekits.com

.. Higher flowing top center outlet marine exhaust manfolds setup from a newer 302W or 351W... more expensive is Stainless Steel marine headers...

 

[haulnazz15]

Re: Need help with 888 mercruiser repower

Just rebuild your 302 if it is in good shape, there's no difference in the later model 302's except for the heads (GT40P) and a one-piece oil seal. The GT40P heads (64cc) have a different spark plug angle than all of the other 302/351W heads, so you might want to check to make sure they'll fit with the exhaust manifolds. All in all, as long as you have pre-1977 heads, they can be machined to fit 1.96/1.6 I/E valves and will flow good enough for a marine application.

I wouldn't bother with aftermarket aluminum heads just because they will run you more than 1K for new ones that won't give you much, if any, more power in the range from 1000-4600rpms.

Here's list of what I'm doing on my 351 (btw a 351 is a cheap upgrade from a 302 if you want close to 300HP)

1) Machined block and heads to accept .030 Keith Black hypereutic pistons. All machining/decking to bring compression somewhere between 9.1-9.5:1 compression.
2) Comp Cams 254-grind cam kit (includes valve springs, keepers, guides, cam , timing gears/chain, etc)
3) Edelbrock Performer 4bbl Intake and 600cfm (p/n-1409) carb

Those are the basics of my build and should get me in the upper 280's-290's on HP, and maybe 350ft-lbs of torque on a 1975 351W. I am actually replacing every single part on the engine aside from the external accessories, so don't accept my few items as the only cost. It will run me $2500-3000 by the time it's done doing most of the work myself.

Hope this gives you a bit of direction.