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boatnut
01-11-2011, 02:55 PM
My son and I have been discussing doing some renovation work on a Donzi we have had in the family for 40 years. It is a '69 18 with H&M Ford/Volvo power. I would brag (without facts) that this boat has to be in the top 5% of all unrestored Donzis of its era. It is almost like a new boat with orig gelcoat and all original power (except for a couple of head changes over the years). We started thinking about upgrading the power as the boat still runs around 50 mph but the lower end of the engine has not been touched since new 42 years ago. And then, from a lot of research on this forum a few years ago we decided that we had to remove the deck and change the tank, even though we have no evidence of tank leakage -- the safety issue is there. We now have to stop thinking and start doing. As many of you know, prior to starting such a task there are many basic decisions that have to be made:
1) how original do we want to keep the boat
2) power and drive, chevy vs ford, merc vs volvo
3) speed performance
etc. etc.
We have decided to keep the boat as original as we can. Even down to reusing as much of the H&M labled parts as we can. That means we will go with Ford pwr and a Volvo drive (probably the 250 that is now on the boat).
I have been doing some new searches on the site to review lots of the past articles esp the ones on deck removal. Scary stuff but the info on this forum will be priceless --- so I will have to donate some more to assist with the costs of this valuable resource. We will not measure up to the level of excellence some (like George Carter) of you provide but we want to do the job as well as we can.
My first questions this year (don't know how long this will take) involve the engine. Our current thinking is to use a new crate engine (not even sure what the term "crate" exactly means in this context). We want an engine with heads that we can buy rather than rebuilding our engine. New would be best but I guess rebuilt is possible. Horsepower is still open, the current engine is the H&M 302 235hp pkg. I believe H&M just purchased a Ford truck block and marined it. The exhaust and intake manifolds have H&M logos on them and we want reuse them. (I realize the exh manifolds are not the best but we want to try to duplicate the boat when it was new as much as possible.) I also want to reuse the water pump, and thermo housing, plumbing from H&M as much as possible. So now the questions:
1)If I want to bolt all of these old parts on the new engine, what choices of engines do I have -- will all 302's for example accomodate these parts or do I need a certain vintage/year model engine?
2) And likewise, will later model heads for the 302 accomodate the H&M intake manifold from this 1969 engine?
3) Do the 351W engines have exactly the same bolt patterns for these parts as the 302 engines do? Is there any reason we couldn't use a 351W and still use all the H&M components? (Other than our quest for originality might favor the 302) Will the 351 fit under the hatch OK, engine height the same?
4) Any suggestions on specific engines, year models, and sources?
Again, while we would like to step up from the 235 hp and find a solution that provided 300+ hp with reliability--- keeping the H&M flavor is most important.
Thanks in advance for your comments and guidance. I have added a couple of pictures. Ed

jl1962
01-11-2011, 03:01 PM
Great looking 18.
Where in CT are you?

boatnut
01-11-2011, 03:04 PM
thanks, the northern California part of CT :) .

jl1962
01-11-2011, 03:33 PM
Oops!

Oh yeah, CF. I'm awake.

Still a very nice boat!

Good luck w/ the tank. Lots of good threads here.

mrfixxall
01-11-2011, 03:46 PM
nice ride!.. if the boat has not seen salt water like mine has not, i wouldn't even worry about the fuel tank, your in Cali and i have seen the way metal turns after 20 years,,it just dont rust..if it ain't leaking then dont fix it,i have the oe tank in mine,when i did my resto i pulled the metal tank and their was no rust what so ever inside or out..i had them seal it up and reused it..mostly the salt water boats had rotted fuel tanks..

Engine,it would be cheaper to rebuild what you have, flat top pistons,zero deck the block, with the newer cam grinds and mild head work you can get a easy 320 hp out of that engine..

Tony
01-11-2011, 05:04 PM
World Products, so says Jack Roush:

http://www.worldcastings.com/products/cylinder-heads/small-block-ford-heads/

gcarter
01-11-2011, 07:14 PM
Ed, take a look at what Ford has to offer;

http://www.fordracingparts.com/crateengine/main.asp

And I wouldn't miss an opportunity to change the tank.
You absolutely can't tell the condition of the bottom of it.

Also I'd take this opportunity to completely replace the wiring.
A lot of the old hardware isn't safe anymore, particularly circuit breakers, etc.

It's a worthy project.
Good luck w/it.

zelatore
01-11-2011, 09:45 PM
Since you're a fellow NorCal guy, and none of the more knowledgeable types here actually answered this part:

No, a 351 won't accept the intake from a 302. The 351 block has a higher deck height and is therefor slightly wider. Although the heads can be shared and therefor the exhaust, the intakes are unique.

Later 302s however should be no problem.

302s in general gain the most from heads, however if you're sticking with the stock intake and exhaust I don't think there's a lot of reason to go crazy with aftermarket aluminum heads. You'd loose weight, which would be good, but a good set of earlier iron heads might flow well enough in your application. As I recall (and it's been years so I may be wrong) '69 Windsor heads were among the best stocker for a budget 302 build.

You could also do a stroker 302 - I believe you can get about 331 out of them though I haven't done it myself. Going that route you can find more power and still have a totally stock look.

Where are you in NorCal? We're building quite a local contingent here!

BUIZILLA
01-11-2011, 09:58 PM
You could also do a stroker 302 - I believe you can get about 331 out of them though I haven't done it myself. Going that route you can find more power and still have a totally stock look.
347 is eazy...

maddad
01-11-2011, 11:07 PM
If you're going to make real power and use those log style exhaust manifolds you must spring for severe duty/Inconel valves. The valves in the back take a beating with them.

boatnut
01-12-2011, 02:43 PM
Thanks to all, very helpful.
Mr Fixxal, I hear you about the tank, it has been the one point that has stalled us for so long as removing the deck is a big step from a mechanical update. However, I have experienced crevice corrosion before. It only requires moisture (with or without salt) without sufficient oxygen to badly pit metal including stainless or aluminum. The potential is there even though we have no indications so we will replace the tank and we may very well pull a good tank --- the forum will find out soon after we do.
On your engine point, I would reconsider rebuilding our engine if I knew of someone locally I could trust to do the job properly. It remains an option however it seems buying another engine has less risk.
George, I had visited Ford Racing's website before. I think I will try to call them and discuss what I am after to see what they have that is completely compatible with the '69 302 we have. They might also know if Ford has more conventional (without exotic heads etc.) crate engines available. The tank and wiring is part of our plan. As is a thorough inspection of the shift/throttle/steering etc. Once you make the step to remove the deck all must be considered which is your point I believe. I wish I had your energy and glass skills, we have a good boat guy locally that does all aspects of glass work and he will work with us to resolve any hull issues we find.
Don, thanks for the 351 and other eng info, very helpful. I will focus on the 302 blocks. I have property on Clear Lake, about two hours from your area. My son who shares this project with me, is a firefighter in Sacramento and lives in Newcastle.
Don/MadDad, the exhaust manifolds remain an open item. I would like to keep them because they are H&M, look good, and are light. But they are not the most efficient and are very old. I built up some pitted areas maybe 20 years ago by heliarcing. I also had problems over the years with rear valves as you mentioned. They will have to be carefully inspected. There aren't many options avail in marine exh manifolds for Fords (unlike SBC's) that I have found. Any suggestions?
Thanks again to all for your time and talent, Ed

gcarter
01-12-2011, 02:51 PM
Ed, if Ford is like GM, these engines are sold through dealers and the dealers do negotiate. While looking at GM engines on the internet, for instance, I found differences of up to $5K on BBC's.

boatnut
01-13-2011, 01:03 PM
As I try to figure out what 302 to get (or build), the exh manifold issue is again front and center. I mentioned in the begining of the thread that we will just keep the H&M log manifolds in the interest of originality (and neat looks). But after searching old threads in the forum on ford exh manifolds (including some of my own posts way back then) I am reeling from info overload. However, it is clear that in addition to some reduced performance these H&M log manifolds could have caused some of the problems I have had over the years with valve/head issues in the rear of the engine. I esp focused on some posts from the Griz (sure miss his input) that indicates these manifolds should be dumped. Then what to get?? Not many good choices as I don't want to add a lot of weight either. Of interest is the HiTek Aussie manifolds. Some have used them based on old posts. Jeff V, Moody Blu, not sure if you guys follow any of the boring stuff like this thread but I think you have these manifolds and was wondering if you could confirm that they would fit within the hatch constraints on my '69 18 with a 302. Or any other users with experience, I would welcome your comments. Such info might be in the research I just tried to do but as I said, info overload. I was also wondering if the Hi Teks would require different thru transom hole locations -- I can do that but need to know before we do the glass work on the hull. Thanks for the help. Ed

joseph m. hahnl
01-13-2011, 05:56 PM
Funny: You live in the performance capitol of the world and you can't find a motor guy.:rofl:. It is easier to rebuild a motor than it is to take the deck off.:yes:. All you Really need to do is have the block professionally trued and sized. Cylinders bored and honed, Line bored, and decked. assemble it yourself with a forged steel crank and pre fitted forged pistons. The short block will be bullet proof.Then you don't need to worry about accessories bolts lining up,and you can bolt on all the performance mods you'll ever need. Ohh:eek: Then you can brag it has the original motor:pimp:. I didn't say it was the stock original motor:wink:

Any way that's my opinion on it:shocking:, What ever you choose, I'm sure will be the right decision for your own wants and needs :boggled:

boatnut
01-13-2011, 08:26 PM
Funny: You live in the performance capitol of the world and you can't find a motor guy.:rofl:. It is easier to rebuild a motor than it is to take the deck off.:yes:. All you Really need to do is have the block professionally trued and sized. Cylinders bored and honed, Line bored, and decked. assemble it yourself with a forged steel crank and pre fitted forged pistons. The short block will be bullet proof.Then you don't need to worry about accessories bolts lining up,and you can bolt on all the performance mods you'll ever need. Ohh:eek: Then you can brag it has the original motor:pimp:. I didn't say it was the stock original motor:wink:
Any way that's my opinion on it:shocking:, What ever you choose, I'm sure will be the right decision for your own wants and needs :boggled:
Well Joseph, thks for the vote of confidence. I actually live in the grape squeezing capital --- but I agree with a few hours of driving I could find a good CA engine shop. I actually have built many engines when I was a kid and was forced labor in my Dad's shop. I just have been doing other things for 50 years and don't have the current knowledge to get the kind of results I want. I also have a block that has been in a boat for 42 years including some salt use (although I always rinsed it well). By the time I find a good guy to do all the magnafluxing, cleaning, boring, building, parts buying etc. I just thought a good crate motor might be a better bang for the buck. However I understand what you are saying and that clearly is the backup plan-- it is cast iron that has been aged for 42 years so it is stable at least :wink:. thks, Ed