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View Full Version : Re-Power a 1972 HM302/VP270 Ski Sporter 16



72Sweet16
02-16-2012, 08:05 PM
Hello All ... I've been reading here on the forum for a while, but this is my first post (and forgive me for it getting pretty long).

I am the second owner of a 1972 16, which I acquired during the summer of 1973 - needless to say I've had many, many, many years of enjoyment and memories with this fabulous little boat. It has spent its entire life exclusively in fresh water in the lakes and rivers of north Alabama and Georgia and has never presented any major issues.

However, now is the time when I skip the long sob story about the "friend" who returned it to me one fall and failed to winterize it. That pretty well brings us to the present - frozen/cracked block. I wish I could say I have tons of money and could just "drop in a new crate motor" . . . reality is I will have to either find a core and re-build or try and source a re-man.

A must also admit that I am no mechanic and am not qualified to do the work personally; my only wrenching experience is on Harleys. Most of my buddies that will be volunteering on the project are HD or automotive guys - no marine expertise among us. Any help/suggestions you guys can throw my way will be greatly appreciated - I certainly want to try and avoid as many "gotcha's" as I can.

So ... what would you guys do in my situation?

Thanks in advance . . .

Gary S
02-18-2012, 09:56 AM
Since no one has answered I'll give you my thoughts. I would source another block and go from there.Trouble with that is the extra work and the "I might as well do this too" syndrome. Maybe the easist way for you to go as far as getting you back on the water at a known cost would be to buy a long block and add your HM marine parts.Where ever you go to get one make sure they understand it's for marine use,they use different clearances and have brass core plugs.I spend most my time on the Correct Craft fan site but stop in here to see whats happening with those who have Holman Moody engines.My HM started out as a 289 and like yours must have had a problem since now it has a 302 block. Some of the members have used engines from here http://www.rapidomarine.com/ and seem to have been happy but some miss communication problems arose when they needed reverse rotation engines.

zelatore
02-18-2012, 02:11 PM
I wouldn't discount doing the work yourself. You may not be up for rebuilding the motor yourself, but if you and your friends are semi-handy with a wrench I'd say you can handle a simple swap. There's plenty of help from this forum to get you past any questions you might have.

To keep things simple a new long block would be the easiest thing. As was mentioned, a 302 would be easier to find, just make sure it's set up as a marine engine. You can re-use all the accessories on your existing motor, though you'll likely want to replace the manifolds/riser as they are service items.

Take a lot of pictures and take your time, and you can do it! the hardest part will be physically getting the motor in/out of the boat. The 16 is a tight fit, and most guys don't have a way to lift an engine that high. Some do it with a regular cherry picker like they'd use on a car, but it can be tough getting over the side of the boat. At least with the small block you don't have too much weight to deal with. I've done it, and you'll find taking the wheel off the trailer helps a lot. Some guys use a come-along to a reinforced rafter in their garage - that might work but make sure you've got the strength and not just a 2x10 alone. Or you can do what I did and pick up a cheapo Harbor Freight overhead gantry, though I doubt you'd want to go that route unless you think you'll have more uses for it as they take up a ton of room.

72Sweet16
02-18-2012, 02:23 PM
>>
Since no one has answered I'll give you my thoughts. I would source another block and go from there.Trouble with that is the extra work and the "I might as well do this too" syndrome. Maybe the easist way for you to go as far as getting you back on the water at a known cost would be to buy a long block and add your HM marine parts.Where ever you go to get one make sure they understand it's for marine use,they use different clearances and have brass core plugs.I spend most my time on the Correct Craft fan site but stop in here to see whats happening with those who have Holman Moody engines.My HM started out as a 289 and like yours must have had a problem since now it has a 302 block. Some of the members have used engines from here http://www.rapidomarine.com/ and seem to have been happy but some miss communication problems arose when they needed reverse rotation engines.
<<

Thanks much for your thoughts and input . .... you've described my dilemma perfectly ! I seem to be in the mode of "while I have it out of there" I should go ahead and ???????
My temptations are a new style roller 302 block and a stroker kit. But, that'd mean new flywheel, tuning issues and all the other fitment problems I don't know about.

I found Rapido recommended on several other sites, too . . . . as of this wk he didn't have any old style short blocks, but only add'l $150 for long; $1,680 lift-gated to my shop. The simplicity of that scenario is very tempting. And, as you say - a known fixed cost.

Thanks again,
Clark

f_inscreenname
02-18-2012, 03:18 PM
Take pictures is the #1 thing so you know what goes where when time to put it back together.

72Sweet16
02-19-2012, 12:30 PM
Hey Guys . . . I've tried to reply using the "reply with quote" link, but so far none have actually posted to the forum So, now I'm trying the "reply to thread" link . . . here's hoping this shows up!!

Gary S -
you've described my dilemma perfectly; I'm infected with the "while I have it out of there disease" ! My temptation would be a good old style 302 block and a stroker kit. But that would possibly involve new cam, flywheel, tuning problems and heaven only knows what other problems I'm too ignorant to even think about. I have seen Rapido suggested on other forums/sites, too - as of this wk he didn't have any old-style short blocks, only longs. But, even at that - $1,680 lift-gated to my shop is a very tempting solution from both a fixed cost and simplicity perspective.

Zelatore -
Between myself and volunteers, we're willing to tackle the removal/re-install ... if I just do a short/long block basic "back to stock" replacement. It's my temptation for more that starts me to question the work required and the time line. As of now, we do have the engine out of the boat with intake, heads, exhaust and externals removed. Hey, I can take things apart as good as anybody - it's the putting them back together that's always the problem ! <g>

F-inscreenname -
As both you and Zelatore have said: excellent suggestion.

So, THANX !! to all you guys; for now consensus seems to be just replace what I had . . . . all I gotta' do is fight off the thoughts of a moderately built Scat 347 stroker . . . .

joseph m. hahnl
02-19-2012, 01:25 PM
I would add, Go the little extra for a hydraulic roller cam. If you go with a higher grade rotating assembly ,there is always room for bolt on horsepower:wink:.

72Sweet16
02-19-2012, 02:14 PM
Joseph M. -
Yep - that's the kind of thinking I'm accustomed to as well. But, it also starts the domino effect that always bites me in the wallet , too! Like, a nice roller block with a little more cam. . . then new aluminum intake . . .. just a little headwork . . . slightly bigger carb . . .. If only I could identify all the components, price them and the machine work; then I could be more willing to commit. It's that open-ended thing I gotta watch out for.

THANX !!
Clark

joseph m. hahnl
02-19-2012, 06:01 PM
Joseph M. -
Yep - that's the kind of thinking I'm accustomed to as well. But, it also starts the domino effect that always bites me in the wallet , too! Like, a nice roller block with a little more cam. . . then new aluminum intake . . .. just a little headwork . . . slightly bigger carb . . .. If only I could identify all the components, price them and the machine work; then I could be more willing to commit. It's that open-ended thing I gotta watch out for.




You can up grade any thing on top at any time. The internals are a one shot deal.It's like a nest egg you build the block for the future. Flat Tappets are obsolete If there is one, and only one mod you ever do it should be a roller camshaft:yes:

72Sweet16
02-19-2012, 06:40 PM
Ahhh . .. . that makes a lot of sense - and is exactly the kind of advice I was hoping to get from you guys on this forum. Problem is, here's where my automotive ignorance kicks in: if I go roller block, am I not required to replace flywheel -or, can one get an "old-style" roller block? My understanding is old style use 28oz and new, roller style use 50oz . .. . if this isn't true and I can use my old flywheel (which I presume is 28), that'd be a really big plus . . .

joseph m. hahnl
02-19-2012, 09:18 PM
They sell retro fit roller cams for the older flat tappet blocks



http://www.edelbrock.com/automotive_new/misc/tech_center/install/9000/97384.pdf

72Sweet16
02-20-2012, 07:31 AM
Joseph -

Even more good info . . . install sheet says shorter than stock pushrods required; further either adjustables or adjustable rocker arms, with the rocker arms being preferred. I'm familiar with adj. pushrods of course, but not rockers; are these considered "exotic-overkill" or are they pretty common? Stock ratio OK?


THANX again !! and pls keep those helpful hints coming,

Clark

BTW, do you have a good reference source for marine cam specs? . . . any way to get the specs on the original one?

mattyboy
02-21-2012, 09:40 AM
I have just done this on my boat, in hind sight I should have just canned the 302 and gotten a small block chevy setup and mated it to the volvo. In the end it would have been more economical. Things you'll need to keep and eye on: the ford setup hasn't really changed over the years but there are little things that will drive you nutz the HM water pumps are hard to come by now and depending on what HM front motor mount you have the fuel pump and water pump replacements could be an issue. I had the existing long block rebuilt and tweaked a little go lighty with the cams as ford hi-po exhaust systems are not readily avail. and are big $$$ for custom.

Gary S
02-21-2012, 11:51 PM
It's my understanding that a 347 is not a good marine motor something to do with the rod ratio and high constant rpm? the 331 is supposed to be a better choice. You HM parts also would fit a 351 which I think can be stroked to a 427. I have no stern drive experence but that might be your next problem if you were to up grade the motor. At least you have some options,Im stuck with a flat tappet cam because I need a reverse rotation one. Here's a pic of my HM,I just added 25 hp by putting on HM valve covers ;)

70170

72Sweet16
02-22-2012, 08:40 AM
mattyboy -
Glad to hear you made it thru the process with yours . . . I'm expecting a few "gotcha's" before I finish, and that's why I've posted here - your suggestion about converting to the Chevy has been echoed by others in various places/forums. I just don't know that I have the expertise/patience/courage to undertake that right now. At the moment, I, too, am leaning towards a re-build. I've sourced an "old-style" block that (if it passes magnaflux) is going to become my new motor. I'm still struggling over going back with my internals and a little "freshening" vs moderate enhancements, i.e. stroker kit. Hopefully my water and fuel pumps can be convinced/coerced into bolting onto the replacement block. As for the cam, that's one of my biggest decisions yet to be made. I have no idea what the specs are on the original, nor have I found a good reference to aid in selecting a new one if I choose to go a little more aggressive and/or roller (for either stock or stroker).

Gary S -
Stroker concerns - I'm betting the comments about the marine implementation of a 347 have to do with piston speed specs. Since I don't foresee endless hours at red-line, but more in the common 2,500 to 4k range, I'll just have to do the math - very good point, though; and one I need to consider. But I do have another motor with much longer stroke, i.e. 4.375, that has seen many, many hours in the 3.5 to 4.5k range - it's been fairing well now for going on 10 yrs. (but it does have all forged internals)
(BTW, did you see Joseph m.'s post above about Edelbrock's roller tappets for a flat tappet block?)

As for the 351, I have certainly considered that, too. There are just lots of things I don't know: would the extra 1 to 2" deck height actually fit under my deck lid? . . . or what problems the wider exhaust would present in mating up to the transom?? . . . .or who knows what else? Oh NO!!! - here we go again - if a 351 will fit, then how much for the 393 or 408 stroker kits ??????

Anyone gone that route? And, as you say, at what point can the 270 say that's enough !! <g> (not that I ever expect to get there - hmmmm, maybe with that 408 and a set of those 25hp HM Decals ? :hyper:)

THANX !! again guys . .. and pls keep it coming.

mattyboy
02-22-2012, 08:48 AM
the 270 will be the least of your problems it will handle anything a NA small block can throw at it

do you have a serial number off the HM motor I might be able to track down the cam specs, that should be a 235 hp motor if nothing has been touched. you also need to think exhausts on a ford ,that is always the biggest hurdle. you'll need to keep that in mind during your build no sense in building something that can't breathe or even worse something that chokes on water when you bolt up the risers.


Gary BTW I have some reverse rotation parts I think I have a starter new I'll let it go cheap let me know

72Sweet16
02-22-2012, 09:06 AM
Hmmmm . . . . . I thought I had that stuffed away in my computer somewhere, but can't find it at the moment. But, I think you're spot on about the 235; seems I found that somewhere a few months back. I know the HM plate specified 9.5:1 and, other than a new coil and carb re-build, it's still as it was on day one. It did come w/351 heads and 450 Holley. As far as the exhaust, I truthfully don't see my going beyond the 347. You think the original exhaust would be OK there?

And, since I don't have the budget right now for anything but NA - that's good news about the 270.
I'll see if I can't get that engine # . . .. really appreciate any help on cam choice!

THANX !!
Clark

ps to Gary S - forgot to mention in my last post; great pic of your HM . . . . and I love those valve covers !! :hyper:

mattyboy
02-22-2012, 01:36 PM
I am assuming you still have the HM/glenwood logs I never had an issue with them on a 310 hp 351 but it has been said that they can be tough on the two back cyls. you probably want to look for barr alum center risers 4 inch would be best but you're on that slippery slope now .........................

72Sweet16
02-22-2012, 07:34 PM
I do still have the originals - and am hoping to re-use (after some serious clean up). I plan to stay w/mild to moderate, so the 310 shouldn't be an issue; especially if I stay with just the 302.
Ah yes . . .. . the slope; temptations, temptations :hyper:

THANX !!

Gary S
02-22-2012, 08:04 PM
You could always call Holman Moody and ask Lee about the cam.He is the son of one of the original founders and was the one involved on the marine side.I have called before and he actually answers himself. http://www.holmanmoody.com/contact.html

Matty,thanks for the offer, right now I'm pretty well set but you know how that goes.

JimG
02-23-2012, 06:53 AM
Last time I called about my cam grind, the original cam guy was still there. He spouted out the specs, as I scrambled to write them down. Mine is a 351, but I'll try to find them anyway.

I use the original logs. Actually they are a hybrid of Edelbrock manifolds and HM risers. I've never had a problem at all. Good performance and light weight. I like them so much I just bought a second set, (all HM) that I'm having powdercoated...

mattyboy
02-23-2012, 07:58 AM
as it was explained to me a guideline or rule of thumb you'll need to address a stock exhaust once the hp and cubes meet. Mario and magicbill here are the ones i would talk to they have built warmed up fords. I have the specs for the 351 around here some where going thru all the stuff i have on my build I have 302 and 289 info here somewhere. on a side note i did find my registration which i was looking for.

72Sweet16
02-23-2012, 08:49 AM
Good Morning Guys . . . tx for all the info.

Gary S-
I have called and talked w/them before - very gracious and helpful; but didn't think to ask about cam specs at the time. I still can't find my notes w/all the numbers and my buddy's shop is on the other side of Atl from me, so may still be a few days before I can get them again . . .

JimG -
Glad to get the nod on the original logs . . . hope mine clean up OK.

mattyboy -
After getting some preliminary nbrs from machine shop, looks like the stroker is out . .... so 302 it is. Having said that, with my plans of a mild/moderate, it really doesn't sound like the stock exhaust/logs will pose a problem. I just don't want to push this one to the point of 1 to 1; boat engines are just way to hard to pull compared to Harleys !

As for the cam specs/selection, I'm gaining confidence w/the machine shop . . . turns out the guy that owns/runs used to be with Reed Cams; he has some really serious CAD/CNC equip. Merely pulls the old one and runs a full profile on it. He can then bench the heads and suggest cam profile based on flow nbrs, desired compression, etc., etc. . . . will even custom grind on site if needed (oops - slippery slope again :yes:). Also has lots of marine build experience .. .

You guys have been really helpful with all this . . . . looks like most of my big fears/concerns have been addressed and now my wallet can start making decisions. I'm hoping to pick up my "new" engine candidate today and then get it and the old one to the shop by the first of the week. Once the block is assessed, it'll be time for the fun to begin.

THANX !! again to all.

BTW, anyone know the approx. empty weight of the entire boat? hull, engine, outdrive and all?

mattyboy
02-23-2012, 09:04 AM
That's what I did after hemming and hawing I Just let the shop do the voodoo what they do.Mine is just a little short of the original 289 hi-po number of 270 hp.

yes the stock logs will be fine not sure where the exhaust outlets on yours are , on my 16 with the 351w they were higher than the early boats with 260-289 interceptors which were lower near the water line. My point just make sure you have flappers of some kind. rebuild it and enjoy for another 40 years :)

JimG
02-23-2012, 11:06 AM
I think around 2200lbs...

72Sweet16
02-24-2012, 07:07 AM
mattyboy -
Yep - sounds pretty much like my plan: since my hopes of the stroker 347 are gone, then Just Let'em do ! . . . as for my exhaust outlets, I'm pretty sure they're the "high" ones; the hose connectors between the snails and the outlets are pretty much level. And they do have the original "flappers." As for another 40 years, the Donzi may make it but I'll be lucky to see 20 . . . .

JimG -
"I think around 2200lbs..."
good info sir! The weight question has already been raised wile discussing cam profiles.

Meanwhile, back at the ranch . . . . . got a chance to inspect my new motor candidate yesterday. Bad news is, it's cracked worse than mine. So, back to the drawing board searching for a buildable block. Anybody got an old 302 laying around ?? or, was it ever determined a 351 would fit?? :smile: If you guys happen to know where one is in the Atlanta metro area, lemme' know .. ..

THANX !!

mattyboy
02-24-2012, 09:48 AM
the 351 is taller and the exhaust exits will be higher not sure if there is enough length between riser and the transom fitting to make up the difference in height with some kind adapter. might need glass work on the transom. also not sure the front motor mount is the same for the 351 and then you wind up right at the top of that slippery slope again

here is a shot of the 351 exhaust exits on a 16 you can judge by how high they are in relation to the volvo transom housing

mattyboy
02-24-2012, 09:56 AM
If you look on my 16 the 351 exits well above the side point of the transom plate if you look at the 289/302 brochure boat the exits are right at the side points of the transom plate you can also judge by the boot stripe which can been seen just under the water in the brochure pic and the water line coming up right to the middle of the transom plate with the exhaust just above that. If you look at my pic you can see the water line stain/ discoloration on the transom housing and my exhaust well above that.

Gary S
02-25-2012, 09:21 AM
ps to Gary S - forgot to mention in my last post; great pic of your HM . . . . and I love those valve covers !! http://www.donzi.net/forums/images/smilies/hyper.gif That picture has the original ones on it,here are the new HM ones
70227

jl1962
02-25-2012, 10:44 AM
I never really focused on the thru hull height. The brochure boat is certainly lower than Matty's old 351 boat, but my '67 289 boat also has the higher placement - not surprising since my build (#420)probably overlapped w/ Mattys (#410).

70228

mattyboy
02-26-2012, 08:59 AM
just a little more info for anyone interested.

Jay, mine were about where yours are when it left the factory but when holman moody marine in long beach ca. re-rigged the boat and removed the 289 and aq200 in 1969 and installed the 351w and aq250 they moved the exhausts . the increased deck height over the 289/302 also means the tips are farther apart too. I don't think that 72's 16 has them but then there are the real early interceptor boats where the tips are low and wide.


as seen here on this 16 hull number 136

72Sweet16
02-26-2012, 09:56 AM
Good morning all ... I've been away from the pc coupla' days, so sorry for delayed post.

I really appreciate all the good info about exhaust location for the different yrs/configurations; unfortunately I'm about 200 miles from the boat at the moment and can't check it nor do I have any pics - so can't really compare mine to any of those examples you guys have put up .... But all the different possibilities seem to point back in the same direction - stay with the 302 - transom/glass work, fabricated exhausts, etc., etc. just aren't in the budget for now (plus, I'd prolly go back to the stroker plan if funds were available). :yes:

BTW - you guys are killing me w/all these pics of your gorgeous **Complete and Running** boats !! And the freshly built motor w/great looking covers and exhaust !!

I'll be back in Atl by mid-week . . .. then maybe I can get some exhaust measurements and pics. I really gotta' make a decision and start block searching...

THANX !! again

ps - here's a scanned copy of a really old photo of mine: white on white w/white interior. mattyboy, looks to be like the last one you up-loaded, albeit a couple hundred hulls later

72Sweet16
02-26-2012, 10:15 AM
OK guys . ... I realize I'm prolly dreaming here, but what all would I have to do to adapt this one ?? Even if I had to re-cam and convert back to carb, seems like a helluva' buy @ $1,500. ..

As quoted in the ad:
Mustang 5.0, factory roller short block, ported and O-Ringed E7 heads with heavy springs (setup for nitrous or boost), GT-40 Tubular intake ported and gasket matched, 70mm BBK throttle body and EGR plate, C&L 76mm Mass Air Flow Sensor with power pipe, 24lb injectors, 1.7 Ford/Crane roller rockers, Cloyes True Roller 9 keyway timing set, race harmonic balancer, Canton Drag Race oil pan, underdrive pulleys, A9 computer, complete harness, BBK headers, Ford Distributor with MSD wires, new water pump, starter. All new Felpro gaskets throughout. Does Not come with flywheel. Just about everything you need for V8 conversion except transmission. May have more included parts to list, just cant remember all of it. There are a ton of expensive parts on this motor.

Sold the car that it was going in. Complete and ready to drop in whatever you want. Perfect for your 4 cyl Mustang V8 conversion, 240z V8 conversion, Miata V8 conversion, Ratrod, etc.