Whats a Holman moody 302? |
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h20loo
Senior Member Joined: August-30-2008 Location: Canada Status: Offline Points: 225 |
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Posted: September-13-2008 at 9:23pm |
Its a rainy day and I've spent most of it on here searching for info on HM302. What I'm looking for is what makes it different to a regular 302. My block and heads have 302 cast on them but I haven't seen much else. Anybody have specs on these motors, valve size,piston type etc. or can point me to a site that does?
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70 Mustang project
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Tim D
Grand Poobah Joined: August-23-2004 Location: United States Status: Offline Points: 2641 |
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It has different exhaust manifolds, no circ pump and I guess more hp and maybe better assembly.
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Tim D
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h20loo
Senior Member Joined: August-30-2008 Location: Canada Status: Offline Points: 225 |
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Thanks Tim- what year and boat is yours in and are those clear or braided waterlines going to the manifolds?
I took mine out for a run before I started disassembly and with the performance it has and the reverence thats paid to Holman moody on this site I just expected to find dual points, aluminum intake and some bigger valves etc.I know- its only 25hp difference and only turns 5000 rpm. There's signs of balancing but I don't know if its factory as the pistons are 30 over. Other than a resto on a 65 2+2 with a 289hipo I have never touched a ford so this is all new to me. I'm going to clean everything up, check the tolerances,put in a new rear main seal and play with the heads abit. Is there any gasket sets that are recommended for ford marine engines. Thinking about a 327 stroker- any thoughts? I have to go back and read Joes thread again. |
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70 Mustang project
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8122pbrainard
Grand Poobah Joined: September-14-2006 Location: Three Lakes Wi. Status: Offline Points: 41045 |
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Doug,
I feel the people who can give you the answers to your questions on the internals are off at the reunion. Wait a couple of days and I'm sure they'll tell you. The only thing I know is the H/M gains were due to the rather free flowing exhaust manifolds. You mention a 25 HP difference in HP. From what? In 70, the other engine offered would have been the 225 HP (318) Chrysler. |
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boat dr
Grand Poobah Joined: June-27-2004 Location: United States Status: Offline Points: 4245 |
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Doug, built a 331 for my '64.Spent a lot of time on research and a considerable amount on the build too.
The biggest hurdle for you to overcome will be the rear oil seal. I chose to go with the newer one piece rear main block.That seal is very difficult to come by. If you choose to bore and stroke your block,it has a two piece rear main,you will have to knurl your new stroker crank.This can be done , but cannot give you the name of a shop that can do this mod to the new crank. Pete can verify the added increase in HP gained by this Stroker method.......Boat dr I will be glad to add what i can to your info folder........... |
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h20loo
Senior Member Joined: August-30-2008 Location: Canada Status: Offline Points: 225 |
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Pete "You mention a 25 HP difference in HP. From what? In 70, the other engine offered would have been the 225 HP (318) Chrysler.""
I was thinking about the 210hp 302.But you made me smile because a stroked 360 would be up my alley and I have a 6pak(not beer) sitting here that would be awesome to use. Owell- back to the ford. Dr-everything I say here is from what I have read and not what I have done and therefore it may or may not be worth a $hit. Yes the 331 is the best pkge to drop in a 302 but The reason I was thinking 327 is I think (but don't know this for sure) that I could build up MY crank and regrind the journals for the added stroke. I knew there was a problem with the reverse rotation fords when it came to the seal and I thought the327 would get me around that.That and I do like the numbers matching block. Abuddy thats a "go fast guy" sez I should just go with GT40 heads and see if there is a better aluminum intake for the power band I'm running. Then if I still need more I could stroke it. "That seal is very difficult to come by" Do you mean the 1pce reverse rotation seal? "built a 331 for my '64" I know this may be a trade secretand ifso, just don't answer but which heads and cam did you go with, what prop supported the new power? My boat was touching 49mph off the trailer without any tuning or hull prep. My weigh with a full tank of fuel and trailer is 2136. I haven't been able to run just the trailer across the scale but I dont think I have excess water in the hull. When you add 30 gallons at 180 lbs? If my numbers are correct then the boat is around 1600lbs?!! Anyways-50 mph is enough for this hull so all I really want to work on is the hole shot. Thanks for your replys Doug |
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70 Mustang project
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Gary S
Grand Poobah Joined: November-30-2006 Location: Illinois Status: Offline Points: 14096 |
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From what I understand from Reid other than the items used to convert to marine there are no other differences,just a production Ford engine.Mine originally only had a 2 bbl carb.What I ended up doing with my crank was to have the knurling removed,then a speedy sleeve installed by a machine shop
http://www.alliedbearings.com/mfg_prod/seals/cr_speedi/index.html I used the the original type of rope seal,no leaks in 18+ years, but now very hard to find. |
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boat dr
Grand Poobah Joined: June-27-2004 Location: United States Status: Offline Points: 4245 |
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Doug the one piece RR rear seal is hard to find, there is no difference on the two piece, the knurling keeps the oil away from the seal.
As far as mods to my 331, it too was done for punch and not for top speed.Cam Research did the bump stick,GT-40 heads, Edelbrock Performer intake and a 600 cfm Holley. Mallory Uni-Lite dizzy w/ matching HO coil. The crank driven raw water pump , removing the circ. pump along with the polished Hi-Yek SS headers were done as much for weight saving as the performance and HP gains. All in all I am very satisfied with the power and speed that this little motor produces. For skiing and pulling I run a 12x14 cupped .025 for tooling around I run a 12x15 w/ a mild cup and still spin it 5200 rpm's.. Still looking for that 60 mark, the roller rockers and a little hull work will do the trick ......Boat dr |
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Tim D
Grand Poobah Joined: August-23-2004 Location: United States Status: Offline Points: 2641 |
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When I put roller rockers in mine, I noticed the most difference in the mid range power.
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Tim D
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MaddMarxx
Platinum Member Joined: June-29-2006 Location: United States Status: Offline Points: 1741 |
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Holman-Moody shop 1968
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h20loo
Senior Member Joined: August-30-2008 Location: Canada Status: Offline Points: 225 |
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Maddmarxx- I remember those Torinos 'cause they were never to far behind the Chargers!!! LOL
BTW- I sent an email to you(it was returned) a while ago asking if you had any pictures of your boat you could send me. We really like the whole boat but especially the color. Thats one nice looking ride! Doug |
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70 Mustang project
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h20loo
Senior Member Joined: August-30-2008 Location: Canada Status: Offline Points: 225 |
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[QUOTE=Tim D] When I put roller rockers in mine, I noticed the most difference in the mid range power.
[IMG] Tim- what ratio,cam and heads and what did you notice? What I'm looking for is the balls to pull a couple barefooters out of the deep and still run close up to 50mph. |
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70 Mustang project
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Tim D
Grand Poobah Joined: August-23-2004 Location: United States Status: Offline Points: 2641 |
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I don't remember the ratio of the rockers, the cam is a Clevite, a little hotter than stock and it changed the firing order to that of a 351.
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Tim D
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reidp
Platinum Member Joined: December-06-2003 Location: Mooresville, NC Status: Offline Points: 1804 |
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Doug, while HM indeed built thousands of hard core race engines for cars and boats, the long blocks on the engines used by companies such as Correct Craft, Donzi, etc, were typically identical to those marinized by other companies. In the very earliest days however, mainly about '64-71, HM used the "premium fuel", i.e., higher compression versions of those long blocks provided by Ford, which resulted in slightly more HP than the other marinizations. Most common examples of this were the early 225HP 289 and 235HP engines which were approx 10:1 and 10.5:1 compression engines as noted on the engine I.D. tags. The competitors 4-barrel 289 and 302 engines at that time were 210-220 HP, and typically used 8.5-9:1 CR's. HM's 2-barrel version used in a good number of CC's was rated at 210HP and had 9.5:1 comp, again, the same as the automotive counterpart of that day. Also, the first HM 4-barrel 351's which debuted in '69 and ran thru about '72 were 290HP, 10.7:1 CR engines which mirrored the auto version. But no standard alum intakes, or other performance adders on the stock assembly line engines being warranteed in factory boats. They did however, sell a variety of high perf engines and parts directly over the counter for any customer that wanted them. As far as HM's marinization package goes/went, they had a few items which distinguished them from many of the rest of the time; aluminum freer-flowing exhs, chrome valve covers, rear engine mounts attached to an alum bell-housing instead of the trans, making it much easier to pull a trans, many with double belted pulleys (unlike one above), etc.. The HM engine wasn't even the most expensive option as evidenced by a price sheet somewhere on this Site. Both the Chrysler and OMC I believe were more expensive. The engine manual(s) for these HM engines are mostly available thru Marineengines.com or some site like that.
As for your goals to yank a couple footers with a good holeshot, you indeed have several options: You can go the stroker route as Billy mentioned above, or build the 302 you have now. Our 302 herehttp://www.correctcraftfan.com/diaries/details.asp?ID=184&sort=&pagenum=1&yrstart=1969&yrend=1969 will certainly do everything you want, but if you're planning to pull multiple footers often, then there's no substitute for cubic inches and Billy's 331 definitely has more pull/holeshot than this 302, although the 302 might have as much (or more) horsepower. And if you add the HP for the holeshot, you will automatically get the added bonus of 50+ mph speeds, with no need for any special props other than those noted by Billy or myself. |
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h20loo
Senior Member Joined: August-30-2008 Location: Canada Status: Offline Points: 225 |
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Thanks Reid and Doc- lots to think thru in those few paragraphs!!!
I better go make some $$ and then thinkings easier!!! |
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70 Mustang project
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h20loo
Senior Member Joined: August-30-2008 Location: Canada Status: Offline Points: 225 |
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Gary S provided this info on the build tag on my motor:D9HM-3708 2 RWT
Doug,not to step on Reids's toes,he is after all the HM guru, I have the info right here. The 9 is for the year of the engine which is 69, that fits since your boat was built in early 70. The 2 is for right hand rotation. D is the size 302.3708 is the serial #,RW is raw water cooled and T is a 12 degree drive |
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70 Mustang project
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