Want more sound(Holman Moody 302)
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Category: General Correct Craft Discussion
Forum Name: General Discussion
Forum Discription: Anything Correct Craft
URL: http://www.CorrectCraftFan.com/forum/forum_posts.asp?TID=12080
Printed Date: April-29-2024 at 1:17am
Topic: Want more sound(Holman Moody 302)
Posted By: HM302
Subject: Want more sound(Holman Moody 302)
Date Posted: September-30-2008 at 8:15pm
| I have a 73 model boat with a Holman Moody 302 and I want it to be a little louder than it already is. I am wondering if I can get louder manifolds or if I could actually modify the manifolds I have now to where they would be louder. |
Replies:
Posted By: jbear
Date Posted: October-01-2008 at 12:03am
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I can't answer your questions Ryan...but welcome....you are my kinda guy.
john ------------- "Loud pipes save lives" AdamT sez "I'm Canadian and a beaver lover myself"... |
Posted By: critter
Date Posted: October-01-2008 at 12:19am
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I take it that there are no mufflers ??
I have no mufflers on my 80 and it seems loud to me. ------------- 1980 Ski Nautique 1966 Barracuda |
Posted By: boat dr
Date Posted: October-01-2008 at 12:47am
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HM302 add a set of GT-40 heads and a set of Hi-Tek Stainles Steel Exhaust manifolds.These two mods will possibly get you a citation from the Water Cops.
The heads will raise your compression ratio the manifolds will increase flow.Your little 302 will pick up a few HP and loose some weight to boot. Both are a win win in a boat..........Boat dr ------------- boat dr /diaries/details.asp?ID=4631 - 1949 Dart /diaries/details.asp?ID=1533 - 1964 American Skier |
Posted By: jbear
Date Posted: October-01-2008 at 12:50am
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You lnow there are no mufflers on my '80 Roger and I admit it is very loud. Just the way I like it.
john ------------- "Loud pipes save lives" AdamT sez "I'm Canadian and a beaver lover myself"... |
Posted By: critter
Date Posted: October-01-2008 at 2:28am
John, I think that you and I are right on with the 80s. No mufflers needed. Keeps the mosquitoes away. 
I asked Reid to take my boat out at GL to help me with a vibration. His 1st comment was that there were no mufflers.. then he nailed the vibration to the Prop. So I guess the noise did not distract him.  ------------- 1980 Ski Nautique 1966 Barracuda |
Posted By: jbear
Date Posted: October-01-2008 at 2:38am
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What prop you running? I have an Acme 540...love it. Also have an OJ 13x13 Legend...this is good too. In fact..MM likes to borrow it from me.
Love them loud 80's don't we? Reid is a pretty handy guy to know. john ------------- "Loud pipes save lives" AdamT sez "I'm Canadian and a beaver lover myself"... |
Posted By: reidp
Date Posted: October-01-2008 at 10:44am
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HM302/Ryan; You're the first guy I've ever heard say that his 302 HM wasn't loud enough, as they typically seem to be the loudest. Now while I hardly EVER disagree with the BoatDr, I'm not sure of two things: I'm big on the GT-40 heads, but your vintage 302 came with 351 small chamber heads which result in about the same comp ratio as the regular GT-40's. Boatdr is thinking about the more commom later model 302/351 heads which had small valves and large (low compression)chambers. As for the manifolds, JoeinNY and a few others feel that the aluminum HM's might be louder than the stainless Hi-Teks. So unless someone had installed mufflers in your boat over the years, there's little you can do to make it louder without internal mods to raise your compression and changing a cam, but that's quite a bit of work. I can certainly testify that my HM302 is now VERY loud, so since you're not too far from me we should plan to meet up sometime and you can hear it run and see if that's what you're really after. Give me a call sometime if you like. 704-451-5080. ------------- ReidP /diaries/details.asp?ID=231&yrstart=1971&yrend=1975 - 1973 Mustang |
Posted By: Riley
Date Posted: October-01-2008 at 11:23am
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Reid, I'd say your boat won the award for loudest boat at Lake George. Even louder that Tim B's SN. I didn't think JoeNY's with the High Techs seemed as loud as Tim's. Maybe something to do with Tim's SS pipes? But, your boat was louder than both. It also seemed to vary more from quiet to very loud. Almost like a cut out. ------------- |
Posted By: 8122pbrainard
Date Posted: October-01-2008 at 11:45am
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Ryan,
At 21 you shouldn't be needing hearing aids yet so hopefully that's not it. I agree with Reid on this one. I too have never heard of anyone wanting to increase the H/M's sound level. I can here one start up from the other side of the lake and know it's a H/M from the distinctive bark they make. The only louder boats are V drives or I/O's with rear mounted engines and short through the transom exhausts. (H/M rear engines especially!!) Have you had this boat for awhile or just get it? Does it have the original H/M manifolds or has someone put on generic cast irons? Like Reid mentioned, maybe a PO put mufflers on it! Get a flashlight and look up the exhaust pipes for signs of mufflers. ------------- /diaries/details.asp?ID=1622" rel="nofollow - 54 Atom /diaries/details.asp?ID=2179" rel="nofollow - 77 Tique 64 X55 Dunphy Keep it original, Pete < |
Posted By: JoeinNY
Date Posted: October-01-2008 at 12:01pm
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I almost suspect shananigans here, either non original manifolds in play or something odd in between the exhaust and outlet. Either way I have never seen a holman moody I/o setup and would love to see some pictures.
I tend to agree with Reid that heads and hitek manifolds on the HM/302 are probably not going to all that pronounced a difference at least not for the price. HM's have relatively good equipment to begin with, the heads are decent and the exhaust relatively lightweight and normally very loud even stock. I have not played with the HM manifolds much but I know that some fairly heavy porting helped my aluminum commander style manifolds. I agree with Riley my boat with the Hitek's is not all that loud compared to Reids with HM manifolds, and my 83 with a 408 higher compression bigger cam no mufflers, steel pipe, etc is nowhere near as loud as my 67 with a fairly stout 302 and 3 inch aluminum manifolds not even close... ------------- http://www.correctcraftfan.com/diaries/details.asp?ID=1477 - 1983 Ski Nautique 2001 1967 Mustang 302 "Decoy" http://www.youtube.com/watch?v=cO5MkcBXBBs - Holeshot Video |
Posted By: TRBenj
Date Posted: October-01-2008 at 1:22pm
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I agree with Joe and Reid. The '73 with the H-M manifolds is the loudest CC Ive ever heard. Definitely louder than my '90, which I think is comparable to the stock H-M Mustangs Ive heard.
We shouldnt forget that Ryan doesnt have a CC, though- so the exhaust set up is a bit of a question mark. Like Joe said, whether or not the boat still has the original manifolds is still a question mark. Who knows if there are any mufflers. I also cannot tell if the exhaust outlets are 3" like CC would have used... If not, then enlarging those would probably be the easiest way to gain sound.  ------------- |
Posted By: Brktracer
Date Posted: October-01-2008 at 1:57pm
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1. Exhaust
2. Cam 3. Compression My '76 is fairly loud. It has 9:1 compression (for 87 octane) and 224@.050 cam. I don't like the OSCO (aftermarket PCM) manifolds as It's my opinion they're too restrictive! But...I'm too cheap to buy some HiTeks. I keep checking ebay for some better manifolds but can't find any! No doubt compression and cam will make it louder. My race car will make your ears ring! 14.5:1 w/ 273@.050! I wear ear plugs! ------------- http://www.correctcraftfan.com/diaries/details.asp?ID=3180 - 1976 Nautique |
Posted By: 8122pbrainard
Date Posted: October-01-2008 at 2:26pm
Interesting!! I didn't connect the Dixie boat with H/M302 ether. I'd like to see some pictures too. Joe, the only H/M I/O's I've ever seen are in the Donzi's. Who on site has extra "powered by H/M" decals?? ------------- /diaries/details.asp?ID=1622" rel="nofollow - 54 Atom /diaries/details.asp?ID=2179" rel="nofollow - 77 Tique 64 X55 Dunphy Keep it original, Pete < |
JoeinNY wrote:Posted By: reidp
Date Posted: October-01-2008 at 3:55pm
OK, I'm lost or did I miss a post? How did Tim know that Ryan's wasn't a CC and is that Ryan's Dixie. The Dixie boats were built close by Charlotte and actually quite a few came with HM's back in the day. As for the decal Pete, if you hadn't seen it already, you can get one here: http://cgi.ebay.com/ebaymotors/1960s-Holman-Moody-Patch-Decal-Lot-of-3pcs_W0QQcmdZViewItemQQ_trkparmsZ72Q3a1205Q7c39Q3a1Q7c66Q3a2Q7c65Q3a12Q7c240Q3a1318QQ_trksidZp3286Q2ec0Q2em14QQhashZitem130259044762QQitemZ130259044762 - http://cgi.ebay.com/ebaymotors/1960s-Holman-Moody-Patch-Decal-Lot-of-3pcs_W0QQcmdZViewItemQQ_trkparmsZ72Q3a1205Q7c39Q3a1Q7c66Q3a2Q7c65Q3a12Q7c240Q3a1318QQ_trksidZp3286Q2ec0Q2em14QQhashZitem130259044762QQitemZ130259044762 or here: http://www.holmanmoody.com/parts1.html - http://www.holmanmoody.com/parts1.html EDIT: Duh!! Nevermind, as I just found the post about the Dixie in the other posting. ------------- ReidP /diaries/details.asp?ID=231&yrstart=1971&yrend=1975 - 1973 Mustang |
Posted By: HM302
Date Posted: October-01-2008 at 5:18pm
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Well sorry for the slow response but here are some more pictures.
Ive had the boat and been running it the past two summers over here on W. Kerr Scott. Next year I really want to go up to Lake Norman as much as I can. She sounds real good and is loud but I guess I am just looking for a little more, haha. Thanks for all the good info and responses so far fellas... oh and as for those stickers I just went to the holman moody website and then called them and ordered them 
|
Posted By: HM302
Date Posted: October-01-2008 at 5:23pm
| Oh yea and sorry I didnt specify that it wasnt a Correct Craft. I just never can find any good info or anybody to talk to about Dixie boats and I thought this website seemed really cool, I figured I could atleast have some people to talk to about my motor. |
Posted By: 8122pbrainard
Date Posted: October-01-2008 at 5:37pm
Ryan, Well, now I may have spoke too soon regarding the hearing aids!! Thanks for the pictures. A rear H/M with above the waterline through the transom exhaust - you can't get much louder! How about over the top straight pipes??? ------------- /diaries/details.asp?ID=1622" rel="nofollow - 54 Atom /diaries/details.asp?ID=2179" rel="nofollow - 77 Tique 64 X55 Dunphy Keep it original, Pete < |
Posted By: critter
Date Posted: October-01-2008 at 5:37pm
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You are always welcome here
This is a friendly place. ------------- 1980 Ski Nautique 1966 Barracuda |
Posted By: HM302
Date Posted: October-01-2008 at 5:42pm
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Haha maybe I do need hearin aids, everything I drive is straight piped, I love lots of sound
thanks critter |
Posted By: JoeinNY
Date Posted: October-01-2008 at 6:16pm
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Whats the diameter on them there thruhulls, I almost want to say they are not 3 inches... ------------- http://www.correctcraftfan.com/diaries/details.asp?ID=1477 - 1983 Ski Nautique 2001 1967 Mustang 302 "Decoy" http://www.youtube.com/watch?v=cO5MkcBXBBs - Holeshot Video |
Posted By: reidp
Date Posted: October-01-2008 at 7:14pm
Good eye Joe!! A 3" or 3-1/2" O.D. on those thru hulls would certainly make it talk out loud. Ryan, you'd need a spacer of some sort around the end of the manifold (thin strip of 3" hose), but then you could go with the 3-1/2" thru-hulls for extra noise. I bought a set of these (3") and they are NICE!! http://www.buckalgonquin.com/pages/ProductPages/exhaust/tran_exh_stra_page.html - http://www.buckalgonquin.com/pages/ProductPages/exhaust/tran_exh_stra_page.html I know converting a Correct Craft from the smaller 2-1/2" thru-hulls found on many pre-70's boats to a 3" system definitely adds to the sound. FYI, most CC's with small block Interceptors, Grays, and pre '67-'68 Chryslers (poly 318's) used the smaller exhaust pipes. The HM's and later small block Chryslers all had 3" exh manifolds which dictated the hose and thru-hull size and that became the norm. Most big blocks were 3" I believe. Oh, and Ryan, I love those valve covers. But you've got to clean them up! ------------- ReidP /diaries/details.asp?ID=231&yrstart=1971&yrend=1975 - 1973 Mustang |
Posted By: TRBenj
Date Posted: October-01-2008 at 8:56pm
Geez guys, didnt I already say that?
Just busting your balls- Im positive that particular tidbit originally came from a conversation I had with Mr. P. Id be curious to hear how that Dixie runs out... and definitely clean up those valve covers! ------------- |
Posted By: HM302
Date Posted: October-01-2008 at 10:43pm
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Yall know your stuff, I just measured my exhaust outlets and they are only 2 3/8". Those thru-hulls are nice reid. I think I want me some 3.5" ones. What would I need spacer wise like you were talking about? I kinda would like to get new rubber hoses on both ends that are more smoother instead of the ones with ridges.
Yea I plan on cleaning them up and doing some other odds and ends to her over the winter, I guess I have been to caught up with having so much fun driving her around on the lake all the time. |
Posted By: Gary S
Date Posted: October-01-2008 at 11:13pm
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Ryan I don't think you could make that sharp bend with smooth hose maybe someone will have an idea- ------------- http://www.correctcraftfan.com/diaries/details.asp?ID=1711&sort=&pagenum=1&yrstart=1966&yrend=1970" rel="nofollow - 69 Mustang HM SS 95 Nautique Super Sport |
Posted By: reidp
Date Posted: October-01-2008 at 11:13pm
|
Crusader engines from the very early 70's like TRBenj (Tim's)with log manifolds used a 2-1/2" outlet on the exh's but used a short "sleeve?" of 2-1/2" hose around the exh outlet and then put the 3" full-length hose over that. That was the simple spacer type deal I was refering to above. It would be best to see if you can't find some pre-bent rubber hoses in the 3-1/2" dia as the exh hose will be hard to bend that tight. You may have to find some tight radias pipe in stainless, fiberglass or some other material and just use some very short pieces of rubber hose to make the connections, as you don't appear to have much horizontal distance to work with.
Tim, sorry we missed your initial revelation. ------------- ReidP /diaries/details.asp?ID=231&yrstart=1971&yrend=1975 - 1973 Mustang |
Posted By: reidp
Date Posted: October-01-2008 at 11:29pm
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Wow. Looking back at the pict showing the flex hose in the radias, it might be better to at least look at welding a SS radius to the inside of the thru-hull. It'd have to be such that the radius would fit thru the transom hole of course. You could end up with a slick mini-version of Tim's SS exh. Look that up if you haven't seen it already Ryan. ------------- ReidP /diaries/details.asp?ID=231&yrstart=1971&yrend=1975 - 1973 Mustang |
Posted By: HM302
Date Posted: October-01-2008 at 11:30pm
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If I use some 3.5" pre bent house then I can probably use smaller pieces of hose to put around my manifold and then just put my 3.5" piece over those and then tighten her down? I think thats what you were saying right
Do you remember how much those thru hulls were?..polished stainless |
Posted By: HM302
Date Posted: October-01-2008 at 11:32pm
| How would I find that setup you just mentioned? |
Posted By: reidp
Date Posted: October-01-2008 at 11:35pm
|
In terms of the smaller pieces, that's exactly what I was talking about.
As for Tim's set-up I should have been more specific as he has a plethora of CC's here. http://correctcraftfan.com/forum/forum_posts.asp?TID=6888 - http://correctcraftfan.com/forum/forum_posts.asp?TID=6888 ------------- ReidP /diaries/details.asp?ID=231&yrstart=1971&yrend=1975 - 1973 Mustang |
Posted By: Gary S
Date Posted: October-01-2008 at 11:36pm
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Reid, look at the 1st and 2nd pic's.I don't know if it's an optical illusion, but it dosen't look like the thru hulls are straight back from the manifolds either,complicating matters more ------------- http://www.correctcraftfan.com/diaries/details.asp?ID=1711&sort=&pagenum=1&yrstart=1966&yrend=1970" rel="nofollow - 69 Mustang HM SS 95 Nautique Super Sport |
Posted By: reidp
Date Posted: October-01-2008 at 11:46pm
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Yep, Gary. Looks like he's gonna needs Tim's fabricator too.
Ryan, I can't remember the exact cost of the thru-hulls, but I believe mine were in the $50-60 range each, and the 3-1/2's could be a little more. But don't settle of cheap imitations as these will look sculpted just like your originals. ------------- ReidP /diaries/details.asp?ID=231&yrstart=1971&yrend=1975 - 1973 Mustang |
Posted By: critter
Date Posted: October-01-2008 at 11:59pm
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Ryan,
Cheapest I can find those thru-hulls is $81.20. http://www.jmsonline.net/TRANSOM-EXHAUST-SS-W-3-HOSE.htm?zoom_highlight=exhaust - 3" Thru Hulls That is the 3in because the 3 1/2in are only listed in Bronze. Not sure bronze would look good. ------------- 1980 Ski Nautique 1966 Barracuda |
Posted By: HM302
Date Posted: October-02-2008 at 12:07am
| Wow, thats some nice exhaust tim has there. Yea I was just curious as to price but I definately want some 3.5" polished, I sent them a email to get some info on the 3.5" ones. What is the diameter of the ends of my exhaust manifolds? |
Posted By: reidp
Date Posted: October-02-2008 at 12:10am
|
Roger, the bronze ones I've seen are typically chrome plated, so that look great as well, but then you'd have a bigger issue welding if need be. ------------- ReidP /diaries/details.asp?ID=231&yrstart=1971&yrend=1975 - 1973 Mustang |
Posted By: critter
Date Posted: October-02-2008 at 12:15am
Reid, I looked at that site you provided and noticed that the 3 1/2 were listed with a Part number of "n/a" for the SS. It did not provide a part number for chromed Bronze. ------------- 1980 Ski Nautique 1966 Barracuda |
Posted By: HM302
Date Posted: October-02-2008 at 12:19am
| I see that what you are talking about Roger. I didnt notice the n/a before |
Posted By: reidp
Date Posted: October-02-2008 at 12:25am
|
The HM exh dia is 3" O.D. for the main portion of the outlet, with a small lip around the end the goes to like 3.2" but does go around a 3" pipe.
EDIT: And I guess I wasn't paying attetion to what you saw Roger as it does say "cast bronze" and not chrome. Well Ryan, you may have to go to 4", and I'll hear you up on Hwy 421. ------------- ReidP /diaries/details.asp?ID=231&yrstart=1971&yrend=1975 - 1973 Mustang |
Posted By: critter
Date Posted: October-02-2008 at 12:30am
|
Keep making that thru hull bigger and before long you will be able to use chainsaw to cut it..
EDIT: I have got a couple 5lb coffee cans in the kitchen that I can let go cheap. A chainsaw and a little 5200 and you will be set. ------------- 1980 Ski Nautique 1966 Barracuda |
Posted By: quinner
Date Posted: October-02-2008 at 12:41am
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That's got to be one of the badest Tri-Hulls I have ever seen. What is that 302 rated at for HP, 210? That boat must really move, what do you guy's think the top end would be?
Also, would a rigid Exhaust connection be OK in that setup? Cool Boat Ryan! ------------- http://www.correctcraftfan.com/diaries/details.asp?ID=1143" rel="nofollow - Mi Bowt |
Posted By: critter
Date Posted: October-02-2008 at 12:49am
Sorry I missed this John. Yep, I have an Acme 540 now. Made a huge difference... and not just stopping the vibration. And you are correct, Reid is a pretty handy guy to know.... lots of good info there. And a really great guy. ------------- 1980 Ski Nautique 1966 Barracuda |
Posted By: jbear
Date Posted: October-02-2008 at 1:22am
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Not to worry Roger...I figured you would find this e-mail sooner or later!
john ------------- "Loud pipes save lives" AdamT sez "I'm Canadian and a beaver lover myself"... |
Posted By: HM302
Date Posted: October-02-2008 at 1:43am
|
Thanks for the compliments Chris. You have a very nice boat also. I called Holman Moody a long time ago and gave them the numbers on my motor and I think they told me it was rated at 225 but I am not 100% sure, its somewhere around there. She runs really good though, although I am not exactly sure what a accurate speed would be. My buddy had a old Master Craft with a 351 in it out on the lake a while back and I outrun him haha.
what exactly do you mean by a rigid setup? |
Posted By: critter
Date Posted: October-02-2008 at 1:49am
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I think that he was referring to running a fabricated pipe (Stainless like Tims) from the thru hull to just below the manifold. Then you would use a short rubber hose section between the manifold to the pipe.
The pipe would be welding to the thru hull and the bends would allow you to install the fabricated pipe and thru hull as a single unit. That would be my guess.. ------------- 1980 Ski Nautique 1966 Barracuda |
Posted By: HM302
Date Posted: October-02-2008 at 1:57am
| Yea that is what I was thinking and I think that is what reid was saying earlier also. |
Posted By: quinner
Date Posted: October-02-2008 at 2:00am
|
Roger Roger,
Wondering if in an I/O setup the motor itself moves at all when revved or loaded, there would not be much or any give on a rigid exhaust in such a tight area, if movement did occur I would imagine it would be transferred down the exhaust system and then to the hull. ------------- http://www.correctcraftfan.com/diaries/details.asp?ID=1143" rel="nofollow - Mi Bowt |
Posted By: HM302
Date Posted: October-02-2008 at 2:00am
| Is there anybody else that would sell quality polished stainless thru hulls and might have 3.5", I dont believe I need to go to 4" haha |
Posted By: critter
Date Posted: October-02-2008 at 2:21am
|
3.5s are not as common as the 3" and 4".
I did find these that come in 3.5: http://www.abimarine.com/HDW/PT/HDW-PT-06-Thru-HullExhaustPortwithFlapper.html - Thru Hull ------------- 1980 Ski Nautique 1966 Barracuda |
Posted By: Chopper
Date Posted: October-02-2008 at 3:10am
How about some nice over transom pipes 
That should pick up the dB level a tad. ------------- http://www.correctcraftfan.com/diaries/details.asp?ID=1540&sort=&pagenum=2&yrstart=1996&yrend=2000 - 98 Ski |
Posted By: HM302
Date Posted: October-02-2008 at 6:30pm
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I think I am going to go with 4". Do yall think this will look pretty good or will they look to big? The ones I am looking at are from Eddie Marine
and should I get with internal flappers or without |
Posted By: JoeinNY
Date Posted: October-02-2008 at 6:47pm
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You dont need no stinking flappers, your exhaust isnt really underwater. I mean if you catch water over the back when you slow down you could consider it but I wouldnt worry about them too much. I think 3 inch would be how I would go with a 302 3 inch is plenty loud. I am concerned that for optimum sound your manifolds might neck down too far, I would compare your turn downs to some of the other ones shown in the diaries maybe there were different ones, if yours are really smaller its going to knock down the noise a bit. ------------- http://www.correctcraftfan.com/diaries/details.asp?ID=1477 - 1983 Ski Nautique 2001 1967 Mustang 302 "Decoy" http://www.youtube.com/watch?v=cO5MkcBXBBs - Holeshot Video |