Torque & HP Open Discussion |
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81nautique
Grand Poobah Joined: September-03-2005 Location: Big Rock, Il Status: Offline Points: 5768 |
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GottaSki, I'll play around with that in the next few days but I'm sure I'll have some questions so stay tuned.
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You can’t change the wind but you can adjust your sails
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Waterdog
Grand Poobah Joined: April-27-2006 Location: United States Status: Offline Points: 2020 |
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Alan
I've been holding on to a set of cracked exhaust manifolds, to cut open. Would you cut it front to back, thru the center of the pipe plug holes on each end ? Just wondering what would be "best". |
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81nautique
Grand Poobah Joined: September-03-2005 Location: Big Rock, Il Status: Offline Points: 5768 |
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That's what I was thinking of doing so we could get a look at the runners up to the riser. I also plan to port match mine when I get my heads in so I wanted to see how much material there is to work with. |
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You can’t change the wind but you can adjust your sails
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GottaSki
Grand Poobah Joined: April-21-2005 Location: NE CT Status: Offline Points: 3333 |
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most excellent. look forward to it. Likely those heads will like more cam lift than you are used to seeing. Most windsors reach deminishing returns above .45", but it appears the canted valves really open up and get away from the cyllinder wall from .45" on up and the flow continues to climb in earnest. |
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"There is nothing, absolutely nothing, half so much worthwhile as messing around with boats...simply messing."
River Rat to Mole |
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Waterdog
Grand Poobah Joined: April-27-2006 Location: United States Status: Offline Points: 2020 |
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Alan
I'll get those exhaust manifolds out of the barn & put them in my work car. I'll cut 1 if I like it I'll cut the other the same and ship it to you. Probably just the inboard half to cut down on weight. Could you donate the cost of shipping to the club ( CCFan)? |
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81nautique
Grand Poobah Joined: September-03-2005 Location: Big Rock, Il Status: Offline Points: 5768 |
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That will work Andy, do you have a bandsaw at your disposal? I wasn't really looking forward to tackling this with just a sawzall. |
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You can’t change the wind but you can adjust your sails
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Sabre002
Groupie Joined: July-18-2007 Location: United States Status: Offline Points: 53 |
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This program is great I showed it to Reid a few years ago I have sense got a new version and you would not belive the thing it will let you toy with.
I have used it to build my LS1 and it was right were it said it would be. |
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So what winks and f**k's like a tiger?
www.facebook.com/sabre002 |
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Waterdog
Grand Poobah Joined: April-27-2006 Location: United States Status: Offline Points: 2020 |
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Alan
I pulled the manifolds out of the barn last night. Need to remove the risers and throw them in the trunk. We have a 20 in cut off saw at work for sectioning aircraft parts during engineering investagations. Maybe over the weekend I'll come in and cut them up. |
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81nautique
Grand Poobah Joined: September-03-2005 Location: Big Rock, Il Status: Offline Points: 5768 |
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Cool, I'm really interested to see how these things are shaped. Please send both halves if you can. I have a neighbor at my shop that does hydraulic flow testing for nuclear power plant cooling systems and started a conversation with him yesterday about the manifolds and he said once I remove mine for the upgrades he could help me set up a flow test on them. When I was in the window industry I had to take a sampling of each of our products to a test lab annually so we could have water and air infiltration tests performed for certification so I have a pretty good idea of whats going to be needed to do it. Should be fun putting the rig together. |
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You can’t change the wind but you can adjust your sails
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M3Fan
Grand Poobah Joined: October-22-2005 Location: United States Status: Offline Points: 3185 |
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Although the riser area is a bit restrictive doesn't the length of the restriction become a factor as well? For example, an automotive header may be less restrictive at the collector but then you've got 2" exhaust going all the way back to the rear of the car with twists and turns, cats, mufflers, resonators, etc. With a lot of these boats you've just got 10 feet or so of 3" hose and nothing else to restrict flow after the riser.
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2000 SN GT40 w/99 Graphics/Gel
2016 SN 200 OB 5.3L DI https://forum.fifteenoff.com |
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8122pbrainard
Grand Poobah Joined: September-14-2006 Location: Three Lakes Wi. Status: Offline Points: 41040 |
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Joel, Very good point!! With some CFM figures, it's very easy to look on the graphs or calculate the restriction with different lengths and diameters of "tail" pipe. My graphs will show restriction in inches of water (manometer reading). I'll take a look to get a rough idea. The major unknown however will be the effect of the water in our wet exhausts.
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81nautique
Grand Poobah Joined: September-03-2005 Location: Big Rock, Il Status: Offline Points: 5768 |
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While flow of the exhaust system is one concern another major factor that will not be overcome with stock manifolds is that they are considered a Non Tuned design meaning no pulse or suction waves are produced so there is absolutely no scavenging effects to help evacuate exhaust gases from the cylinder. You would need to get into a header/collector design and I don't believe even the hiteks fall into this catagory as they are not long enough. So restriction may not be as big a detriment as overall design. Let's not forget about the water in those 3" pipes and the effect it may have as well. |
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You can’t change the wind but you can adjust your sails
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81nautique
Grand Poobah Joined: September-03-2005 Location: Big Rock, Il Status: Offline Points: 5768 |
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Thinking about this exhaust a little more, without scavenging, the engine is relying solely on the exhaust stroke of the piston to push the gases out of the cylinder. This also has an impact on the engines ability to refill the cylinder with a fresh charge of intake mix. Scavenging in combination with valve overlap could be the biggest factor in get air/fuel and spent gases through our engines. Scavenging creates the pulse and overlap allows the intake and exhaust valves to be open at teh same time using the pressure of the outflowing gasses to draw in fresh air/fuel mix. If that effect is being limited then the focus should still be on the exhaust.
Seems to me we need water jackets headers for a ski boat. |
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You can’t change the wind but you can adjust your sails
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Hollywood
Moderator Group Joined: February-04-2004 Location: Twin Lakes, WI Status: Offline Points: 13511 |
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Alan, what has gotten into you? You can still ski, plenty of "golden" years to do all that engine stuff.
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81nautique
Grand Poobah Joined: September-03-2005 Location: Big Rock, Il Status: Offline Points: 5768 |
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I don't know man, been hanging around with these motorheads for a couple of years and I'm hooked. Don't worry though, I still get Amped to go skiing but the head ringers seem to take longer to go away. Ended my last footin run of the year sunday with a big crash and the birdies didn't go away for an hour and I limped around until wednesday.!!! |
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You can’t change the wind but you can adjust your sails
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81nautique
Grand Poobah Joined: September-03-2005 Location: Big Rock, Il Status: Offline Points: 5768 |
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ok, last post for this morning, I gotta get out and make a living.
I took the last dyno on my engine with the new mods and then ran another one but replaced the stock exhaust and mufflers with short tube headers and mufflers. The results are below and quite dramatic. My engine on the left and the Header engine is on the right. |
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You can’t change the wind but you can adjust your sails
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Brktracer
Senior Member Joined: December-20-2007 Location: South Carolina Status: Offline Points: 387 |
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Amen! ...still thinking of trying a set of headers! Any predictions? |
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JoeinNY
Grand Poobah Joined: October-19-2005 Location: United States Status: Offline Points: 5693 |
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Matt, I dont think the hiteks weight is prohibitive to shiping, someone here has the number it is in the 10-20 lb each range. I will try and pull out my dyno sheet and get specifications to alan here so we can run mine and see how close we can get to what the dyno measured... lots to talk about here but I am late for a meeting... |
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RainDog
Platinum Member Joined: February-21-2007 Location: Mke/Grn Lake WI Status: Offline Points: 1387 |
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Alan,
Would your buddy be willing to flow a Hi-Tek header as well? It would be interesting to see if it flows any better and by how much. |
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81nautique
Grand Poobah Joined: September-03-2005 Location: Big Rock, Il Status: Offline Points: 5768 |
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Steve if we can get a bench rigged up for very little money I'd be willing to test anything. The neighbor uses all digital monometers and he's not sure if the boss is going to let them be loaned out. Still working on it thought. I just picked up a set of HM manifolds on ebay last night so those will go on the list as well. |
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You can’t change the wind but you can adjust your sails
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8122pbrainard
Grand Poobah Joined: September-14-2006 Location: Three Lakes Wi. Status: Offline Points: 41040 |
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I wish we had a means of measuring the resistance of our wet tube exhausts and then comparing them to the automotive exhausts. The water bouncing around in the "tail" pipe I'm sure adds up. |
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Brktracer
Senior Member Joined: December-20-2007 Location: South Carolina Status: Offline Points: 387 |
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Alan: Glad you found some HM manifolds. I look for them periodically but have yet to see a set for sale. Any idea when you might test them? Pete: You make a great point about the water. I'm betting the amount of water we are pumping through the exhaust is overkill as well. But, that's probably not an area to fool around with unless we are very careful! Matt |
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81nautique
Grand Poobah Joined: September-03-2005 Location: Big Rock, Il Status: Offline Points: 5768 |
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I don't want to pull anything apart until all my parts are in and that looks like mid november. I wasn't sure I wanted to go with the HM's but they showed up with a low buy it now so I scooped them up. Hopefully this will also solve the taller valve cover issue that I had with the PCM's. Ofcourse before they go on I'll have to polish them!! |
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You can’t change the wind but you can adjust your sails
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boat dr
Grand Poobah Joined: June-27-2004 Location: United States Status: Offline Points: 4245 |
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Allen , give me a call . I may have some pieces to add to this maze.
Boat dr 1-318-386-2825 |
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Luchog
Grand Poobah Joined: April-17-2007 Location: Argentina Status: Offline Points: 2135 |
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how would the Commander manifolds flow comnpared to others? I'm about to buy an engine with these. My boat uses some square log type replacements.
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JoeinNY
Grand Poobah Joined: October-19-2005 Location: United States Status: Offline Points: 5693 |
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I see no reason why the commanders (at least 3 inch outlet commanders) wouldnt flow as well or better than the holman moody ones. They are extremely similar manifolds without the up and down riser. I am also not convinced that the pcm manifolds aren't better or equal to both the commanders and the HM's, although they are much quieter. Absolute flow will not be the only determination. A lot of the marketing around the PCM pyramid design was related to the effective "runner" length of the PCMs' being much more equal between cylinders than the log style manifolds. It may all be bs but it is something to consider, logs definitely dont help with scavenging. The stock PCM configuration supports a lot of horsepower in the GT'40's and other later engines. The python engines do pretty well with PCM manifolds that dont look a heck of a lot different than the sbf ones. So my plan was to test my commanders vs hi-teks vs pcms on the same engine here in the fall (not a great test anyway because its not a stock displacement engine), but since my boat is down once again thats not going to happen. However I do have a set of commanders I could ship out with those hi-teks if someone really wants to get some water testing in... |
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Mojo
Grand Poobah Joined: December-06-2006 Location: United States Status: Offline Points: 3104 |
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Magic,
I have the manifold in the shed. I'll bring it Thursday. Hope you can still make it for beers... Moj' |
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05' SV211 TE
73' Martinique had:96' SNOB had:76' Nautique had 77 Tique |
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MaddMarxx
Platinum Member Joined: June-29-2006 Location: United States Status: Offline Points: 1741 |
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Maybe if I put this on my Boat I may be able to give Reid a run for his money!!
471 Blower |
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81nautique
Grand Poobah Joined: September-03-2005 Location: Big Rock, Il Status: Offline Points: 5768 |
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Well Andy(waterdog) has finished his monumental task of sectioning a PCM manifold and it is on it's way to me. I'll post a few pics once I get it and maybe we'll bump some life back into this thread.
I've started dismanteling my Holman Moody manifolds but they haven't been apart in 40 years and they're kicking my butt. Finally had to give in to the hacksaw and cut the risers off. It's obvious why these went in the trash as the internal mating surfaces were not sealing and this boat must have been hyrolocking with all that water leaking in. A trip to the machine shop to remove the studs(I gave up on that too) and resurface them and I'll be back on track. After that we'll make teh adapter plate for the A/F sensor, then get back to cleaning and polishing them up. Probably won't get to any flow comparison testing between the HM and the PCM for a while yet but it's still on the list. Doc, I 've had a pretty busy week and never did find the time to call so if you care to post your engine specs online here I'll run a dyno for you. |
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You can’t change the wind but you can adjust your sails
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8122pbrainard
Grand Poobah Joined: September-14-2006 Location: Three Lakes Wi. Status: Offline Points: 41040 |
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The blatantly obnoxious advertising posting of the Hitek manifolds by Ash has gotten me thinking about their design again. Allen, I believe you made a comment that they really aren't a true "header" design and I certainly agree. The performance gains are probably due to the smoother and larger porting. It's a shame Hitek didn't carry the design farther with continuing the water jacketed exhaust tubes down the aft side and to a collector closer to the bilge duplicating a true header. Most of our engine enclosures have the room to do it. The only issue would be keeping the low side of the water jacket full before the collector. Certainly not a very difficult problem with a block off plate on the high side of the existing and then hosed to a bottom fill on the tail end. Up the tail end to another outlet hosed back to the far side of the collector.
As far as flow of the existing design, it's too bad Allen couldn't check them out with his flow bench he's building. I feel we should ask Ash to plug up all the ports on a set, strap them to his back as "water wings" and swim them over!! |
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