let it breathe
 

Guys,
I was talking with Andy/Magic Medicine tonight, and he asked me if I thought the Heat engine compartment is (air) restrictive. And of course, I do. It's the MOST restrictive setup I've ever seen. How can the engines in these boats not be starved for oxygen, particularly at Havasu (where they're made?!) in 115o heat, with engine compartments another 30/40 degrees hotter?
The only intakes are on the trailing edge of the sunlounge, which looks like a vacuum area. The only other way air can get to the motor is through the side panel insets, over the gas tanks, and around the engine compartment side panels. A circuitous route at best.
This problem gets worse as the HP and CFM demands of the motors go up. Have any of you ever run with your hatch slightly open to see if you picked up RPM or speed?
Here's what I did on my Heat to get some fresh/cool air to the motor. 1st 2 pics are the billet vents I added to the front of the hatch. Last pic is one of the factory intakes. The motor is supposed to breath through this?
Steve

Re: let it breathe
 

When I rebuilt my rear hatch to clear the intercooler, I added another rear air intake "dedicated" to the flame arrestor and throttle bodies. I tried to make this one the same size as the 2 factory intakes for continuity.
This gives me 5 intakes, and they do seem to be helping.
I got rid of my ski pole by replacing it with a round transom light. I like monstaa's piece below better, providing it doesn't leak on the distributor or wiring (shouldn't on this 35 with twins/with a single in a Heat?).

Re: let it breathe
 

I think Monstaa did some very good work on Sick Nordic's boat too. These deck side intakes are in a high pressure area that should force some cool fresh air into the engine compartment. I like his ski pole intake too.
Have any of you guys done something like this?
Regards,
Steve

Re: let it breathe
 

Yes this set up on Sick Nordics boat (here at our shop) works very well. You can also order the set from us as well.

Re: let it breathe
 

If you keep convincing me Steve I may have to try a little something on my Buddy's boat with my old motor.
We haven't had any issues thus far and we are turning 548 ci at 6000 rpm approching the century mark (95.5). (At Havasu BTW)
I am installing an R-Tech Supercooler in the the next few weeks and we are hoping to eclipse that magic number. If we don't achieve that number maybe I'll take the hatch off and see how it works :evilb: :evilb:

I can see it keeping temps down but then again, when we're in the sticks there's not much hot ambient air in the compartment for more than a second or so :D :D

Keep us posted,
Dave
(have you actually seen any gains by adding vents?)

Re: let it breathe
 

Steve,

It was great talking to you last night. Both set ups look great and would be a great addition to the air straved engine compartment on the Heat.

Re: let it breathe
 

Dave,
You know we don't like bull**** here, just objective data :D ...
my only "testing" was cracking the hatch, to see if the boat picked up RPM or speed. It did seem to gain RPM. Nothing earth shattering, maybe 50/100 RPM. BUT, this was done in the early Spring, March as I remember. I do think that in hot summer air, it would help even more. I did not do before and after testing on the vents I installed.
Another 28 Heat friend here ('96/with 800HP blower motor) did the same on his. On his earlier version, the strip where I installed my vents is part of the seat, not the hatch. So, it will work on early (95/99) Heats, and newer (2000+) models.
He says "it seems to help my boat", and when riding in my back seat says "I can feel the motor drawing air, there is definitely a vacuum effect going on".
BTW: Those are huge #s on your buddy's Heat. Is that the "light boat" we were talking about last Fall? What does the dyno say? Sounds like some big #S. Keep us posted on your progress and some pictures would be great!
Regards,
Steve

Re: let it breathe
 

Yes, It's the light boat.
We may have to do some mods anyway to fit the Supercooler. Won't know til we start though. We may gain some additioanl air access with just making it fit. By the measurements it should be OK though.
No dyno numbers but the ECM reads back well into the 900s on fuel usage.
Hopefully that's going to increase.
His X dimension is the same as the rest of ours so it has to be a weight related situation. The boat is all over the place at high speed with the 5 blade which seems odd as well. My Heat liked it. It likes the labbed 30 Bravo with a little extra cup at high rpms (centrifigul hp ;o). This is one he bought from Linster that was previously modified a bit.
He'll be buying a lab 32 here quickly.
Who knows :rolleyes:

Re: let it breathe
 

Andy,
Same to you. I hate to see you sell that beautiful Heat. If my friends DON'T buy it, they're missing "THE boat" :D .
Best Regards,
Steve

Re: let it breathe
 

Dave,
What kind of gearcase are you running? Mine seems happy with both props and the IMCO.
Tabs may help settle it down.
Regards,
Steve

Re: let it breathe
 

Steve,
He's running a standard gearcase. Mine was teady as rock with the same gearcase (literally) and 5 blade but I was a touch slower.
His is rock steady at the high speeds with the labbed Bravo.

We dropped the whole drive off at Max Machine on Friday and they called and said the forward gear was showing some pitting. He will be replacing the gear set and bearings. This Max drive has handled the abuse for 3 years so another 3 would be great.
May quiz you on the tabs and your results when you get a minute.
Dave

Re: let it breathe
 

Steve,

You got any more pics of your boat, profile engine compartment etc. The colors look sick! I love purple and yellow together.

Re: let it breathe
 

Andy,
Here's the engine compartment and some on the water.
Regards,
Steve

Re: let it breathe
 

Did the 575 fit under the standard hatch? I see you made a insert. How did you do that?

Re: let it breathe
 

Linster,
The original factory hatch is a 2 piece unit. The lower half had a cutout to fit the flame arrestor, so it did have an "insert".
It would not close with the Whipple intercooler, which is only 1 5/8"s taller than stock, so I framed the hatch halves apart with stringers, and opened up the rear for the extra breathing.
A side benefit is my sunlounge is flatter and more comfortable.
Just found these pics taken during the project.
BTW, a slick looking Harwood scoop, mounted low and painted to match the the boat, would have been cool too.....probably better from a performance standpoint. But I prefer to keep 'em guessing :rolleyes: :D , and the wife and her friends wouldn't have liked the "speed bump". I think this is a good compromise.
Regards,
Steve

Re: let it breathe
 

I ran with the hatch raised a bit when I had my 2000 Heat with a 496HO during a summer day, made no difference. Maybe it's because it's a dinky motor, but I gained nothing.

Re: let it breathe
 

Steve, can't tell the difference in running my 35 with hatch raised, however, I do it from time to time cause it make the engines sound cool.

I vented my 1995 28 the same way gained a lot of engine noise in the cockpit at running speed.


Your boat looks awesome!

Re: let it breathe
 

Gary,
Thanks. I definitely have more engine noise in the cockpit, but it's a great noise :D ..........sounds like a F-16 spooling up with the blower whine.
At low speed I hear exhaust. At midrange speeds, I hear blower whine. At high speed (unless I have the deflectors up), all I hear is wind.
Regards,
Steve

Re: let it breathe
 

Steve,

Sold a new Heat to one of your Nashville brothers. Boat should be delivered early April, very cool graphics.

Re: let it breathe
 

Steve,

Those graphics are sweet. I love the combination, one of the best looking Nordics I have ever seen!!! Awesome boat!!!

Re: let it breathe
 

Way to go Gary,
That makes 5 Heats here in Nashvegas. We're taking over :D ................
Who's the lucky Captain?
Regards,
Steve

Re: let it breathe
 

Andy,
Thanks. I've been pitching your boat to some friends. Have you heard anything from them?
Regards,
Steve

Re: let it breathe
 

Linster,
Here's how the hatch looked from the bottom (engine compartment) side, "stock". You can see the large oval cutout in the bottom half done at the factory.
If you look closely, you can see the billet intakes installed in the bottom purple strip of the hatch.
AND, if you look at the side of my buddy's Fountain, you'll see a nice air intake on the side of the deck!
Steve

Re: let it breathe
 

I like the way fountain does therer air intakes, Nordic could add easy with a few modifications. I think it does make a difference getting good air to the engine. The F1 race boats that first ran 85 with a 500EFI used forced air until it was found to be illegal. I hear they were making 3lb of engine compartment pressure at WOT by forcing air in but making all go out the engine, essentially the effects of a blower.

I really liked the 575. I wish i had a pair of them.

LLH

Re: let it breathe
 

Linster,
I saw a Velocity VR1 that had very slick ductwork. It had 4 or 5" PVC pipe glassed into both deck side air intakes, that led directly to the flame arrestor intake of the 500EFI. May be one of the boats you are talking about. Gotta admire the ingenuity.
Steve

Re: let it breathe
 

My buddy had a 95 32 w/ 525SCs and it would pick up 150+ rpm when hatch was cracked

Re: let it breathe
 

Mike,
Thanks for your input. What 32? What kind of weather?
Thanks,
Steve

Re: let it breathe
 

32 Nordic, as you probably already know the 32 was b4 the 35. No swim platform and it wasn't a stepped hull.

He would gain rpm anytime during the summer months here in SC.

Re: let it breathe
 

Steve,
REALLY like the way you added the vents into the front of the hatch...I've been mulling over something like this all winter & was glad to see your pics & how nice it looks. A bit hard to see the details, so a couple questions: Looks like 2 vents, & rest of strip is covered with purple vinyl, correct? Who supplied the vents? Any additional ducting behind vents to direct air to intake? Thanks for info!
Jeff

Re: let it breathe
 

Jeff,
The vents are Eddie Marine thin line billets. Installation is a pain in the ass but well worth it. No ducting, just a lot of fresh, cool air. I'll post some better pics soon.
The uphoulstery strip (2000 models and newer) at the bottom of the hatch is removeable with four countersunk screws on the back side of the hatch. I carefully cut and modified it to accept these vents. Before I installed the vents to the backing, I reinstalled it and used the cutouts as a template to mark the hatch. Then I cut the front edge of the hatch to match with a holesaw (radiused ends) and a circular saw.
Installed the vents to the uphoulstery strip with tower style nuts, and reinstalled and it turned out great.
On 1999 and older models, this is MUCH easier. The same uphoulstery strip is attached to the top of the rear seat, so you only have one cut.
Regards,
Steve

Re: let it breathe
 

Steve,
Thanks for the tips! I'm very familiar with this hatch strip; my Heat is 2000, & to clear Whipple pulley I had to move the rear bench forward ~3/4in, then to make up gap between hatch & bench I fabbed a spacer strip out of 3/4in plywood (covered in white vinyl), using original as template. You're right, working with that strip is a pain! I've been thinking for a long time that the Whipple sure might like some more fresh air, & after seeing the vents in yours I'm almost certainly going ahead with it. Thanks again.
Jeff

Re: let it breathe
 

Damn steve, that really is a sweet boat. especially after what I saw under the hatch. I just may have to make a special run up there when I get back and drive back home with my brother. You're talking about engines so I'm a bit more in my comfort zone.

I was actually considering fabricating a cold air induction system for mine. cold , dense air makes more power, period. No matter how you go about doing it (scoops, vents with ducts......) The trick is not allowing your engine to breath that hot compartment air. Kawasaki (the aircraft division) developed the best system for thier superbikes which actually pressurizes the incoming air as speeds increase (a poor mans blower) Obviously you have that problem licked with that SC. I have normally aspirated 1050 holley dominators to feed and want to make sure they get the good stuff. I just have to develope a trap of some sort to prevent the twins from inhaling a bunch of water if things get too ruff.

I do have another question for you and will post it in prop talk....Casey

Re: let it breathe
 

Casey,
See Mike's comments here about your boat. He has a friend who had the same boat and evidently it needs engine compartment venting/induction as you estimated.
I was looking at Andy's, now the Hart's Heat this past weekend. I was surprised to see that the '99 and older Heats don't even have the transom/sunlounge intakes. The only way air could get to this motor was the bilge blower intake, which is about 3" in diameter. Not too efficient.
My friend Eric/EB Marine showed me a Mercury manufacturer/
dealer bulleting regarding overly enclosed/restrictive engine compartments causing poor performance and hard hot starting. So Mercury does agree that this is an issue. They say they have measured engine compartment temps from 176o to 200o. That can't be good for performance. I'll try to get him to email it to me so I can post here.
Regards,
Steve

Re: let it breathe
 

Steve,

Are the Harts going to add some vents in the rear seat? The older Nordics have zero airflow. That is pretty lame for a company the is located in the desert.

Re: let it breathe
 

Andy,
Yes, I gave Vence a billet vent like the ones I have and he is going to install it soon. I originally was going to install 3 of them across the hatch. I realized after starting the project that there is a rib in the center of the hatch that I didn't want to cut through, and that 2 was a big improvement over stock.
Steve

Re: let it breathe
 

Steve,

I am glad that Vence is installing a vent that should help keep the engine compartment cooler.

Re: let it breathe
 

Hey Mike, I was wondering if your friend has any pics of the cabin area of that 95 nordic. I have a 93 32' and after some research found it was built as a para sail boat. (the platform was never installed) As this was built as a work boat, none of the amenities were installed so I have a lot of work to do in making it a plush, liveable boat like the new Nordics. Thanks....Casey

Re: let it breathe
 

TTT,
Rage, here's an extensive thread on air intakes. This applies to Heats and Flames. The deck and hatch on the Rage is similar, so maybe this will work for you.
Regards,
Steve

Re: let it breathe
 

Sorry Casey I didn't take any pictures back in those days. My buddy went through a divorce and he is....... I don't know where he is or what state.

Re: let it breathe
 

Steve,

Where on this boat were the air inlets located? Would this work on a Rage do you think. This is along the lines I am interested in.

Bill