Worth the trouble

Automotive powered airboat discussion.
Basin_Runner355
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Worth the trouble

Postby Basin_Runner355 » Wed Oct 10, 2018 9:44 am

Last year i blew my motor stock zz4 350 melted a few pistons the works. Well i had to rebuild it on a budget well changed fully forged internals. Bored out .040 over cam roller rockers up top. Only thing i kept was the zz4 intake and heads had the heads worked. I was told only thing keeping me from making more power is the intake. So i finally saved up a lil more money and was gonna get a set of long tube headers form alumit texh and get a different intake was leaning toward the RPM Air gap. Open to suggestions my motor puts out 410hp and 435 torque as it sits i had it dyno tuned so wouldn’t be no fake numbers as to where i was at. Would a intake make that much of difference worth the Hastle of tearing it apart and putting it back together.
14ft diamond back mild zz4 355sbc pushin 410 hp 430 TQ 2:1 belt drive reduction with a 78 water walker falcons pitched at 5200

hdsadey
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Re: Worth the trouble

Postby hdsadey » Wed Oct 10, 2018 12:13 pm

What rpm was the peak power made at? The ZZ4 intake is probably only good to 5500. That RPM intake supposed to make power to 6500. Should produce more power at 5200 where it looks like your pitched. I would make the switch.

And the RPM with air gap will keep the temps down in the manifold especially with a giant fan pulling air through it!
02 Predator 12' 0320 Lycoming
92 Big O 13' 302 Ford DD
99 Donzi 16 Classic 350 Vortec

Basin_Runner355
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Re: Worth the trouble

Postby Basin_Runner355 » Wed Oct 10, 2018 1:12 pm

Peak torque at 4300
Peak hp 5300
The guy that built it said that the intake is what’s holding it back
14ft diamond back mild zz4 355sbc pushin 410 hp 430 TQ 2:1 belt drive reduction with a 78 water walker falcons pitched at 5200

hdsadey
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Re: Worth the trouble

Postby hdsadey » Wed Oct 10, 2018 5:56 pm

Air gap ought to move the power band up. Whether or not that helps your situation, one of the gearbox guys should probably answer. I'm concentrating on direct drive myself lol
02 Predator 12' 0320 Lycoming
92 Big O 13' 302 Ford DD
99 Donzi 16 Classic 350 Vortec

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Slidin Gator
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Re: Worth the trouble

Postby Slidin Gator » Wed Oct 10, 2018 6:45 pm

hdsadey wrote:Air gap ought to move the power band up.

That's the key point. You are turning the prop at the limit now. It might add some torque/Hp at 5,200 that will let you add a bit of pitch, at most 5%, but probably less, call it another 15 Hp at the prop (+45 lbs of thrust). But you are going to loose torque up to the mid 4,000's which is where the machine normally spends most of it's time. So you will loose throttle response in the operating range. I consider that a bad trade off, but it's up to you what is more important.

You would need to move to a higher gear ratio (2.3) with the intention of turning the motor to higher RPM (6K ish) to gain significant advantage across the operating range.
I grew up thinking I-10 was the Mason Dixon line.
1986 Airboat Engineering Inc., 14' Marsh Master. Refreshed narrow deck, SV O-540, 72” NGQ. A Bob Stossel original.

Basin_Runner355
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Re: Worth the trouble

Postby Basin_Runner355 » Wed Oct 10, 2018 9:11 pm

I’m not really worried about throttle response I’m more worried about getting max push. I’m limited on power so I’m trying to get most out of my motor
14ft diamond back mild zz4 355sbc pushin 410 hp 430 TQ 2:1 belt drive reduction with a 78 water walker falcons pitched at 5200

Basin_Runner355
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Re: Worth the trouble

Postby Basin_Runner355 » Wed Oct 10, 2018 9:14 pm

I recently pitched my prop down to 5,000 so if i add intake and long tube headers. If i can gain 2-300 rpms on the tach at the same pitch idd be real happy. I’ve been told the long tubes them selves can get you 2-300 rpm. So along with the intake i should see at least 2-300 rpm gain at same pitch setting
14ft diamond back mild zz4 355sbc pushin 410 hp 430 TQ 2:1 belt drive reduction with a 78 water walker falcons pitched at 5200

terrible ted
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Re: Worth the trouble

Postby terrible ted » Thu Oct 11, 2018 12:51 pm

What can you make lighter? That will equate to more push.

Basin_Runner355
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Re: Worth the trouble

Postby Basin_Runner355 » Thu Oct 11, 2018 1:25 pm

Only thing i can think of would be to run aluminum water pump and a min starter but they just put a brand new high volume water pump when motor was built
14ft diamond back mild zz4 355sbc pushin 410 hp 430 TQ 2:1 belt drive reduction with a 78 water walker falcons pitched at 5200

One Eyed Gator
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Re: Worth the trouble

Postby One Eyed Gator » Thu Oct 11, 2018 3:40 pm

I just fisnshed a 6.0 with less HP than that and it will take me and 2 others and all our fishing/camping gear just about anywhere. My boat is 14x7-6 alumitec with poly. Main difference is I run a 2.68 and a 79" 3 bld R. It is pitch at about 2.5 based on the marks. I ran a 2:1 for several years but motor was maybe 285hp. I got the chance to to run the 2.68 on the same exact setup and it was like a new boat preformance wise. Boat is setup for beltbox maybe a 2.5 might be the ticket.

I could be wrong but I always thought a dual plane intake developed more torque was good up to around 5,500 and open plenum was more for top end.

Last things to me is dialing in the bottom of your boat and motor angle. I have seen boats with plenty of HP get hung up, as a boat with way less HP motors right though the same spot.

Just my 2 cents

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Slidin Gator
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Re: Worth the trouble

Postby Slidin Gator » Thu Oct 11, 2018 7:22 pm

One Eyed Gator wrote:I could be wrong but I always thought a dual plane intake developed more torque was good up to around 5,500 and open plenum was more for top end.

I think OE Gator is right here. I was thinking this was an open plenum intake. I now see these are dual plane, regular performer and air gap. Hot Rod has an article comparing a bunch of intakes, including the ZZ4 and the Performers.

Both of the Edelbrocks out perform the ZZ4 by 1.6% on torque/Hp across the range (3000 RPM & up).
The air gap shows Hp gain of 5%, non-air gap = +3% Hp.

https://www.hotrod.com/articles/dual-plane-intake-manifold-comparisons/

Basically they improve power across the range by 1.6% and extend the RPM performance band to higher RPM vs. the ZZ4. Getting more than 1.6% requires higher RPM. So this intake would actually improve throttle response across the range, with Tq/Hp increase of 1.6% at 5,300 RPM, all good, but is it enough to be worth it?

Given:
- 4,300 - 435 Tq, 356 Hp
- 5,300 - 406 Tq, 410 Hp

I assume:
- 5,000 - 410 Tq, 390 Hp

Prop Hp increase = the RPM ratio squared - (5,300/5000)^2 = 112%. To gain 300 RPM with no pitch change it takes 390 Hp x 1.12 = 438 Hp.

At 5,300 RPM you need 438 Hp, you have 410.

438/410 = 106%. You need/want 6% Tq/Hp gain, the intake gives 1.6%. What are the Long Tube headers going to add? They do need to be tuned for the 5,300 RPM goal, otherwise they may detract from the goal.

That intake will give the 6% Hp/ performance gain needed around 5,500-5,600 if you decrease pitch and spin her, (Your choice).

I agree with others that putting the boat on a diet, alternative gear and prop and prop pitch tuning are all means of improving performance worth investigating.
I grew up thinking I-10 was the Mason Dixon line.
1986 Airboat Engineering Inc., 14' Marsh Master. Refreshed narrow deck, SV O-540, 72” NGQ. A Bob Stossel original.

Basin_Runner355
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Re: Worth the trouble

Postby Basin_Runner355 » Fri Oct 12, 2018 5:51 am

OE Gator I’m not saying my boat don’t run I’m the type of guy who liekes to tinker and get evey botnof power for. Reference. Before i built the motor and messed with the boat. We got a hill we test our boats on. When i first got it i couldn’t make it to the base of the hill with out spraying. Yesterday my brother is in from over seas whent bring him a and one his podnah ride climbed it with all 3 of us and a full 50 gal tank of gas and all the other shit i keep in my boat. And the grass was just gut and it’s still very green. Idd say the hill is tuned
14ft diamond back mild zz4 355sbc pushin 410 hp 430 TQ 2:1 belt drive reduction with a 78 water walker falcons pitched at 5200

Basin_Runner355
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Re: Worth the trouble

Postby Basin_Runner355 » Fri Oct 12, 2018 6:01 am

Right before i blew the motor. With just tuning the hull i was able to run up the hill by my self with out spraying. It was a lil damp with dead grass when i did it but i still did it
14ft diamond back mild zz4 355sbc pushin 410 hp 430 TQ 2:1 belt drive reduction with a 78 water walker falcons pitched at 5200

Basin_Runner355
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Re: Worth the trouble

Postby Basin_Runner355 » Fri Oct 12, 2018 6:04 am

I played wit. Hull jacks and motor angle for 3 months straight to get the most i coins out of the boat if we just running regular ground i can run the ground with 4 ppl easy i can’t climb mount everest with them but i can moves on The ground with them
14ft diamond back mild zz4 355sbc pushin 410 hp 430 TQ 2:1 belt drive reduction with a 78 water walker falcons pitched at 5200

Basin_Runner355
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Re: Worth the trouble

Postby Basin_Runner355 » Fri Oct 12, 2018 6:12 am

Ima do the intake and long tube headers this year ima save my money and get a 3 blade next year
14ft diamond back mild zz4 355sbc pushin 410 hp 430 TQ 2:1 belt drive reduction with a 78 water walker falcons pitched at 5200

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Slidin Gator
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Re: Worth the trouble

Postby Slidin Gator » Fri Oct 12, 2018 5:46 pm

I suggest you leave pitch alone and one upgrade at a time just so you get a measurement of the improvement from each via trailer WOT RPM.

Too bad the ZZ4 intake is not cast iron, otherwise the weight difference would be equivalent to an additional 1% motor gain...

Good luck, let us know the results, always interested in how these swags line up with reality.
I grew up thinking I-10 was the Mason Dixon line.
1986 Airboat Engineering Inc., 14' Marsh Master. Refreshed narrow deck, SV O-540, 72” NGQ. A Bob Stossel original.

Basin_Runner355
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Re: Worth the trouble

Postby Basin_Runner355 » Fri Oct 12, 2018 9:32 pm

Will do
14ft diamond back mild zz4 355sbc pushin 410 hp 430 TQ 2:1 belt drive reduction with a 78 water walker falcons pitched at 5200

Basin_Runner355
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Re: Worth the trouble

Postby Basin_Runner355 » Fri Oct 12, 2018 9:33 pm

The intake will be in Monday and I’ll have to wait a week and a half for alumitech to build the headers i called today but they were out of stock
14ft diamond back mild zz4 355sbc pushin 410 hp 430 TQ 2:1 belt drive reduction with a 78 water walker falcons pitched at 5200

Basin_Runner355
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Re: Worth the trouble

Postby Basin_Runner355 » Thu Oct 25, 2018 7:50 pm

Ok got the headers put on today made a push with them and lost 100 rpms but i think it may need to be retuned / leaned out cause it kept wanting to flood out
14ft diamond back mild zz4 355sbc pushin 410 hp 430 TQ 2:1 belt drive reduction with a 78 water walker falcons pitched at 5200

Basin_Runner355
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Re: Worth the trouble

Postby Basin_Runner355 » Mon Nov 05, 2018 5:31 am

Got the intake and long tube headers on and I’m
Kinda dissapointed i did not see a single gain on the tach from both upgrades. If anything i feel like i lost power on the top end with just the headers i lost 100 rpms withbthe intake. All i did was gain back my 100 rpms so i guess in the end for total of $700 it’s not worth it the long tubes look better but i might put the shorty headers back on. I was told the long tubes are letting to much exhaust ohtbthe engine for the cam that they put in it. And I’m not paying another 6-700 for them to pull the motor and dyno tune it.
14ft diamond back mild zz4 355sbc pushin 410 hp 430 TQ 2:1 belt drive reduction with a 78 water walker falcons pitched at 5200

Basin_Runner355
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Re: Worth the trouble

Postby Basin_Runner355 » Mon Nov 05, 2018 5:35 am

I may have gained some bottom end torque it starts to break ground around 3200 rpms.
14ft diamond back mild zz4 355sbc pushin 410 hp 430 TQ 2:1 belt drive reduction with a 78 water walker falcons pitched at 5200

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Slidin Gator
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Re: Worth the trouble

Postby Slidin Gator » Mon Nov 05, 2018 9:31 am

Basin_Runner355 wrote:I was told the long tubes are letting to much exhaust ohtbthe engine for the cam that they put in it.


ohtbthe? Please use English, I don't understand, damn phone screens...

I assume you have not changed prop settings. Do you know what RPM the headers are tuned for? First guess is that they are too short to work properly around 5,000 RPM?? Making them much too short for lower RPM torque. I would test the shorty's with the new intake, I bet you gain more low end and possibly a few RPMs.

What cam did they put in the motor?
I grew up thinking I-10 was the Mason Dixon line.
1986 Airboat Engineering Inc., 14' Marsh Master. Refreshed narrow deck, SV O-540, 72” NGQ. A Bob Stossel original.

Basin_Runner355
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Posts: 166
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Location: St.martinville , Louisiana

Re: Worth the trouble

Postby Basin_Runner355 » Mon Nov 05, 2018 10:56 am

No i did not mess with the prop. As far as the headers go they are From alumitech 1 3/4 tube. With 3 inch collector. Again im not sure exactly what cam is is the engine.
14ft diamond back mild zz4 355sbc pushin 410 hp 430 TQ 2:1 belt drive reduction with a 78 water walker falcons pitched at 5200

Basin_Runner355
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Re: Worth the trouble

Postby Basin_Runner355 » Mon Nov 05, 2018 11:21 am

Wish i would have left the short ones on new flex pipe isn’t cheap $28 per ft
14ft diamond back mild zz4 355sbc pushin 410 hp 430 TQ 2:1 belt drive reduction with a 78 water walker falcons pitched at 5200

diamondback0320
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Re: Worth the trouble

Postby diamondback0320 » Mon Nov 05, 2018 12:53 pm

flexpipe $28 a ft..where you buying that.. I've never paid over$12ft for stainless


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