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which hvh carb spacer do i need

Old 04-26-2006, 11:59 AM
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Default Re: which hvh carb spacer do i need

It's about the HEAT!!!

I am trying to stay focused on the question at hand of the temps between the two materials on a marine engine. I understand that under the hood heat temp isn't as much of an issue for marine engines as it may be in an auto, BUT I would still be interested in knowing if anyone has ever conducted a temperature test using a phenolic spacer vs an aluminum spacer on a marine engine???-----for anything...just to see what the differences are?

Still, the question remains as TC has asked it:

"I have used a 1" Mr. Gasket phenolic spacer for many years and thought that the thermal barrier it provided between the intake and carb was probably as much of a gain as the extra air flow and signal it may have provided. I realize and fully agree that they are mainly a tuning tool but what about the heat??"

It's the question above that I am intersted in having answered and I think the only way it can be answered is if someone has actually conducted actuall test on a marine engine using the two different materials.

Last edited by KAAMA; 04-26-2006 at 12:02 PM.
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Old 04-26-2006, 01:46 PM
  #22  
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Default Re: which hvh carb spacer do i need

Hey guys - My ears where burning and I was directed to this thread.

I'll try to help as much as possible.

Kaama - we had talked before about the heat aspect of carburetors / spacers but I don't remember how much we really got into it.

The only applications where I really find a necessasity to use a phenolic (i prefer the 'wood type' over plastic) spacer is where the heat is extreme enough to cause issues. IE: street driven cars with heat crossovers in the intake, cramped engine quarters where the heat doesn't really escape, etc,etc. I would say 90%+ of the time I am adimant for someone to get this type is in circle track cars and non-vented street cars.

To go further, many of us in the marine world with BBC's are using quite tall single plane intake manifolds that have generous air space between the plenum + runners vs intake floor. Most of us also have a oil splash shield installed in the lifter valley. If you don't have a splash shield AND are using a tall single plane intake (like the popular Dart) then it is still really no big deal. We run low coolant temps, okay real low, and cooler engine room temps, especially when compared to autos.

Only time I've personally seen a + difference on marine engines when using the phenolic material is with dual plane intakes that HAVE NOT blocked off the exhaust crossover.

===========================
Design talk :

Carb spacers used to be a "black magic" sort of affair. HVH, myself, and other companies have started to change this. However, HVH has gone the furthest.

They have designed carb spacers for almost every conceivable combination there is. Dual plane intake with cut divider, dual plane intake with full divider, single plane intakes in 1" and 2" using a 4150 and also for 4500's, The larger 4500's, cloverleaf intake manifolds, etc,etc.

Much of the guessing is over. However, we still have choices to decide since the 4150 and standard 4500 carbs to single plane intake spacers are available in 1" and 2".

This generates some nervousness because most of us remember when experimenting back in the days of open spacers we could either see a big loss, small loss, small gain, or big gain. We all tried guessing but usually got proven wrong on the dyno and/or track.

Those days are over for the most part. Why ? How many dyno's are out there now ? A ton ! How many people own a performance motor now vs 20yrs ago and earlier ? A ton !

Data. Our best friend. Right RM ? The more people we stay in touch with and the more that do proper testing, the more valuable data we have to work with.

I'd say 70% of my spacers go to dyno owners or operators. Why? best place to try different things. Cool thing is carb spacers are easy to remove/install, therefore we have racers / enthusiasts that test 'with' and 'without.'

So, experiences shared by the majority vs the minority lead us to much better understanding and much more pertinent knowledge.

==========================================

Here's some of what I see with the 1" and 2" siingle plane Super Sucker spacers. I'll stick with the 4150 series for now.

1" perfect for 454-502 mild to healthy running up to say 6000rpm. No holes or dips in torque curve to worry about.

2" perfect for 540 or larger motors. Again, still using a 4150 carb.

Now, I want to point out, we have started to see a real nice trend in those using the Dart intake and 2" spacers on 540's and larger. What a nice combo these are ! In fact, on the wilder 540's making all there power before 6500rpm, the 4150 Dart with a 1050 Dominator and the new 2" 4500-4150 Super Sucker adapter/spacer has been an awesome marriage.

Ok, back to normal stuff.

The Super Suckers where first made about 20yrs ago. A ton of development went into them since they where designed for the top guys in racing. They have received a bunch of fine tuning since then.

Here's the deal on single plane applications:
1) Help direct air/fuel for more power and better fuel distribution. Remember, the outer runners in a single plane intake are much different then the inner one's.

2) Keep the air moving away from carb bottom. This keeps air velocity moving at this crucial area. Benefit is the carb will be able to meter a lot eaiser /better.

3) Increase actual airflow into engine. EX: my super mild 502 with HV/Brodix big single plane intake and 850BG picked up over 20cfm of air at 5200rpm. That's big !

To wrap up my usual lengthy posts - with spacers now made for more specific applications, the answers are much more clear. With the amount of feedback we receive, it makes it that much easier.

Do you choose generic ? A copy ? A spacer designed by tracing a gasket ? Or a new fangled spiral bore...........Ooops, sorry. It slipped.

If you get a spacer like these you now don't have to think about spacers anymore. No more laying awake at night or thinking during work " Do I need a spacer ? Which one's better ? Will it help or hurt ?" etc,etc,etc. Listen, I'm the same as you guys also - I do it too ! Worry about something else.

Feel free to fire questions my way. You may be suprised by some of my answers like these common one's "You don't need a spacer. " or even better yet "I don't know."

==================================
Bajarunner - not sure if I know you from elsewhere but thank you. Enjoy them.

Wobble - Don't be a stranger ! Miss seeing your posts and insights. I guess you know where I have been lately. Do you like the photos ? LOL !!!

- Scott aka CFM
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Old 04-26-2006, 03:44 PM
  #23  
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Default Re: which hvh carb spacer do i need

KAAMA, Thanks for keeping this thread alive! Scott, Thanks for your detailed response on carb spacers. Would it be the 1" super sucker that you would recommend for a fairly healthy 496 stroker using a Victor Jr with a BG 850 Mighty Demon?
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Old 04-26-2006, 06:31 PM
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Default Re: which hvh carb spacer do i need

TC - yes, 1" would be perfect.
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Old 04-26-2006, 09:33 PM
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Default Re: which hvh carb spacer do i need

are spacers not as effective in blower applications?
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Old 04-27-2006, 06:29 AM
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Default Re: which hvh carb spacer do i need

No one has posted actual results yet. What does it relate to in speed or horsepower? Thats what is the bottom line.
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Old 04-27-2006, 07:13 AM
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Default Re: which hvh carb spacer do i need

Originally Posted by excursion
No one has posted actual results yet. What does it relate to in speed or horsepower? Thats what is the bottom line.
One of the members on here (in another thread) said he picked up 18hp on the dyno with a 2"/4-hole Super Sucker vs no spacer. He had his engines dyno'd at JC PERF, but he couldn't tell me what jet changes took place if any because he wasn't there when they were dyno tested.
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Old 04-27-2006, 08:02 AM
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Default Re: which hvh carb spacer do i need

Originally Posted by iamfaster
are spacers not as effective in blower applications?
Good question. I don't have much feedback on this. Probably due to most of my customers (commercial) don't do many blower build ups.

I have had just a few reg customers use them and note better idle and such, but their on water/road testing really isn't valid info since weather/water/etc,etc conditions and testing methods aren't very specific.

So, I can not really help you on this application. I'd be making something up if I did, so I won't. Sorry.
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Old 04-27-2006, 08:36 AM
  #29  
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Default Re: which hvh carb spacer do i need

Originally Posted by excursion
No one has posted actual results yet. What does it relate to in speed or horsepower? Thats what is the bottom line.
Since boats are very different from each other and so many variables mph guesses are impossible.

Controlled tests (dyno, track tuning on same days, conditions can.)

Here is a dyno test I was a part of. I was physically there.
12/31/04

502 marine, single plane intake, 850 carb.
1st test w/spacer //// 2nd test without /// same day, times listed

RPM...2:23.38PM ft/lb...HP...CFM...3:18.30PM ft/lb...HP...CFM
2400...........490.84...227.1..294.2.........475.0 4...216.7...287.9
2600...........506.8.....250.3..312.9........495.7 2...245.3...301.5
2800..........513.24....273.6..334.4........513.20 ...273.8...322.2
3000..........507.39....289.9..356.7........510.90 ...292.1...349.7
3200..........502.25....315.5..388.0........505.18 ...307.8...374.0
3400..........506.74....328.1..400.9........504.38 ...326.1...398.1
3600..........525.04....360.5..441.7........512.91 ...351.6...423.2
3800..........544.30....394.4..482.1........530.29 ...382.5...474.3
4000..........560.91....427.9..527.2........551.57 ...419.9...482.6
4200..........572.00....458.5..571.9........561.72 ...449.1...524.2
4400..........575.39....481.4..603.4........564.79 ...473.1...555.5
4600..........574.26....502.9..641.0........565.19 ...495.1...615.4
4800..........570.68....521.5..673.0........563.23 ...514.5...662.6
5000..........560.32....533.4..720.1........548.13 ...521.9...688.6
5200..........545.68....540.7..724.6........Test Ended.......
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Old 04-27-2006, 09:12 AM
  #30  
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Default Re: which hvh carb spacer do i need

Originally Posted by KAAMA
One of the members on here (in another thread) said he picked up 18hp on the dyno with a 2"/4-hole Super Sucker vs no spacer. He had his engines dyno'd at JC PERF, but he couldn't tell me what jet changes took place if any because he wasn't there when they were dyno tested.
That was me. JC and Zul dynoed my engines with and without the 2" HVH. They are N/A's with a single plane and 1050 carbs. 18 HP gain over no spacer.

DryPipeTiger also did a dyno comparison after JC Perf recommended the HVH. His engines were dynoed with another spacer (I'm not sure of the size or type) and then with a 2" HVH. 10HP gain
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