Intake Manifold
11-15-2014 | 08:23 AM
#21
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From: On A Dirt Floor
SB, here you go,
http://www.hotrod.com/how-to/engine/...pm-vs-air-gap/
As has been stated you may see a difference in a hot environment like under a car hood in the summer as the intake charge is separated from the hot lifter valley. Don't know if it's really needed in a boat.
FWIW, I run the air gap on my small block.
http://www.hotrod.com/how-to/engine/...pm-vs-air-gap/
As has been stated you may see a difference in a hot environment like under a car hood in the summer as the intake charge is separated from the hot lifter valley. Don't know if it's really needed in a boat.
FWIW, I run the air gap on my small block.
I've run a quazzilion of both type of intakes and studied them, obviously.
I'm doing this 'questioning' as more of a mental excersise for people. Just like to see what people assume vs actually know. And not on a matter of who's smarter than who...I don't get into that...more more of a matter to see thoughts, theories, and more importantly assumptions vs data from real world use.
That's all.
It was 26*F here this morning (prob same for you) and thus physical boating is done...but mental continues. LOL.
11-15-2014 | 08:38 AM
#22
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From: NJ
So lets change the subject and talk about a single plane manifold. 2nd part of my post. Why does the HP 500 come with a single plane verse a dual plane. Top rpm on an hp 500 is 5200- 5400 These single plane manifolds just start working at 4500 rpms and are good to 8000 rpms. My dual plane is good from 1500- 6800 rpm. Can someone explain?
11-15-2014 | 09:03 AM
#23
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From: On A Dirt Floor
#1: Cubic inches changes things.
#1.5: Manufacturer states an rpm range as help, however thry don't know if you are installing it on a 396, 454, 502, 540, 572, 598, 632 or ??? and add to those the countless different possibilities of cam heads, compression, torque converter (or direct drive), trans gear ratios, rear end (outdrive) , exhaust, and etc,etc. Not trying to make this more difficult than it is...but it all plays a part - some more important than others. cid, cam, and heads together make a massive influence on what to get.
#2: Not all single plane intake manifolds are created equal.
- Runner cross sectional area
- Runner Length
- Plenum size
#3 Who wants to see a car intake on a blue motor ?
A single plane says 'Race' and blue motors are 'mercury racing.'
Again, 500cid's with high lift cam and heads with big valves requires a bunch of air. The dart single plane 4150 intake has conservative plenum and runner sizing, so it works quite well in this application.
Put on a Super Victor or Super Victor II and things won't work out so well.
#1.5: Manufacturer states an rpm range as help, however thry don't know if you are installing it on a 396, 454, 502, 540, 572, 598, 632 or ??? and add to those the countless different possibilities of cam heads, compression, torque converter (or direct drive), trans gear ratios, rear end (outdrive) , exhaust, and etc,etc. Not trying to make this more difficult than it is...but it all plays a part - some more important than others. cid, cam, and heads together make a massive influence on what to get.
#2: Not all single plane intake manifolds are created equal.
- Runner cross sectional area
- Runner Length
- Plenum size
#3 Who wants to see a car intake on a blue motor ?
A single plane says 'Race' and blue motors are 'mercury racing.'
Again, 500cid's with high lift cam and heads with big valves requires a bunch of air. The dart single plane 4150 intake has conservative plenum and runner sizing, so it works quite well in this application.
Put on a Super Victor or Super Victor II and things won't work out so well.
Last edited by SB; 11-15-2014 at 09:10 AM.
11-15-2014 | 10:01 AM
#25
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From: NJ
ok so my 509 490 hp engine with a crane cam 547 lift 224-234 duration, oval port 781 heads with large econel valves and a nickerson custom built 930 cfm carb will have to stay with a air gap dual plane intake.
11-15-2014 | 10:54 AM
#26
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From: taxachusetts
really,,you know this as fact,,because I have a few engines that say otherwise.and a couple were 454's.and the jr's were ported for the 454's too.
I've heard this argument since 2001 when I built my 502 for my truck.w/ the boat in tow I could blow the tires off that thing,,my only regret,,putting in a whimpy azz cam 218,222 less than 600 lift.
I've heard this argument since 2001 when I built my 502 for my truck.w/ the boat in tow I could blow the tires off that thing,,my only regret,,putting in a whimpy azz cam 218,222 less than 600 lift.
11-15-2014 | 11:02 AM
#27
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From: taxachusetts
11-15-2014 | 11:12 AM
#29
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From: On A Dirt Floor
really,,you know this as fact,,because I have a few engines that say otherwise.and a couple were 454's.and the jr's were ported for the 454's too.
I've heard this argument since 2001 when I built my 502 for my truck.w/ the boat in tow I could blow the tires off that thing,,my only regret,,putting in a whimpy azz cam 218,222 less than 600 lift.
I've heard this argument since 2001 when I built my 502 for my truck.w/ the boat in tow I could blow the tires off that thing,,my only regret,,putting in a whimpy azz cam 218,222 less than 600 lift.
I did not mention Vic Jr's.
I wrote Super Victor and Super Vic II's.
Way different manifolds - other than being single planes.
