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Discussion Starter #1
What would you do? single plane, dual plane and tunnel ram with properly sized plenum....they all take a different firing order.

discuss..........:p and keep in mind this the max effort N/A section
 

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Throttle's Performance
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What would you do? single plane, dual plane and tunnel ram with properly sized plenum....they all take a different firing order.

discuss..........:p and keep in mind this the max effort N/A section
You could have two different single plane intakes that are designed around a different firing order and you could obviously have a dual plane intake designed around a different firing order.

The single plane, the dual plane, and the tunnel ram could also all be designed around the same firing order.

So what are we discussing? What is the question?
 

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Discussion Starter #3
Has anybody ever heard this run?
for the ford...15786432
and the chevy...15736842

BTW, its the same order
 

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Discussion Starter #4
You could have two different single plane intakes that are designed around a different firing order and you could obviously have a dual plane intake designed around a different firing order.

The single plane, the dual plane, and the tunnel ram could also all be designed around the same firing order.

So what are we discussing? What is the question?
No, you can't.....you can, but one combo will be "maximized" better than the other...(by using the same order)
 

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Long Live The King
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Has anybody ever heard this run?
for the ford...15786432
and the chevy...15736842

BTW, its the same order
yeah I've noticed before:


of all the available combinations to fire a 90* V-8 only 4 won't tear the engine apart ( or so I've been told)
 

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Long Live The King
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No, you can't.....you can, but one combo will be "maximized" better than the other...(by using the same order)
do you know how many different combinations there are to wire a V-8 distributor cap ? ( No damn wonder it's a good idea to have the firing order on the intake ;) )
 

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I have a few SBF 60mm 0.937 lifter deal with altered firing order
Haven't used yet but there a 400 and a 440 cui windsor
Sheet metal intake dual dominator
Billet headed :rolleyes:
Waiting for a few bits and pieces to finish
Let you know
 

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Discussion Starter #11
Good graphics G. So, are we talking about main bearings or how to ride a wave across the plenum? ;)
We are in the N/A section....:p
 

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Discussion Starter #12 (Edited)
from speed tech site.........

Here's a firing order that puts the pulses 90* apart, you should hear it run.
1,5,7,3,6,8,4,2


My info. on it is a bit sketchy, but i believe it originated in f1 and indy car stuff. I know it was tried by a few teams in pro-stock, which are the ones is heard run.It was amazing, if you had hearing protection. lol. It had a very high pitched scream to it that sounded like an IRL motor on steroids. I thought it was a 180* crank in them, and of course they let everyone else think that, too.From what i understand, the motors accelerated better than anything else, but the power band was very narrow. Hitting the induction/exhaust tuning was very difficult and all the teams i know of quite running it. I would still like to try it in something, just to give it a shot, but don't really have a good application for it yet

Your exactly right! That's exactly what it did. They accelerate like nothing I have ever witnessed before or since but you cant run an engine that noses over 200hp after the power peak. It just wont ET and it certainly wont MPH. I will never forget running that cam on the dyno. It sounds like a million bumble bees running around in your head and man oh man is it loud. The theory behind this is to fire intake and exhaust 90 degrees apart instead of 90 and 180 but that dead spot in the header of 450 degrees was the cause of our problems and no matter what header design
you came up with, it wouldn't work. I am sure it would work if you could come up with a header that was an 8 into one but then it would be to long! We are using 20 inch primaries now so that would be an impossibility. The thrust form the headers was another weird thing about that firing order. We had to tie down the dyno so the headers would not thrust it forward! Ferrari, Bougoti and a host of others have tried it and abandoned it.
 

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A sobering word here. For a drag race application if you want to control the wave propagation a tunnel ram is still currently the plan (IMHO) if you have the proper plenum volume to keep the runner length honest to the rpm range. If you're running a single carb the shape of the plenum top is significantly important, not only for runner length but for distribution as well.

That's my current view. It is subject to change.
 

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A sobering word here. For a drag race application if you want to control the wave propagation a tunnel ram is still currently the plan (IMHO) if you have the proper plenum volume to keep the runner length honest to the rpm range. If you're running a single carb the shape of the plenum top is significantly important, not only for runner length but for distribution as well.

That's my current view. It is subject to change.
Makes sense to me Lobes. Seems like the Ls/Ford firing order is the most common, but finding the best plenum volume and runner length is a true science. IMO carb spacers correct plenum volume in most cast single plane intakes, but starting fresh with a tunnel ram has become a application specific science.
 

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And no one is paying attention to cylinder position on the crank as in a Traditional Pontiac has number 2 as the first cylinder on the crank followed by number 1 .Manifolds are skewed towards port location.So When trying to figure which firing order will work best with crank position and its connection to intake manifold traffic it is an Apples to Oranges mateing a pass side leading cylinder FO to a driver side leading cylinder engine and vicea versa,Not to mention thermal grid considerations.Bill C.
 

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YUP GOOD POINT but the use of a good ol' hilborn or enderle port injection will solve any firing order or cross port wave interuption...with individual port for each cylinder ( no plenum)...people today have no idea why they were made this way back then...
 

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main bearings
Relative to the main's thing....I read , several decades ago, that Ford went to the 1-3-7-2-6-5-4-8 order on the 351W engine to benefit the #2 main.
I never thought of it again untill I saw the few 521"-557" BBF two bolt main blocks that had cracked from a main bolt hole to the cam bearing tunnel. They were all at the #2 main saddle.
 

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Some people say a altered firing order in a twin four sheet metal intake will make 10-20 more is the true or is it case specific
As mentioned have both but only ever run a standard clevo firing order
 
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