Layson Headers

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A/MP

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Anyone use them? Same problems as all the rest?
 
abodyjoe said:
Are we talking about the spitfire copies for 3 Times the price?
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Yep. The old guy that was making them doesn't any more from what we have heard. Laysons picked them up and like Most all Mopar parts suppliers, has someone else make them.
 
Yea Harold hadn’t made them in years. And For what laysons sell them for I’d spend a little more on a set of full length dougs if I had to have headers.
 
abodyjoe said:
Yea Harold hadn’t made them in years. And For what laysons sell them for I’d spend a little more on a set of full length dougs if I had to have headers.
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I would like to see dyno results. I can imagine they are one step above 340 manifolds.
 
They were definitely better then the 73 style 340 manifolds on a friends Car. Really woke it up. Then he put tti headers on it and damn it really woke up.
 
Layson's actually has them made locally here in Washington state. They are direct copies of the Spitfire headers. I've met the builder and seen the fixture to make them.
 
I don't use them, myself, but be aware that there are two different models. One set for use with original engine installation, and a different set if using a conversion motor mount installation.
 
I've been curious about primary diameter. Every set of headers you see is made for the 318 or larger, and always start with 1-5/8" primaries. However, the exhaust port dimensions on a 273 head equate to just shy of 1-1/2" circular. I have only seen 1-1/2" primaries on headers for the V8 Dakotas, but I think those are magnum heads? Anyway, since I have no interest in trying to turn my 273 into a screamer, I just want the better torque of appropriately sized primaries.

Until, then I will keep my stock manifolds.
 
Matchpik said:
I've been curious about primary diameter. Every set of headers you see is made for the 318 or larger, and always start with 1-5/8" primaries. However, the exhaust port dimensions on a 273 head equate to just shy of 1-1/2" circular. I have only seen 1-1/2" primaries on headers for the V8 Dakotas, but I think those are magnum heads? Anyway, since I have no interest in trying to turn my 273 into a screamer, I just want the better torque of appropriately sized primaries.

Until, then I will keep my stock manifolds.
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"Blither blither".... whoa hold on a second.
Where did you get the idea that you would want or need a 1 1/2 primary tube header ?
*The 318 ports are the same
*you'll actually only lower peak torque and hit it sooner in the rpm range.
 
MOPAROFFICIAL said:
"Blither blither".... whoa hold on a second.
Where did you get the idea that you would want or need a 1 1/2 primary tube header ?
*The 318 ports are the same
*you'll actually only lower peak torque and hit it sooner in the rpm range.
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Well, it all started with an article in Hot Rod, which was "10 Steps to Power", and they suggested that on a daily-driven street car, moving down a step in primary header tube size would yield more real-world power on the torque side of things, since focus would not be on top-end on city streets. They suggested on a typical SBC, to move down to 1-1/2" primaries to get that torque at a lower portion of the RPM range, as you mentioned. I agree with this, especially on a 2-barrel powered 273.

I'm not engineer, but wouldn't increasing the primary tube size to something which is larger than the exhaust port equivalent be a detriment to the motor unless, you are going for high rpm?

Matthew
 
Matchpik said:
Well, it all started with an article in Hot Rod, which was "10 Steps to Power", and they suggested that on a daily-driven street car, moving down a step in primary header tube size would yield more real-world power on the torque side of things, since focus would not be on top-end on city streets. They suggested on a typical SBC, to move down to 1-1/2" primaries to get that torque at a lower portion of the RPM range, as you mentioned. I agree with this, especially on a 2-barrel powered 273.

I'm not engineer, but wouldn't increasing the primary tube size to something which is larger than the exhaust port equivalent be a detriment to the motor unless, you are going for high rpm?

Matthew
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Exhaust port velocity with a 273 head is different than with a 350 head ... and some of those smog heads had tiny exhaust ports foremost which is why the 1 1/2 was considered. A lot of things influence the exh tract, like back pressure and it's ultimate choke hold, so consider that. Don't short yourself being overly conservative on primary diameter at this level, 1 5/8 isn't small or big.
 
Matchpik said:
Well, it all started with an article in Hot Rod, which was "10 Steps to Power", and they suggested that on a daily-driven street car, moving down a step in primary header tube size would yield more real-world power on the torque side of things, since focus would not be on top-end on city streets. They suggested on a typical SBC, to move down to 1-1/2" primaries to get that torque at a lower portion of the RPM range, as you mentioned. I agree with this, especially on a 2-barrel powered 273.

I'm not engineer, but wouldn't increasing the primary tube size to something which is larger than the exhaust port equivalent be a detriment to the motor unless, you are going for high rpm?

Matthew
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I will kind of side with You on this, but one thing to remember is that exhaust tubing incl. header thin-wall is sized by OD, not ID. So the ID of 1&5/8" header tubes is damn
near 1&1/2" anyway if You want to go by port CA. The other thing to consider is that if You should decide to amp-up the program, a good set of 1&5/8" headers can put
a car like Yours in the low 12's, maybe high 11's,...You know the saying,..do it right once and........................................................
 
Killer6 said:
I will kind of side with You on this, but one thing to remember is that exhaust tubing incl. header thin-wall is sized by OD, not ID. So the ID of 1&5/8" header tubes is damn
near 1&1/2" anyway if You want to go by port CA. The other thing to consider is that if You should decide to amp-up the program, a good set of 1&5/8" headers can put
a car like Yours in the low 12's, maybe high 11's,...You know the saying,..do it right once and........................................................
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That is a good point, and something I hadn't considered. General consensus I get is headers don't do anything for an engine that wasn't designed with performance in mind, except change the exhaust note. (With obvious exceptions being manifolds that were a bottleneck in the first place.)
 
Matchpik said:
That is a good point, and something I hadn't considered. General consensus I get is headers don't do anything for an engine that wasn't designed with performance in mind, except change the exhaust note. (With obvious exceptions being manifolds that were a bottleneck in the first place.)
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I would have to disagree with headers doing nothing for a stock engine. Getting burnt fuel out allows unburnt fuel in. Take the stock logs on an early A and replace with a header and you will feel it even with a 2 barrel.
 
Matchpik said:
That is a good point, and something I hadn't considered. General consensus I get is headers don't do anything for an engine that wasn't designed with performance in mind, except change the exhaust note. (With obvious exceptions being manifolds that were a bottleneck in the first place.)
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Yeah, don't get too hung-up on the "flow/cross-sectional area" on this, it is the headers ability to isolate the pressure-waves and subsequent rarefactions of each cylinder
that make them effective. While it's true if You're going to putt around in Your 273 and never see the high side of 5K a set of 1&1/2" OD tubes will be a great torque boost,
a set of 1&5/8" tubes aren't going to "kill" that effect by any means, but idle-2500 may be a tad less...You do have less ci./cyl. than a 225 Slanty after all!!
As far as headers and flow goes, Ya might want to watch this.................
 
A/MP said:
This is for a 273.
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yess not them hooker sucks have 2 340 6 packs my money is mine relied on hooker they suck put 2 sets on 68 cuda last one worked and my money. u dont like u spend my money...................
 
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