Old school style Tri-y headers for street SBC

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mtrhead
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Old school style Tri-y headers for street SBC

Post by mtrhead » Mon Nov 13, 2017 3:18 pm

Re-posting from 4:2:1 header post. More appropriate to post in a new thread.

What is the opinion on the old school 1 5/8's to 2.5 collector Tri-y like Dougs, Stans, Thorley's for a street 383 or 400 sbc?
Would a typical street SBC benefit from the old school Tri-y's versus an off the shelf long tube header?

Typical street example: 3200-3500 lb car, 383-400 sbc, 195-210cc heads, hydraulic roller 230's @050, stick shift, dual plane, and ignition.
Most street builds, like one of mine, have 1 5/8 or 1 3/4 full length brand x or y standard 4:1 headers with 3" collectors.

The question would be for STRICTLY street up to 6000 rpm operating range. Haven't been able to find any concrete data or tests that actually compare from around 1500/2000 rpm up to 5500/6000 rpm. None of the headers suppliers talk about the tune length of the merge point but all 3 companies look identical from pictures and they are very short primaries compared to modern 4/2/1 headers.

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Re: Old school style Tri-y headers for street SBC

Post by lefty o » Mon Nov 13, 2017 4:04 pm

i believe in general the tri-y's will be down on power across the board.

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Re: Old school style Tri-y headers for street SBC

Post by randy331 » Mon Nov 13, 2017 9:27 pm

lefty o wrote:
Mon Nov 13, 2017 4:04 pm
i believe in general the tri-y's will be down on power across the board.
They weren't down on power across the board on our EMC engine.

Randy

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Re: Old school style Tri-y headers for street SBC

Post by Walter R. Malik » Mon Nov 13, 2017 10:43 pm

randy331 wrote:
Mon Nov 13, 2017 9:27 pm
lefty o wrote:
Mon Nov 13, 2017 4:04 pm
i believe in general the tri-y's will be down on power across the board.
They weren't down on power across the board on our EMC engine.

Randy
Some people have a presumption then guess and some people have actually tested the difference :wink:
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Re: Old school style Tri-y headers for street SBC

Post by lefty o » Mon Nov 13, 2017 10:54 pm

then why dont you guys answer the mans question?

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Re: Old school style Tri-y headers for street SBC

Post by Walter R. Malik » Mon Nov 13, 2017 10:56 pm

lefty o wrote:
Mon Nov 13, 2017 10:54 pm
then why dont you guys answer the mans question?
Sorry ... my crystal ball is broken.
Every combination will present a different result.

The tendency is that with a closed exhaust there will be little difference.
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Re: Old school style Tri-y headers for street SBC

Post by lefty o » Mon Nov 13, 2017 11:03 pm

Walter R. Malik wrote:
Mon Nov 13, 2017 10:56 pm
lefty o wrote:
Mon Nov 13, 2017 10:54 pm
then why dont you guys answer the mans question?
Sorry ... my crystal ball is broken.
Every combination will present a different result.

The tendency is that with a closed exhaust there will be little difference.
#-o yet you snipe at me for saying "in general".

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Re: Old school style Tri-y headers for street SBC

Post by Walter R. Malik » Mon Nov 13, 2017 11:11 pm

lefty o wrote:
Mon Nov 13, 2017 11:03 pm
Walter R. Malik wrote:
Mon Nov 13, 2017 10:56 pm
lefty o wrote:
Mon Nov 13, 2017 10:54 pm
then why dont you guys answer the mans question?
Sorry ... my crystal ball is broken.
Every combination will present a different result.

The tendency is that with a closed exhaust there will be little difference.
#-o yet you snipe at me for saying "in general".
My post was questioning the validity of the statement, "the tri-y's would be down on power across the board" which is GENERALly not true; no personal sniping involved.

I am sorry your feelings got hurt.
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Re: Old school style Tri-y headers for street SBC

Post by randy331 » Mon Nov 13, 2017 11:13 pm

lefty o wrote:
Mon Nov 13, 2017 10:54 pm
then why dont you guys answer the mans question?
Well, we tested them on a 353 cube and a 390 cube. Both showed nice gains down below 5000-5500 or so, but the 390 lost just a bit up top, and the 353 didn't loose at all up top. Most likely a cube/power thing there with the pipe sizes.

On any street car with lower stall speeds ( less than 4500 rpm ) the try Ys would have ran better on them than the 1 3/4 x 1 7/8 dyno headers we had on it before.

Most likely on the types of engines the OP asked about they would run better on, but Walter is right too, only way to know for sure is test.

But I do believe a lot of people run too big of headers and collectors.

A 1 1/2 x 1 5/8 step 4-1 header with a 2.5" collector could have been even better on our combo, but that type of header is not very common.

Randy

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Re: Old school style Tri-y headers for street SBC

Post by lefty o » Mon Nov 13, 2017 11:19 pm

Walter R. Malik wrote:
Mon Nov 13, 2017 11:11 pm
lefty o wrote:
Mon Nov 13, 2017 11:03 pm
Walter R. Malik wrote:
Mon Nov 13, 2017 10:56 pm


Sorry ... my crystal ball is broken.
Every combination will present a different result.

The tendency is that with a closed exhaust there will be little difference.
#-o yet you snipe at me for saying "in general".
My post was questioning the validity of the statement, "the tri-y's would be down on power across the board" which is GENERALly not true; no personal sniping involved.

I am sorry your feelings got hurt.
you didnt hurt my feelings, even though thats not the way you came across. imo being disproven would have been better than the cheap shot!

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Re: Old school style Tri-y headers for street SBC

Post by lefty o » Mon Nov 13, 2017 11:20 pm

randy331 wrote:
Mon Nov 13, 2017 11:13 pm
lefty o wrote:
Mon Nov 13, 2017 10:54 pm
then why dont you guys answer the mans question?
Well, we tested them on a 353 cube and a 390 cube. Both showed nice gains down below 5000-5500 or so, but the 390 lost just a bit up top, and the 353 didn't loose at all up top. Most likely a cube/power thing there with the pipe sizes.

On any street car with lower stall speeds ( less than 4500 rpm ) the try Ys would have ran better on them than the 1 3/4 x 1 7/8 dyno headers we had on it before.

Most likely on the types of engines the OP asked about they would run better on, but Walter is right too, only way to know for sure is test.

But I do believe a lot of people run too big of headers and collectors.

A 1 1/2 x 1 5/8 step 4-1 header with a 2.5" collector could have been even better on our combo, but that type of header is not very common.

Randy
excellent. useful information.

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Re: Old school style Tri-y headers for street SBC

Post by Walter R. Malik » Mon Nov 13, 2017 11:40 pm

lefty o wrote:
Mon Nov 13, 2017 11:19 pm
Walter R. Malik wrote:
Mon Nov 13, 2017 11:11 pm
lefty o wrote:
Mon Nov 13, 2017 11:03 pm


#-o yet you snipe at me for saying "in general".
My post was questioning the validity of the statement, "the tri-y's would be down on power across the board" which is GENERALly not true; no personal sniping involved.

I am sorry your feelings got hurt.
you didnt hurt my feelings, even though thats not the way you came across. imo being disproven would have been better than the cheap shot!
I never mentioned any names or wrote anything which could even be construed as being untrue.
It was a facetious comment but, certainly not meant to be a cheap shot.
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Re: Old school style Tri-y headers for street SBC

Post by cjperformance » Tue Nov 14, 2017 12:25 am

One typical issue with an OTS triY with short primaries to clear a typical engine bay/components is when they end up with quite different length secondary pipes, if you can even up the seconday lengths this helps them out a bit everywhere.
This said when youre not talking big $ custom pipes OR many dyno tests with differing pipes then just use what fits well and use a good sized exhaust system after it. Some OTS triY have a collector thats a bit small- step it up to what exhaust size is good for the engine. It will be fine.
Craig.

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Re: Old school style Tri-y headers for street SBC

Post by bigjoe1 » Tue Nov 14, 2017 12:43 am

About 25 years ago, I used to test headers for Thorley== I tested all the popular ones on a 350 crate motor, ( 290 HP ) and the results were soo close, there was almost NO DIFFERANCE between the try y and 4 into one style- I had the try y on my own personal car. They were much easier to install, and had more ground clearance. Their biggest draw back was the price. They cost about twice or three times as much as other name brand headers


JOE SHERMAN RACING

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Re: Old school style Tri-y headers for street SBC

Post by cjperformance » Tue Nov 14, 2017 1:08 am

bigjoe1 wrote:
Tue Nov 14, 2017 12:43 am
About 25 years ago, I used to test headers for Thorley== I tested all the popular ones on a 350 crate motor, ( 290 HP ) and the results were soo close, there was almost NO DIFFERANCE between the try y and 4 into one style- I had the try y on my own personal car. They were much easier to install, and had more ground clearance. Their biggest draw back was the price. They cost about twice or three times as much as other name brand headers


JOE SHERMAN RACING
Not to mention they allow more air out of a tight engine bay as well as emit less heat into an engine bay
Craig.

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