Who can build a set of 351w headers 2” primaries 3.5 collector without truck?

J

joshdillon

Shuamanator
Hello! Anyone running Kooks 2” primary headers part # 10241650 for a 351w Mustang in a Gen 1? Will they fit?

My engine builder tells me we need bigger exhaust primaries to support 20psi. The head is trying to lift and the burn marks in the cylinder shows insufficient exhaust flow. Current combination in Gen 1 truck:
Dart 351w stroked to 422
Trick flow 61cc 206cc R heads with Box R intake and 75mm TB (upgrading to 90mm)
1 7/8” Accufab Mustang 351w mustang long tube headers
Vortech YSI-B

Trick Flow Race Heads Flow
Part no. 52410005-M61
R head flow rate I/E
Actual @28"
.400 245.6/196.7
.500 284.3/252.4
.600 311.9/267.1 (84% is 262)
.700 323.6/275.2

Corrected
.400 238.9/189.6
.500 276.2/241.1
.600 303/253.8 (84% is 254.52)
.700 314.3/260.7

I would think the 1.6 exhaust valve would be the restriction and 1 7/8 primaries should support plenty more than current 800 wheel. Been searching for days and Kooks seems like the only option vs custom headers and they can’t tell me if they will fit the gen 1. Kooks is no longer building custom headers.

Who else can build a set of 2” primary x 3.5 collector headers for 2.75 exhaust pattern without having truck?


Sent from my iPhone using Tapatalk
 
Did you call Kooks to see if they can make the same headers you have but in the size you need?
 
Hi Josh, I’ve been talking to Kooks (Charlie Caison) via email about larger headers for our trucks. He wants me to call and talk more after I sent a bunch of pics, but that’s tough for me as I am in meetings all day. As soon as I can I’ll let you know what they say.
 
You guys are always awesome with quick replies!

So, I just talked with Charlie at Kooks a couple hours ago and he couldn’t confirm if the mustang headers would work:

10241650 mild steel 2 3/4 diagonal pattern

He talked to the owner and then came back and suggested buying flanges and a tube kit to build your own:

Header build kit:
qty. 2 3/8 flanges 7022-S-0410
Qty. 1 (both sides) 2” tube and 3.5” collector kit WK2650

Not really something for which we have time and experience.

I was thinking about doing a buy in with Kooks, but would definitely want a set for my own truck. Also, I had a long conversation with George K today and he is under the impression Kooks is no longer doing any custom builds like before.
Wonder how many of us would be interested if we could get Kooks to build a set?
How many sets they would require?


Sent from my iPhone using Tapatalk
 
I’m in, but I have straight bolt pattern. Josh, so they don’t do any cut stuff like they wouldn’t want us to bring a truck?
 
I had Kooks build me a custom set of headers for my truck a long time ago when they were located in Long Island. It was very expensive but we’ll worth the money. Maybe someone could work something out with them to have a truck there and have a bigger option designed for the guys who need them.
 
Jamie V said:
I had Kooks build me a custom set of headers for my truck a long time ago when they were located in Long Island. It was very expensive but we’ll worth the money. Maybe someone could work something out with them to have a truck there and have a bigger option designed for the guys who need them.
Click to expand...

Exactly, that's where I was going. I LOVE how my headers fit and am willing to pay for that along with their quality. I'd trailer the truck up there and let them use it to build a nice set and get templates for a larger tube diameter.
 
Agreed. I’d be willing to pay up to 2k for a nice set of stainless 2”, but if it comes to paying 3-4k for a custom built set, I’d go turbos.

Talking with another friend today, his engine builder thinks my issue with the head trying to lift is tune related and the current 1 7/8s should be fine with 20 psi in the 800-900 wheel range. Plenty are running 1 5/8 turbo headers making 1000.

We are definitely at the limits of the treadstone ic which claims to flow 1950cfm.

Anyone have any thoughts about tune / intake temps causing head to lift VS exhaust being too small?


Sent from my iPhone using Tapatalk
 
Might as well start planning those turbos LOL. Hell the Kooks off the shelf headers are something like 14-1500 now.

I’m no engine builder, so my opinion is useless, but I have a hard time believing you’re lifting the head due to 1 7/8 headers. Now high intake temps are another matter, that’ll cause detonation and definitely pop the head gaskets or worse. What IATs are you seeing? Also you could add a pre intercooler temp/pressure sensor if you wanted to get fancy so you can verify the intercooler is no longer efficient.
 
You also have to consider the cam if your heads are lifting. You could have too much cylinder pressure and the cam might not be bleeding enough off.
 
joshdillon said:
Agreed. I’d be willing to pay up to 2k for a nice set of stainless 2”, but if it comes to paying 3-4k for a custom built set, I’d go turbos.

Talking with another friend today, his engine builder thinks my issue with the head trying to lift is tune related and the current 1 7/8s should be fine with 20 psi in the 800-900 wheel range. Plenty are running 1 5/8 turbo headers making 1000.

We are definitely at the limits of the treadstone ic which claims to flow 1950cfm.

Anyone have any thoughts about tune / intake temps causing head to lift VS exhaust being too small?


Sent from my iPhone using Tapatalk
Click to expand...
I know I lifted the heads on my truck with novi 2000 pushing 23# of non intercooled boost on stock bottom end lol. No detonation but my intake temps were 250+ degrees. I just exceeded the clamping power of the arp head bolts I used. Put head studs in with better cometic gaskets and went turbo with a good intercooler. I doubt the exhaust has anything to do with anything.

Sent from my Pixel 6 Pro using Tapatalk
 
I agree with Raymond. If a turbo combo can run 1 5/8" shorties and have more drive press in the exhaust than boost on the intake - 22psi - side and have NO head gasket probs,I don't see an NA combo having a prob.
 
You must log in or register to reply here.
Back
Top