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doug thorley

S

SUA SPONTE

NAXJA Forum User
Location
Pacific N.W.
will a thorley header work in my 87 with 5spd tranny?
what will I have to modify? The thorley is the only head i can find with a life time warrenty but it only listed 91- 99 production years. Thanks for all the replies.
 
You will have to either get rid of the ERG, or get a exhaust shop to modify the header for it.

Im in the middle of trying to get a hold of Thorley to see if they would be willing to put an EGR bung on the header, but have not heard back via email. Im going to be calling later today.
Also look into Borla, but I have heard they discontinued the headers for XJS. :sure:
 
i just spoke to a guy at thorley....he said the amc inline 6 in my 87 is different(in regards to the exaust manifold) than the 91- 99 xj- so i have heard it will work and i have heard it wont. Any more input? Any one put a thorley on a AMC without any problems?
 
SUA SPONTE said:
i just spoke to a guy at thorley....he said the amc inline 6 in my 87 is different(in regards to the exaust manifold) than the 91- 99 xj- so i have heard it will work and i have heard it wont. Any more input? Any one put a thorley on a AMC without any problems?
Click to expand...
Alright, i just got off the phone with Nick from Thorley. From what he told me, I can just weld my own EGR bung thing on myself. The coating that they put on the header I can grind off and weld. He didnt really give me any good info about voiding any warrentee, but if anything happened to anything other then the spot of where I moddified it, there shouldnt be a problem with anything.
Im going to be getting a Thorley I think. Ill let you know where I can get the best price.
 
ok i did some digging around and also spoke to a guy out of AZ. his name is also Nick and Nick over at thorley is a vender of his. Well
1. The ports will not match up with an amc engine and the newer thorley header
2.I forgert his name put he designed the headers for mopar that are now out of production. If we can get a group buy of 20 he still has all the templates and stuff. This is a true long tube header. The reason its more expensive is because it has as much material as 8 cylinder headers. Any way Im not holding my breath waiting for 20 people to get on board with this. I have to cancel my order with thorley before i get charged shipping and Im pretty amazed that cheap ass pace setter is my only option other than the dual outlet cliffords.
 
hmm let em check again 563 doesn't sound right cause the price I found was cheaper then RR.

found the place on google, forgot to bookmark it.
 
Where they thinking of the 4.2? Tha might have different ports then the 4.0 but I thought the 4.0's were all pretty close to the same. And wasn't the 4.2 the AMC motor and the 4.0 Chyrsler at least for who had thier named stamped on what.
 
I have the Mike Leach header from Nick, and it is sweet. I don't know if it also fits any of the wranglers, but if it does, you might have a shot at hitting the 20 mark by checking out interest over at jeepforum and JU.
 
Weasel said:
Where they thinking of the 4.2? Tha might have different ports then the 4.0 but I thought the 4.0's were all pretty close to the same. And wasn't the 4.2 the AMC motor and the 4.0 Chyrsler at least for who had thier named stamped on what.
Click to expand...
Yeah, Im fairly sure all the exhaust for the 4.0 is the same. Im going with that assumption and getting the Thorley header.

Weasel, you ever find that place thats cheaper then rocky road?
 
Ok guys lets lay this myth to rest... 87~90 4.0 is the Renix injection ( egr ) and the exhaust ports are lower on the head. 91~2001 4.0 HO. has the exhaust ports higher in the head casting. The HO header will not fit PROPERLY on the renix head, Why? The layout is the same for the 4.0's but the port height spacing is different from the early to late design. I had both cyl heads side by side in early dec, while changing the head gasket on my heep.. I was debaiting using the HO head for a while untill I test fit the mainfolds from the renix. I am telling you it wont work Properly. They will bolt on and fit, but you will have leaks, both exhaust and intake.. I am not trying to rain on anyones parade, just don't want to see people throwing money away on what might or might not work... Oh I would seriously talk to Doug about making the headers for the Renix.. Nothing against Mike Leach...
 
Well thank you! And I'm serious. I have post this exact subject, once just a few weeks ago and once quite awhile ago and kept getting the same responce, that they would fit although never heard from someone that did it.

Whats the deal with Doug vs. Mike Leach? Suppostly the Thorly ones are the same ones MIke used to make? Or not?
 
Weasel said:
Whats the deal with Doug vs. Mike Leach? Suppostly the Thorly ones are the same ones MIke used to make? Or not?
Click to expand...

Its the other way around... Mike Leach purchased the Doug Thorley name and rights a few years back, and Doug is suposedly making headers again under a different name... Go with the Original...
 
Ok, was Mike making the Mopar headers at the same time?

I was talking to Clifford Performance and he said that their header fit all of the 4.0's and the different ports didn't matter. They have used them on both and they worked fine. He did say on the high ports some material might have to be taken off the intake.
 
Clean-RC said:
Ok guys lets lay this myth to rest... 87~90 4.0 is the Renix injection ( egr ) and the exhaust ports are lower on the head. 91~2001 4.0 HO. has the exhaust ports higher in the head casting. The HO header will not fit PROPERLY on the renix head, Why? The layout is the same for the 4.0's but the port height spacing is different from the early to late design. I had both cyl heads side by side in early dec, while changing the head gasket on my heep.. I was debaiting using the HO head for a while untill I test fit the mainfolds from the renix. I am telling you it wont work Properly. They will bolt on and fit, but you will have leaks, both exhaust and intake.. I am not trying to rain on anyones parade, just don't want to see people throwing money away on what might or might not work... Oh I would seriously talk to Doug about making the headers for the Renix.. Nothing against Mike Leach...
Click to expand...
I beg to differ on this. They did not move the exhaust ports, they moved the intake ports. The HO header will fit fine to the head however you need a new downpipe and you will have to figure out the EGR tube if you want to retain the EGR system. I have held the gaskets side by side to compare and I to this day am using an HO exhaust manifold on my Renix head and I have NO leaks whatsoever. It will fit fine unless it comes out at an angle like the Banks header does in which case the Renix intake manifold will not clear it.
 
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