Thorley Headers

[Oatmeal]

I'm considering purchasing a Doug Thorley header for my '85 (22RE) p/u but, looking on their website they list eight different part numbers: http://www.dougthorleyheaders.com/ve...2=Show+Results so, I e-mailed them but, they haven't gotten back to me. Okay, before you think I'm totally inept, I know that the O and C suffixes stand for w/oxygen sensor and ceramic coated respectively but, no other info about the differences between them . As, there's a big difference in prices I would like to order the one applicable to my vehicle. So, those of you that have them, which one did you use? It's a California truck, by the way. Thanks in advance-------------Hans

[22RE_Railer]

I ordered my thorley header from summit. I just called and told them the year, and bang it showed up all shiny and ready to go!

[cherokeefreak92]

Thats why I like to got through summit because they know what they are doing.

[VasToyBoy]

#550Y in stock at summit....

And just IMO if you're considering the ceramic coated one, ya might consider getting the LCEngineering header instead...

[Oatmeal]

Originally Posted by VasToyBoy

#550Y in stock at summit....

And just IMO if you're considering the ceramic coated one, ya might consider getting the LCEngineering header instead...

Thanks, that's what I was looking for. And the Ceramic coated or LC Eng. headers are a little too pricey for me I know Northwest has a questionable reputation but, they sure do make a top notch header: http://northwestoffroad.com/parts/20-22header.html too bad they're not California smog legal----------Hans

[neilan]

i live in bellingham washington where northwest offroad is located and have never trusted there sutff. I have met the guy and he is not the best to work with and his store and bussiness has only gone downhill. He no longer has a store and is located mostly in his garage. just remeber nwor =no warrenties or returns. Go with the thorley from summit

[matter_daddy]

In California......get the Downey header......IMO

[steveh]

Search would have yielded this:

http://www.pirate4x4.com/forum/searc...earchid=943890

And my fav:
http://www.pirate4x4.com/forum/showthread.php?t=444240

[Booger Weldz]

what do these things go for? $$$?? imine is like 10 years old and though totally holding up like a champ, its getting ugly with cacked/burned on clay and mud from the local ohv park...

[bkubisht]

Be very aware of which style of air injection you have. One type has brackets that mount a pipe off of the head, and another type is held on directly with the exhaust manifold studs. I went through this a few years ago, bought the wrong one, and had to drill these holes through their VERY hard and thick flange. I'm referring to the holes on the THY-550Y that are missing in the THY-542Y, and the altogether different (off-head-pipe-mount) 542Y-SO.

And contrary to their note that the THY-542Y-O doesn't fit with a manual transmission, it fit just fine on my '87 with G52.

Basically figure out whatever smog device provisions you need by looking at your exhaust manifold, and then call them to be sure you buy something compatible. Or post a pic of your setup and I could probably advise better.

[Oatmeal]

Originally Posted by bkubisht

Be very aware of which style of air injection you have. One type has brackets that mount a pipe off of the head, and another type is held on directly with the exhaust manifold studs. I went through this a few years ago, bought the wrong one, and had to drill these holes through their VERY hard and thick flange. I'm referring to the holes on the THY-550Y that are missing in the THY-542Y, and the altogether different (off-head-pipe-mount) 542Y-SO.

And contrary to their note that the THY-542Y-O doesn't fit with a manual transmission, it fit just fine on my '87 with G52.

Basically figure out whatever smog device provisions you need by looking at your exhaust manifold, and then call them to be sure you buy something compatible. Or post a pic of your setup and I could probably advise better.

My '85 is a 22RE and has no air injection----------Hans

[AddictedOffroad]

Originally Posted by bkubisht

Be very aware of which style of air injection you have. One type has brackets that mount a pipe off of the head, and another type is held on directly with the exhaust manifold studs. I went through this a few years ago, bought the wrong one, and had to drill these holes through their VERY hard and thick flange. I'm referring to the holes on the THY-550Y that are missing in the THY-542Y, and the altogether different (off-head-pipe-mount) 542Y-SO.

And contrary to their note that the THY-542Y-O doesn't fit with a manual transmission, it fit just fine on my '87 with G52.

Basically figure out whatever smog device provisions you need by looking at your exhaust manifold, and then call them to be sure you buy something compatible. Or post a pic of your setup and I could probably advise better.

Uh, I have a 542Y-O on my 88' with a W56 and it fits fine............

Mine had the air induction too and I just welded a cap over the one port left open.

[Bansheestu]

I have the 555-y on my 89 4runner. It has the o2 down below on the connector pipe.

[surlynkid]

i just went thru this and got the wrong one from summit. where is your o2 sensor? is it up by the block toward the radiator, or is it down under the drivers's legs? teh first location is 550y. the second is 555y. i think the first is carbed and the second is EFI. mine was an 88 EFI and needed the 555y. both have air induction. if you go to thorley's site, you can click on the link to get big pics of each header.

[VasToyBoy]

Originally Posted by matter_daddy

In California......get the Downey header......IMO

Is anyone running the Downey header? Looks like a pretty nice piece. just never heard of anyone that has run one for any period...


A side note about the whole 02 sensor thing on thorley headers: My 86 had the sensor up in the manifold located so that it sampled off of all four cylinders, the thorley header only has it sampling of of one cylinder, which at least in my case, required moving the sensor downstream onto the collector in order for it to work correctly.

[slightdrift]

what downpipes are you doug thorley guys using? In the picture there are two short pipes with flanges on one side, what are these for?

[4in100]

Probably for connection to catalytic converter/muffler

[EarlKann]

Originally Posted by slightdrift

what downpipes are you doug thorley guys using? In the picture there are two short pipes with flanges on one side, what are these for?

One is a flanged extension to bolt on to the header, the other is to bolt on to the Cat. They slip together so presumably you can install the header to the cat in the stock position without having to go to a muffler shop to get it welded.

I have the Thorley and am very pleased with it.

[slightdrift]

so basically your saying the two pieces go together to make a downpipe?

[EarlKann]

Originally Posted by slightdrift

so basically your saying the two pieces go together to make a downpipe?

I wouldn't call it a downpipe but that might just be a terminology thing. They go together and fit between the header and the cat. The non flanged ends slip inside each other and you can put a clamp on them.

[4in100]

Are you running a RET?

[CanTheWhales]

Originally Posted by steveh

Search would have yielded this:

http://www.pirate4x4.com/forum/searc...earchid=943890

And my fav:
http://www.pirate4x4.com/forum/showthread.php?t=444240

did you ever get a hold of that spec sheet or switch back your headers...?

[steveh]

Originally Posted by CanTheWhales

did you ever get a hold of that spec sheet or switch back your headers...?

Nope, and no. I took the truck to Adco Driveline and Muffler of Shingle Springs and Ken there made the connector pipe.

http://www.pirate4x4.com/forum/showt...ight=o2+sensor

Totally happy with the header.

Relocated the O2, and upgraded to a heated one due to the relocation downstream.

http://www.pirate4x4.com/forum/showt...ight=o2+sensor

[Brian Ellinger]

Originally Posted by VasToyBoy

Is anyone running the Downey header? Looks like a pretty nice piece. just never heard of anyone that has run one for any period...

I havent seen one on a rig longer than 6 months without cracks, especially at the o2.

We've got a thorley probably ~12 years old now. Its been hit with rocks, reworked for clearance/angle with a torch (shove in a buggy) and still doing great.

[Bansheestu]

I am running the 555-y header on my 89 4runner. I called Summit and they didn't have a clue. I had to talk to thorley directly and send them pictures. Good luck getting ahold of Thorley, took me 3 months.