27 replies to this topic

[wot179]

I am wondering about the variations in cast iron exhaust manifolds between

HD/HR X2, GTR and 6 cylinder GTS.

Pics of bare manifolds would be great.

[lx308]

Hi Wot, this shows the X2 headers.

[wot179]

Thanks Tony.

Are there only two types?

The text on that photo is a little confusing...

[Bazza]

Hi

 

I posted the pic of the headers and the text a number of years ago. I tried to add as much info to the pic as I could without confusing the issue.

 

There are 2 types of header sets. Basically one for X2s (with some exceptions) the other for the LC GTRs, both model XU-1s and 186s.

 

There are 3 versions of the front section; 1. no casting for the auto choke pipe, 2. casting for the auto choke pipe but not drilled, and 3. casting for the auto choke and drilled to accommodate riser pipe.

 

All 3 versions of the front section will 'fit' either the X2 or the LC GTR, XU-1s or 186s. The plain (no casting) was originally fitted to the X2 but the drilled auto choke version is needed for the LC GTR and 186s.

 

There are 2 versions of the rear section; 1. the flange points more downward, 2. the flange is longer and points more rearward as in the above picture.

 

Both versions will 'fit' but if version 1 is used on an LC GTR, either model XU1 or a 186s, then a custom made engine pipe will be required.

 

Typically LC GTRs, LC XU-1s and LJ XU-1s are fitted with front version type 3, and rear version type 2.

 

I can supply the part numbers but that would confuse matters even more.

 

Cheers

 

Bazza

[S pack]

Thanks Tony.

Are there only two types?

The text on that photo is a little confusing...

Yeah, only two types of castings for the headers. The rear manifold on the X2's has a different outlet angle and the front manifold doesn't have the auto choke heat tube.

[Dr Terry]

Just to clear up some confusion, the rear section you have labelled 'X2' will only fit the HD 179 X2. The HR X2 rear section is the same as the 186S, GTR & GTR XU1. The HD had 2 separate engine pipes all the way to the front muffler whereas all of the others had a Y-pipe which will not fit up to the HD headers.

 

If you're concerned about function & not about originality all 3 front types are interchangeable unless you need an auto choke in which case you will need the 'drilled' one.

 

The rear one is easier to sort. One fits HD only & the other fits all of the others.

 

Dr Terry

[wot179]

Thank you gents.

Anyone got an undrilled set they would like to sell before I hit ebay?

They are for my HT.

Edited by wot179, 26 July 2013 - 03:53 PM.

[lx308]

This fella had a set for sale I believe.

http://www.gmh-toran...r/3158-aggetts/

[Dave6179]

And again... Mr Brock reckons a divider in the rectangular ports adds 10hp.

[S pack]

And if you wanted to make serious horsepower you'd throw the cast iron manifolds and get extractors or tubular headers.

[TerrA LX]

I want to know how he is going to bolt these to the SBC?

[S pack]

I want to know how he is going to bolt these to the SBC?

Easy, cut a couple of cylinders off and make it a V6.

[biga064]

Hi yet to find a set of off the shelf extractors that will out torque and out power my modified power ported cast iron headers !!!!

And if you wanted to make serious horsepower you'd throw the cast iron manifolds and get extractors or tubular headers.

[Dave6179]

Not to mention being a lot quieter too. And less to burn yer hands on!

[S pack]

Not to mention being a lot quieter too. And less to burn yer hands on!

Cast iron manifolds quieter than extractors you say.

They probably are, but I reckon the db rating of an exhaust system has more to do with the particular mufflers, resonators etc used.

 

Someone more knowledgeable on exhaust systems may be able to elaborate.

[TerrA LX]

Cast iron manifolds quieter than extractors you say.

They probably are, but I reckon the db rating of an exhaust system has more to do with the particular mufflers, resonators etc used.

 

Someone more knowledgeable on exhaust systems may be able to elaborate.

Engine bay noise.

[micklx]

_{Fascinating. I've had a few sets of these pass through my hands over the years, and always assumed they were all the same. This website continues to be a wealth of information...}

[S pack]

Engine bay noise.

Yeah, I get what he means now. Thanks Terry.

 

Cheers

Dave.

[wot179]

The reason Im after a set is that the ol 161 in The Goon is getting a little tired and

Ive got this virgin 186 laying about and an old yella terra head gathering dust...

plus a new set of pistons that are just laying about and a webber on a long runner Lynx manifold...

So if I grab a new mild cam it might just be time to give the ol girl a bit of a birthday.

Nothing rocket sled, just a bit of a crackler with a few more herbs.

I don't want it eating tons of juice and I want to keep it reliable, but a bit more scoot would be nice.

[wot179]

Thanks for the offer but your buddy wants too much.