Stage 1 with P76 4.4l exhaust?

[cjc_td5]

I have a Series III Stage 1 with a P76 4.4l motor which I am refitting the bulkhead and gearbox, so whilst I have it all apart, the exhaust is in need of some attention also.

http://www.aulro.com/afvb/attachment.php?attachmentid=111969&stc=1&d=1469862896

http://www.aulro.com/afvb/attachment.php?attachmentid=111970&stc=1&d=1469862896

Any idea what manifold and pipes it may have it at the moment?

I have read that the 3.9l v8 has what is considered to be a fairly efficient exhaust system and I happen to have a 3.9l v8 as a spare motor in the shed. Would the 3.9l exhaust manifolds bolt directly on to the 4.4l heads?

Now I understand that the P76 4.4l v8 has a longer stroke and therefore the heads are 40mm higher than a landrover v8. I presume this means that a standard land rover set of extractors will not fit? They may either foul on the chassis or the cross pipe will be modding as the heads are higher and further apart?

Would you suggest sticking with the cast manifolds (either existing or 3.9l) or going to a extractor setup?

I don't want a race car, I want torque for lazy driving, and of course a nice v8 burble....:D:D

Cheers,
Chris

[bee utey]

You have early Land Rover exhaust manifolds on this engine, they are a direct fit. The block is 20mm higher in the stroke direction not 40mm, the outwards movement is around 12mm. Extractors tend to be a tight fit, but sometimes you can just bolt them up and heave mightily on them to adjust the fit, or slightly shave the flanges. The dual outlet Disco manifolds will fit too, however the engine pipes may play havoc with the cross member. Later exhausts run under the cross member which is tubular instead of square. You may be able to fit the later cross member off the donor Disco, not sure on that one. Personally I wouldn't recommend extractors, they make access difficult for little torque gain.

[cjc_td5]

You have early Land Rover exhaust manifolds on this engine, they are a direct fit. The block is 20mm higher in the stroke direction not 40mm, the outwards movement is around 12mm. Extractors tend to be a tight fit, but sometimes you can just bolt them up and heave mightily on them to adjust the fit, or slightly shave the flanges. The dual outlet Disco manifolds will fit too, however the engine pipes may play havoc with the cross member. Later exhausts run under the cross member which is tubular instead of square. You may be able to fit the later cross member off the donor Disco, not sure on that one. Personally I wouldn't recommend extractors, they make access difficult for little torque gain.

Thanks bee utey, I was hoping you would chime in. Do you recon the 3.9l dual disco manifold offers a worthwhile improvement over changing from the stock manifold?

[jimr1]

I also have a 4.4 p36 motor fitted into my old 110 . These motors would pull Christ off his cross . I have extractors . They weren't cheep $ 700 plus fitted , I think I would try the 3.9 disco pipes if I ever went down that road again ! The other thing is they run very close to the clutch slave cylinder . I put an R380 in mine out of a Disco , that extra gear made so much difference . Good luck . Jim :)

[cjc_td5]

I am going down the 3.9l EFI v8 headers route with my stage 1. I have some cast iron manifolds but had to buy some down pipes. They came from a "bricks and mortor" Land Rover Specialist but when I got them home the 2-1 collectors have been manufactured without a collector adapter but just by crushing the pipes into the downstream pipe!

http://www.aulro.com/afvb/attachments/series-iii/114138d1474257639-meet-vincent-stage-1-v8-20160919_114737-m.jpg

I have asked the shop but they say they are all like that. How inefficient would this setup be really? I have to get a custom pipe made from the crossover pipe backwards, so would it be worth getting proper collectors welded in then?

Are the upstream pipes "tuned" to a particular length and so the collector cannot be welded in further up the pipes where they are still round?

I'm not chasing the last 2% for a race car, but I don't want to stifle the engine either....

Cheers,
Chris

[TimNZ]

Take them back, no way would I put those on a car I owned! I don't know how anyone could sell them with a straight face.

Cheers -

[bee utey]

I wouldn't stress over changing the primary pipe lengths, after all your engine doesn't even run the same bore and stroke as the 3.9. Any competent exhaust builder should be able to fit up some proper collectors, heck, I have even made my own collectors to replace some of the rubbish exhaust bodges I've seen over the years. You can even supply your own collectors to the exhaust fitter, just look on ebay for suitable ones. Example:

Exhaust Collector MILD Steel 2 Into 1 IN 47mm OUT 51mm | eBay (http://www.ebay.com.au/itm/EXHAUST-COLLECTOR-MILD-STEEL-2-INTO-1-IN-47MM-OUT-51MM-/272171140938?hash=item3f5eaa074a:g:ufEAAOSw8w1X3l7 0)

[Pedro_The_Swift]

How do any of those seal between the pipes?

and the longer secondaries the better,,

[350RRC]

...............

I don't want a race car, I want torque for lazy driving, and of course a nice v8 burble....:D:D

Cheers,
Chris

Hi, I've got a 2 door RRC with a tweaked 4.4.

Has headers and a 3" mandrel bent exhaust.

Has one of the best notes I've heard from a V8!

DL

[bee utey]

How do any of those seal between the pipes?

Welding them together internally before fitting the collector, usually. You can also build collectors similar to the ones pictured below, only instead of flattening the pipes you cut away the adjoining areas and weld them externally. All it takes is time and skill, which drives up the cost of manufacture and produces a premium product. As I said, any competent exhaust fitter.

[cjc_td5]

How do any of those seal between the pipes?

and the longer secondaries the better,,

And the longer the primary pipes pulls the peak torque down the rev band?

And is the "primary length" actually the first length inside the cast manifold before it goes 2-1, and the down pipe a "secondary" length??

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