12 replies to this topic

[Redbaron6969uk]

I appreciate its not the way everyone wants to go but I intend to go back to standard HF4 carb, filterbox and manifolds. 

Can anyone advise, is the Cast iron manifold 12G 787 different for the 1275 engine as opposed the same manifold fitted on the 998?

 

Cheers

 

[andyapanel]

I don't know, but why not have a look at the Somerfords and Minispares sites where they identify parts?

[Tommyboy12]

12G787 was fitted on some 1275s across the BL range and will serve as a replacement for a 1275GT.

[Redbaron6969uk]

Yes Andy i tried to identify it via the minispares website etc. but on this one it caused me even more confusion to be honest.

 

Looking at it, it looks like the HS4 set up i.e. 12G787 manifold, 1.5 inch carb and filter housing were standard across the range in 1979, including the 1275gt and 998 models, however the exhausts were different so wondering if the manifolds were in anyway modified as std for the GT to match ports and exhaust diameter.

 

or if i have it totally wrong and it was something completely different. 

 

I'm a little confused on this one and would love some confirmation if anyone knows.  

Edited by Redbaron6969uk, 23 September 2021 - 04:17 PM.

[fordson]

What year car have you got? I’ve got an early 70gt it’s got a 12G 1540 but I’m not sure if it’s original

[Redbaron6969uk]

What year car have you got? I’ve got an early 70gt it’s got a 12G 1540 but I’m not sure if it’s original

1979

[GT Jimmy]

I'm pretty certain I've got the original one off my 80 GT in the loft, I'll have a look tomorrow and get photos of any casting numbers

[GT Jimmy]

My original inlet is a 12g787, if you're close by you can have it. Also got the hs4, air box, original dizzy and other bits I might be persuaded to part with

[andyapanel]

I have just checked my spare parts and its the manifold I removed from my RSP.

There is a Metro one that looks similar and I have a 1275 Allegro one, but I think it is twin downpipes.

They are real so and so s to clamp the manifold to the exhaust.  Glad I removed it.

[72gt]

I’ve a 12G1540 fitted on my 72’ has the servo non return valve threaded into the top of the manifold.

[Spider]

The Manifolds fitted on the (post 1975) 998's and the 1275's we had here were different. These were fully built up units (including Manifold and HS4 Carb), ex-UK. These 1275 engines were the same as fitted to the 1275GT.

 

The difference with them was the Exhaust. The 998 Manifolds were made to take a 1-1/4" Pipe, where as the 1275's took a 1-1/2" Pipe. I have some of these manifolds, I don't know what the numbers on them are off hand, but I'll try and remember to look and snap off some photos.

[Spider]

There was in fact 2 manifolds fitted to the 1275GT, the 12G2292 was the earlier one, which if memory serves, that was for the 1-1/2" Exhaust Pipe and would only accept a HS4. The later one was a 12G3729, which I believe was the same, only it had the 'square' carb mounting that would accept either a HS4 or a HS6. Sadly, while these are Part Numbers, the Numbers that are cast in to the Manifold is different.

 

 

This later one has the number 12G3538 cast in to it

 

 

These did have slightly bigger exhaust ports than the small bore manifolds;-

 

 

The 1275GT Manifold on the lower.

 

 

 

My original inlet is a 12g787, if you're close by you can have it. Also got the hs4, air box, original dizzy and other bits I might be persuaded to part with

 

I doubt that's an original type. That was for the 1-1/4" Exhaust Pipe.

[GT Jimmy]

There was in fact 2 manifolds fitted to the 1275GT, the 12G2292 was the earlier one, which if memory serves, that was for the 1-1/2" Exhaust Pipe and would only accept a HS4. The later one was a 12G3729, which I believe was the same, only it had the 'square' carb mounting that would accept either a HS4 or a HS6. Sadly, while these are Part Numbers, the Numbers that are cast in to the Manifold is different.



This later one has the number 12G3538 cast in to it



These did have slightly bigger exhaust ports than the small bore manifolds;-



The 1275GT Manifold on the lower.


 

My original inlet is a 12g787, if you're close by you can have it. Also got the hs4, air box, original dizzy and other bits I might be persuaded to part with

I doubt that's an original type. That was for the 1-1/4" Exhaust Pipe.

 

It was taken off an unmolested car that was only 10 years old when parked up and forgotten about, I presumed it was original. It'll never go back on the car. I must admit when we stripped the car I thought it was a little bit "skinny"

Edited by Spider, 26 September 2021 - 12:47 AM.