Couple of Questions

[Duccout]

Hi,

What is the difference between wide-case and narrow-case heads? I think that I remember that the narrow-case has a different squish angle? I have tried a search here but nothing comes up.

Secondly, those using Amal carbs, where do you get your rubber spacers (between carb and inlet flange) from? Do you use those from a specific British bike?

Thank you,

Colin

[blethermaskite]

Colin, I don't think there is any difference (could be wrong) I think the squish difference you suggest is between 250 and 350 heads but I have never actually measured it, pretty sure Nigel referred to this in some post on here somewhere. I never use those rubber inlet spacers....in my opinion they are just an air leak waiting to happen, Cheers George

[George]

I believe Jesus Guzman stocks rubber inlet spacers

[blethermaskite]

Colin, sorry I misread in your post, what is the 'rubber spacer' between the Amal carb and the inlet flange? Assuming you mean flange type Amal's? I thought you meant the rubber spacer between the std Dellorto carb inlet spigot and the head (which I won't use) With Amal's I use either an alloy inlet spacer or my own preference is a tufnol spacer (thermal barrier). Amal 'flange' carbs...monobloc's concentric's GP's TT's are all subject to greater or lesser degrees of having easily distorted flange's and a rubber inlet spacer will just make the situation worse.
Not sure if that's the answer you are looking for?
Cheers, George

[Duccout]

Hi Both Georges,

Thank you. The reason I ask about the rubber manifold spacer between Amal carbs and the inlet flange is that my 250 carb is 27mm and the only spacer that I could find of 27mm was the one that Jesus Guzman sells, but it is very thick and squishy and I can flex the carb back and forth, indicating that it could be leaking air. I would prefer a tufnol type but I could not find any in 27mm.

Cheers,

Colin

[themoudie]

Aye Colin,

Same as George, if you are refering to the AMAL flange carbs and not the MKII Concentric?

Always used a Tufnol spacer between the carb and the cylinder head. Link to the Tufnol website below, if you want to know more? Followed by a link to the "Classic Bike Shop" who supply Tufnol spacers, with a 32mm bore. I am sure there are other alternative suppliers.

Tufnol_website or Direct Plastics Tufnol web pages Direct_Plastics_Tufnol_info

As with most engineering materials these days, you pay for the correct grade of material, in this case Tufnol "Whale", or "10G/40".

Classic_Bike_Shop_Tufnol_AMAL carb_spacer_32mm_bore

This link below, to the AMAL website, with regard to tightening the flanged carb to the cylinder head should be heeded!

Installing-AMAL-carburetters

Hope this helps answer yours and others questions.

Good health, Bill

[George]

Hi Colin, I bought a sheet of 8mm thick tufnol and made a heat shield spacer. I have more than I will ever use and can cut a piece off if you want to make one. Will post or if you want to put some miles on the Enfield pop over to Canvey.

[Duccout]

Hi George,

That is really kind of you. PM sent.


Cheers,

Colin

[Eldert]

Hi Colin

the 350 cc narrowcase Sebring has a diff angle squish band and i think some of the very late Mototrans 350 widecases to

40 versus 45 degree angle is my memory serves me correct

Eldert

[Duccout]

Hi Eldert,

Thank you.


Cheers,

Colin