Identifying Worked On Head

[brian j 32]

Hi,

 

I bought the following head on ebay as a "Longman big valve head" with 43.5mm inlets and 35.5mm exhausts.

 

It was missing a tappet, shim, valve spring, and retainer and collets.

 

It very clearly has been ported with 3 angle seats, but the rest of the description is wrong so I'm wondering if anyone can help me ID who may have done the work so I can get some specs on it...

 

pictures are as follows:

 

http://i424.photobucket.com/albums/pp321/brianphotobucket/IMG_0361.jpg

 

http://i424.photobucket.com/albums/pp321/brianphotobucket/IMG_0364.jpg

 

http://i424.photobucket.com/albums/pp321/brianphotobucket/IMG_0366.jpg

 

http://i424.photobucket.com/albums/pp321/brianphotobucket/IMG_0370.jpg

 

http://i424.photobucket.com/albums/pp321/brianphotobucket/IMG_0369.jpg

 

http://i424.photobucket.com/albums/pp321/brianphotobucket/IMG_0372.jpg

 

I got a good price, so am not too bothered if it's not a Longmans head, but it does seem to have had some time spent on it so would like to ID who did the work and what has been done.

 

Also if a standard set of valve collets will fit or not.

 

Thanks

[welshpug 1,661]

any numbers stamped on it?

 

edit, yeah

 

I would have said give longmans a ring with that number, but I don't think you'll get hold of them that easily any more.

Edited March 4, 2012 by welshpug

[daneldridge23 15]

are the ones in the first picture, manufactures?

[brian j 32]

The ID in the first pic is not from Pug, it is the ID stamp from whoever modded it.

 

Who they are I don't know.

 

I have asked Brett Sims if it is a Longman head and am waiting to hear back, but I think not because aparently their ID stamp is a 4 digit and a separate 3 digit, which my head is missing. (BTW, he is a thoroughly helpful guy!)

[daneldridge23 15]

i have a hi flow head in the garage ill go see what it has on it mate

[daneldridge23 15]

mine has 2437 but has hfh on it, does the person you bought it if know?

[Baz 421]

It does appear to be a Longman number, but you're right there's usually three more below it. Brett should be able to tell you more.

 

It looks to me as if the ports have been played with a bit more though.

Edited March 4, 2012 by Baz

[brian j 32]

Thanks all for your input. According to Brett Sims it is a Longman head!

 

Now if the combustion chamber volume is 31cc (which it is...) what will my compression ratio be on

A standard 1.9 bottom end?

I can't work it out using an on-line calculator because I don't know how far down the bore the piston sits at TDC

 

 

(null)

[welshpug 1,661]

that'd be quite easy, work backwards

 

http://www.pumaracing.co.uk/CAPACITY.htm

 

standard gasket is 1.6 mm x 84mm Dia iirc, (8.4 x 8.4 x 3.14159 / 2) = 55.417 cm2 x 1.4mm = 8.86cc

 

standard compression ratio is 9.6-1, calculating back (476.25cc/8.6)=55.37cc

 

standard combustion chamber volume is 34cc.

 

hence standard dish inc deck clearance if any is (55.37-34-8.86)=12.51cc

 

 

 

 

so, with your 31cc chamber and standard gasket (8.86cc) plus standard guess at the dish (12.51cc) you'd be looking at about 52.37cc combustion chamber vol, on a 1905cc you'd be at [(476.25+52.37) / 52.37]= 10.09-1 compression ratio .

[BlueBolt 156]

that'd be quite easy,

 

My goodness, when you put it like that I have no idea how I missed it...... :S lol

[petert 588]

Amd 10:1 is perfect to make the standard cam come alive.

[Baz 421]

Not enough though. Put 1.6 pistons in it and a larger cam and it'll really be a lively engine. A shame not to when you have a head like that!