chappers1.3
19-06-07, 12:26 PM
Been reading alot about this on various sites so decided to try it myself. I got a set of carbs, with airbox and fuel pump all off an R1 for 130quid which i didnt think was too bad.. decided that Bogg Brothers can stick their 190quid+vat manifold and have opted to make my own one......... so started....
Engine is a 2ltr 8v with a 1.8 big valve head, i remembered i had the original manifold (1.8) to hand so i destroyed it with an angle grinder.... ended up with quite a nice face plate that is ready to bolt onto the head with all holes in correct place so that has saved me time making templates etc. all i need now is 4 tubes welding onto the face plate at the correct angles to suit the carbs. ports on manifold are 90 - 90 - 90mm centre to centre where as carbs are spaced 75 - 85 -75. this means middle 2 will be near enuf straight and outside 2 will have to be angled in by about 20mm each. ideally i would like carbs about 90mm away from head - dont knwo where i read it but thats what i am going to try n make them to.
Now my questions?
The ports on my inlet are 37mm.... R1 carbs have a 40mm port. so i will have to make the tubes with a slight cone if i want to match them up using the R1 adaptors? this will give the manifold a slight venturi effect speeding up Airflow into the engine... can anybody think of a problem with this?
or my 2nd idea was.......
get some pipe as close to 37mm I/D cut to length (will be abit shorter than 1st idea by maybe 40mm or so) and and just use some silicon hose to connect the manifold to the carbs. i know that this 2nd idea could possibly reduce flow - again anybody any ideas???
also - brake servo vacuum pipe....... of course i will need one of these adding the the manifold, i am quite stuck about how to add this, and where to put it.. thinking that i can just take a feed off one of the manifold tubes??? is this how its done on your normal weber manifold for carbs/throttleboddies?
thanks.....
Engine is a 2ltr 8v with a 1.8 big valve head, i remembered i had the original manifold (1.8) to hand so i destroyed it with an angle grinder.... ended up with quite a nice face plate that is ready to bolt onto the head with all holes in correct place so that has saved me time making templates etc. all i need now is 4 tubes welding onto the face plate at the correct angles to suit the carbs. ports on manifold are 90 - 90 - 90mm centre to centre where as carbs are spaced 75 - 85 -75. this means middle 2 will be near enuf straight and outside 2 will have to be angled in by about 20mm each. ideally i would like carbs about 90mm away from head - dont knwo where i read it but thats what i am going to try n make them to.
Now my questions?
The ports on my inlet are 37mm.... R1 carbs have a 40mm port. so i will have to make the tubes with a slight cone if i want to match them up using the R1 adaptors? this will give the manifold a slight venturi effect speeding up Airflow into the engine... can anybody think of a problem with this?
or my 2nd idea was.......
get some pipe as close to 37mm I/D cut to length (will be abit shorter than 1st idea by maybe 40mm or so) and and just use some silicon hose to connect the manifold to the carbs. i know that this 2nd idea could possibly reduce flow - again anybody any ideas???
also - brake servo vacuum pipe....... of course i will need one of these adding the the manifold, i am quite stuck about how to add this, and where to put it.. thinking that i can just take a feed off one of the manifold tubes??? is this how its done on your normal weber manifold for carbs/throttleboddies?
thanks.....