hi people, noone seems to have a manifold for an afh for sale on here, and i dont have the time to make one.

so i was wondering, is it possible to cut down the standard afh manifold quite short, and use silicone hoses to join it to bike carbs?

oobviously id have to block the injector holes

this been done before? anyone see a reason why it wouldnt work?

cheers. eric

Edited 8 September, 201115 yr by erixtar1992

There was a thread recently with some one asking why their carbed afh was running like a sack of shit. He mentioned he had used the afh mani and silicone hoses which was leaking vacuum badly, I've seen another post since then from him saying his engine is now dead.

It seems like the afh mani isn't suitable for this job due to its shape and design giving issues when trying to get it to seal well. If it doesn't seal properly not only will it run rough but it'll also run lean which could lead to melt down of major engine components

yeah thats fair enough, i was planning on cuttin it down before the bend and then probably filing the outside of it smooth for that exact reason so it seals better. so surely if i do it right it could work i guess?

If you can get it to seal properly then maybe it could work well enough, whether it will flow very well I have no idea, but the sealing seemed to be the major issue the user on here was having

If you can get it to seal properly then maybe it could work well enough, whether it will flow very well I have no idea, but the sealing seemed to be the major issue the user on here was having

alright mate cheers. any idea what section his thread is in? wouldnt mind taking a look

ahh just found it. seems that he literally just chopped the manifold in half and wacked his carbs straight on. i was planning on filing it smooth, so maybe itl work. only one way to find out i suppose! haha

manifold is going well! hoses seemed to seal well enough for it to be used. need to blank off the injector holes though. any ideas?

drill and tap and put blanking caps in? leave injectors in?

drill and tap and put blanking caps in? leave injectors in?

ooo leaving injectors in sounds like a plan for now! good man!

You could always use the injectors for nos later!

Why not just tap them and fill the hole with a stubby bolt?

You could always use the injectors for nos later!

Why not just tap them and fill the hole with a stubby bolt?

yeah boi! haha fast n furious ftw!

looks like thats what I'm gonna have to do! just got to find the right tap! will probably use injectors as a temp fix :)

why not just do it properly in the first place

why not just do it properly in the first place

because i dont have time, its only gonna be temporary probably

why not just do it properly in the first place

This.

If you're going to run the original manifold, atleast block off the holes properly. A tap isn't too hard to come by, and use a stubby bolt.

See tbh though, I'd just build your own.. Harris did his pretty quickly IIRC with a file.. Looked good too..

If anyone decides to build a proper mani either:

with a drawing like that, i could have had my base plate made via an aquacutting machine for the price of 4 cans of stella.

i built one before for my 8v, did it on the milling machines at college, was good but a right pain! unfortunately I've finished the course now do no access to proper tools so id have to buy one. what sorta tap size do you think would be good?

aside from the injector holes however, this manifold isnt looking too bad tbh! plus i know itl deffinately fit the engine properly i guess. idk, ill see how it goes. cheers for the advice guys.

remove and injector, and measure the hole size, then people will recommend you a size

I'd just tap the hole that's already there?.. Just get a tap that's the same size as the hole, then the corresponding bolt..

mattway & loon27 (owned same car)

ran a cut down standard afh manifold and it ran 100% fine as far as I'm aware

obvs a proper manifold would be loads better though

mattway & loon27 (owned same car)

ran a cut down standard afh manifold and it ran 100% fine as far as I'm aware

obvs a proper manifold would be loads better though

Awesome stuff! Cheers!

progress so far:

even though its still a bit rough, and i haven't finished rounding it off, the rubbers sealed perfectly fine and fitted nicely! gonna smooth them off some more though.

can i mig weld over the injector holes? or am i being an idiot. I'm not clued up on welding just know how to do it. haha

Edited 3 September, 201115 yr by erixtar1992

you cant mig ally.

also, the injector holes may not be the ideal tapping size you see, unless they're say 6.75mm or 8.5mm, or 10.25mm etc

you cant mig ally.

also, the injector holes may not be the ideal tapping size you see, unless they're say 6.75mm or 8.5mm, or 10.25mm etc

ok mate thanks. ill work something out lol

you maybe able to, but not with steel mig lol.

I recon your engine is doomed, i think the flatter sides of the oval will leak whether you think they seal satisfactorily or not.

I did look into doing the same thing, and decided i couldn't pull it off.