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Discussion Starter #1
Decided to try and make my own inlet manifold for several reasons:
- save myself £190 by not buying a Bogg Brothers one & dont have to wait 12weeks lmao
- Its a good project
- Its custom
- I can port match the face plate to the head exactly, get it sat how i want, and have also tried to work out where my max torque will be, incorperating it into the runner design

The best bit....
total cost = £30 for some ally tube - rest is time

Started off by getting the old 18e inlet manifold and chopped the runners off leaving me with a face plate. then took it to my ladyfriends house and machined it flat (her father handily has a lathe and milling machine). I then bolted it to the head and was gobsmacked how much overlap the standard manifold had, it wasnt round and was a good 3-4mm off centre to the head port, so i got a angry drill thingi and took the excess metal away from it - its now nice n smooth, flowing into the head.
also i got to keep the alternator bracket mount - BONUS!!

here is the face plate:
http://i306.photobucket.com/albums/nn254/chaps1985/DSCN1042.jpg?t=1210806407

I then got 1m off Aluminium tubing from local metal merchants. it took me a while to find the right size tubing to suit the Carb rubbers (i am using the standard R1 rubbers) these have outside diameter of 45mm, and internal of 40mm.... the only pipe i could find was 45mm OD and 37mm ID.. i think it was SWG10 thickness.

I cut a lenght of 60mm off and got it set up in the lathe and got a clean face on it (i cant hack saw straight to save my life). once this was done i set to about opening the Internal diameter to 40mm from 37... i chamfered the inside out over 40mm, i think i set the lathe at 2degrees. it turned out pretty well, so next job was to put a little Lip on the edge so it would locate with the carb rubbers... they have a groove on them to keep them tight. this is what i ended up with...



to make 4 of them took me about 2hrs but i was very happy with them, you can hardly feel a step when u run your finger from the manifold, accross the rubber, and into the carb body.

Next was to make myself a Jig... well, to be fair i must give my mate some credit - he made it 4 me ... to get the carbs and manifold to fit and sit right in the engine bay i wanted to angle them upwards, so i set the jig at 30degrees sloping up towards the bonnet. i can move the carbs up and down, but they are fixed at 30degrees..

here is the carbs with the 4 x 50mm tubes sat in the jig... its a pain in the arse to get it all set up square with the face plate but once u have it right u can lock it up tight so (hopefully) i wont have to set it all up again




as u can see from the photo the carb spacing is narrower than the manifold ports

I then chopped some more pipe up, i wanted the manifold to be about 6" long, so made the middle tubes at 4" abouts, i cut them at 30degrees to save filing, but have had to file n mess about with them quite abit to line up....

Here is where i am at now.... I got the 2 central Runners nearly right.... not perfect but pretty close..



Here is another view, you can see the 30degree angle better on this 1.


i am hopefully going to the the other 2 runners done in the next few days, i'll post some more pics then.
 

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Excellent stuff fella. I like it alot and shall watch this thread with great interest.

Was only tonight a freind and I where commenting on how shocking the price is for some inlet manifolds for Jenveys these days..

You may make yourself a bit of beer money if these work out okay:nod:
 

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Discussion Starter #7
cheers 4 the comments guys, hope its gonna work out well and give some good gains.
with the head, these carbs and manifold and the early 18e cam i am hoping to get about 160-165bhp from the engine, with max torque about 5400rpm.....i'd be happy with that anyway!

i think altogether its prob taken about 6 or 7hrs work so far done over a couple of weeks.
as i say hardest part was setting it all up square so the carbs dont sit on an angle when they are bolted to the engine. as u take metal off the pipes, the carbs need to drop down abit, and then the face plate needs to move abit also. think its nearly there tho, so i am going to mark round it all so if i have to move it i can set it up quickly again.

thanks 4 the offer on the dizzy set up spuds_own, i got one already but its off the 1.6 so i think the advance curve may be problematic? i sure i read the 1.8 one is better?

Do you have any pics of your manifold?
 

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It's great being able to have access to machine your own stuff for your car, saves a lot of time and money. Good workmanship there too looks like a good little project.
 

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Discussion Starter #10
Hi again,

thanks for all the comments on the manifold, it was really fun making it and felt like i was contributing to the cars performance and actually Engineering something to save me cash. As a few of you are aware i have changed plans and am breaking the nova now, I am not going to be needing this stuff.

IF any1 wants to buy the 18e head I have for sale, I will be including all the work i have done for the manifold and the Jig to hold them for it to be finished. After all the work i have put in i cant throw it away. So... To jsut give a quick update from the last section i wrote, I've nearly got the outer 2 runners to match, they do need abit more filing but are quite close now, i should expect a couple of hours tweeking will get it fitting really nice.

Save yourselves 190quid, and finish my project, put some more pics in this guide for every1 else too see lol......... head is to suit any big block 8v engine!!!!

Its advertised in the For Sale thread - R1 carbs, forged pistons shell etc..

Thanks 4 your interest & comments.
Chaps
 

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good work, I like these mig, build yourself tuning parts threads.
It wasnt a proper MIG project till the "breaking for spares" post lmao
 

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Discussion Starter #13
A real shame you arent finishing this. It was a good read up until now.

Craig,

as you have said this, i think i will keep my head and finish the project even tho i am selling the carbs.

will get some pics when i do some more work... long live the nova!!! lol

chaps
 

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nice idea i am also making my own inlet for my gsxr throttle bodies.iv also got a mk1 astra gte dizzy as a sper as im going to use my xe injectors wiv a megasquirt v3.
 

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Discussion Starter #15
novadaz, I take it your making yours to suit the 16v head? from ur title it seems that way anyways?
The only thing you might struggle with is getting the round pipe - oval port shape.. how are you going to form the runner? i'd make it out of steel so u can give it abit of a bashing, ally might crack if ur rough? plus its easier to weld.
thankfully mine have round ports, so its not really an issue 4 me.
 
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