New engine conversion/Bike carbs

BIG4244 · Post by **BIG4244** » Fri Nov 30, 2007 8:32 pm

Heres a few pics of my on going engine swap from a 1.4 8v (AEX) to the 1.6 8v (AEE) with fast road cam, ported, polished and skimmed head, 4 Branch manifold (when i buy it!!!) Custom inlet manifold (by me) and yamaha R6 carbs.

Is anyone one the forum running bike carbs???

The Bare Block

The Manifold Beginings

The Near Complete Manifold

I will post more pics when the head comes back and when ive fitted it (soon hopefuly!!!) let me know what you think.

JarnoVWPolo6N · Post by **JarnoVWPolo6N** » Fri Nov 30, 2007 8:58 pm

Don't run carbs myself, not planning to, but know a lot of people who do.

Looks good so far, don't make the inletmanifold too long, or you'll hit the "back of the dashboard". And why did you choose the R6 carbs? Mostly people I know choose Keihin's or Honda SC50 or SC57's (Sorg Motorsport itself runs it's 1300 16v motorsport Polo on SC57's)

What cam you using? and what is the diameter of the throttles in the R6 carbs? any match with the inletvalves?

JarnoVWPolo6N · Post by **JarnoVWPolo6N** » Fri Nov 30, 2007 9:01 pm

BTW, looking and the head on the last pic, very, VERY nice job on the head-work, those are some massive ports m8

Increased mine (also a mk4 1600 head) up to this:

Didn't go any further afraid to hit some oil- or coolantchannel, but from the looks of your I could have gone a sh*tload further

BIG4244 · Post by **BIG4244** » Fri Nov 30, 2007 9:14 pm

Well the R6 carbs are 36mm, and the standard inlet ports are 32mm, but once ported should be bigger any, so i thought that the R6 carbs would b e perfect once set up properly, yeah ive measured the manifold and its just long enough to get in there with a filter and more space, just enough to not hit the bulkhead, im going to be running a newman cam. Oh and the head in the last pic is actualy off of a 2.5 TDI T5 transporter!, sorry mate i wouldnt open your head up anymore! i hope mine looks like yours in the end!.

JarnoVWPolo6N · Post by **JarnoVWPolo6N** » Fri Nov 30, 2007 9:33 pm

Looking back at that head the second and third port are indeed to close for a Polo's head

whoopsy, didn't pay attention

36mm isn't that big for carbs, but it's not to small either

inletvalves are 35,6mm, so roughly 35mm channeldiamtere, the 36mm will be sufficient to not form a restriction on the inflow of air. Most people I know drive 37 or 38mm carbs, but that's just to "have spare capacity"

Any mod's on the blokc itself to be made? (pistons, pistonrods etc.?) I'd recommand a lightened flywheel, will give that extra rise in rev's once you hit the gas

and flatten the head a bit, got mine flattened couple half a mm, to raise my compressionratio to 10,5:1 instead of my original 10:1, your AEE engine has 9,8:1 original, so flattening the head and raising it will gain you more BHP and torque again

and that's what it all about isn't it

BIG4244 · Post by **BIG4244** » Fri Nov 30, 2007 9:42 pm

Haha yeah thats a 5 cylinder!

, yeah the heads going to be skimmed abit, and i was going to lighten the flywheel but ive heard alot of horror storys about them exploding?

JarnoVWPolo6N · Post by **JarnoVWPolo6N** » Fri Nov 30, 2007 10:46 pm

BIG4244 wrote:Haha yeah thats a 5 cylinder! , yeah the heads going to be skimmed abit, and i was going to lighten the flywheel but ive heard alot of horror storys about them exploding?

b*******s, that can happen, but only on engine with extreme performance (for instance plus 500 bhp) and lightened to beyond the extreme.
Mine is lightened over a half a kilogram, and the weight is reduced on the outer part of the flywheel (the farthest away from the centre which is on the crankshaft), there the effect is the greatest, but since it's not lightened extremely it's still driveable (low risk of the engine shutting down when kicking in the clutch and the engine loosing rev's to below it's idle point)

BIG4244 · Post by **BIG4244** » Fri Nov 30, 2007 11:52 pm

i think ill consider getting mine done again, is there a great gain from it??

JarnoVWPolo6N · Post by **JarnoVWPolo6N** » Sat Dec 01, 2007 8:31 pm

BIG4244 wrote:i think ill consider getting mine done again, is there a great gain from it??

It will decrease the "powerloss" in the drivetrain, doesn't increase performance, but does make the engine climb faster in rev's and decrease the loss of torque to get the flywheel spinning, which are now transferred onto the wheels

LeMeph · Post by **LeMeph** » Sun Dec 02, 2007 11:56 pm

im so glad someone near me is doing this now i know who to come bug when i get round to it

Out of interest how do yuo set it up? Do you need to fiddle with the ecu or anything? Im sure there are some plugs going into the mpi unit is why i ask as im guessing if you unplug them something unpleasent could possibly happen? Though i know little so bleh... im clueless lol.

You say you made the manifold yourself? Dont suppose when the time comes you could do me the honours aswell?

Wouldnt have the first clue where to go and get one made. Also... i know alot of questions... wait.. new paragraph!

How much did the carbs set you back and whered you get em from? Questions questions questions... Sorry for the long winded post, your looking for answers and im throwing in the opposite lol.

BIG4244 · Post by **BIG4244** » Mon Dec 03, 2007 9:51 am

Ok, where do i start!, the carbs were Â£35 off of ebay, on the injection side of things, these are purely carbs, not throttle bodies so you can bin all the E.C.U and injectors, im going to run golf mk2 engine loom, ignition amplifier and coil this gets rid off all the fuel injection, you need to lower the fuel pressure down from about 3bar to 2.5p.s.i, and then get jets to suit the engine size, for example 1600 engine need 1.65mm jets, i drilled out the original r6 ones and then just get somewhere decent to put it on the rollers and set them up, you can get a manifold made for Â£200 to your door, but im abit tight so made my own!! the materials cost me Â£30 and just many hours to make it, also you need to run a manual choke, visit this http://www.totalvauxhall.co.uk/resource ... h60697.pdf

ill keep updating the post when i get further into it, any more questions, you know where to find me!!

LeMeph · Post by **LeMeph** » Mon Dec 03, 2007 10:55 am

thats an incredibly informative little page there!

Cutting the ecu out of the equation ay... fair enough lol.

Definately keep this thread updated i know theres atleast one other person on here who will be interested in this. Thats if phat controllers polo still lives lol

JarnoVWPolo6N · Post by **JarnoVWPolo6N** » Mon Dec 03, 2007 1:22 pm

Just wondering, how is the emmision regulated in the UK? Here in Holland you are obliged to get a annual check-up of your emmision, if it's too high, you can't drive your car on the public road anymore. That's one of the main reason I'm not ever installing them on my mk4, since them I'll have a fairly huge chance of not passing my emission-test and get banned from the public road

BIG4244 · Post by **BIG4244** » Mon Dec 03, 2007 3:37 pm

We have a yearly test called an M.O.T., and in that is an emissions test, but i think if the carbs are set up good enough it should pass it, or lean the mixture off just before you have the test??

JarnoVWPolo6N · Post by **JarnoVWPolo6N** » Mon Dec 03, 2007 3:54 pm

BIG4244 wrote: or lean the mixture off just before you have the test??

should work yes, be carefull not to drive this way too long or you'll fry your pistonrings. But dunno how big the marge on the emission on that MOT is, but the marge overhere isn't quite large, I already have to mount back my cat for our test (called APK

) and fear a bit for the cam+fuelpressure, but the latter can always be downward adjusted of course