Deep breathing...or how to put IDFs on your X

IDFs are configured for longitudinal motors but they have worked fine on my Xs ( I don't race or track day them). Most of my experience with dual Webers is with IDFs (124 spiders, 131, 128 and X. I have tried DCNFs several times and could never get happy with them. I have installed DCOEs (with appropriate cross brace mod) and found the linkage too fiddly. In my situation I had a pair of IDFs sitting in the basement and once I found a source for the manifold it was a no brainer.

Beware of "cheap" IDFs on ebay. No one gets new IDFs for $150...they are Chinese knockoffs and you will be sorry you ever bought them. There are lots of used IDFs that were used on VWs and they should work if you get the proper interlink.

Never tried IDFs on 1300 so no clue what the upper clearance is.
 
I'm not into the VW scene but I believe that's true. I know nothing about them in comparison to real Webers.
 
Kevin, the answer to your question is - yes - the bowl orientation on an IDF is "wrong" for a transverse mount. But unless you are pulling a lot of Gs in the corners it won't be a problem. For a racecar with sticky tires, maybe it would be a problem. For a street car, probably not.
 
Took brown X for a 15 minute drive yesterday. Wow, this thing really zings to red line (shaved head, euro cam). A/F gauge says my idle jets may be lean as cruising at light throttle has me around 15, 16 and hard accel shows 12.5-13.5 so my mains are probably a bit lean too. I'll jet up and hope to get out again today.

Oddly enough, my redX with the same carbs and header but stock motor is more of a torque monster...which is not a bad thing at all with the roads I drive on.

BrownX has header but stock muffler, wonder if that is robbing any power. RedX has a turbo muffler.
 
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Oddly enough, my redX with the same carbs and header but stock motor is more of a torque monster...
number one culprit is likely cam timing, your shaved (kojack) head has moved the cam timing away from optimal... the compression bump alone should have the engine making more torque than the stock 8.15:1 static CR engine by a noticeable margin

SteveC
 
Steve, when I built this motor with the Kojac head the timing mark on the crank and the stock cam pulley lined up perfectly so wouldn't the euro cam be timed correctly for my motor? I assume the euro motors used the same timing marks for correct timing as the US motors.
 
can't be 100% correct... you've shortened the distance between the crank pulley and the cam pulley but the amount shaved from the head/ cambox, which will rotate the cam anticlockwise compared to standard / non-kojacked head.

Cam pulleys vary in their markings.... are you using one of the pressed steel cam gears? I know they have at least two types with different timing mark positions (with white and red plastic inserts around the central cam bolt)

for the exercise, do you have a way of measuring manifold vacuum accurately? compare your two engines and I'm guessing you'll find the less torquey engine will have lower manifold vacuum.

SteveC
 
Wouldn't all US (and non US) 1500s have the same cam pulley timing marks regardless of whether it was the pressed steel or the one like I have which is cast with holes around the web? Maybe I'll get one of the adjustable pulleys but the last time I looked MWB was out of stock for the 1500 version. Maybe I'm looking at this too simplistically/
 
Wouldn't all US (and non US) 1500s have the same cam pulley timing marks regardless of whether it was the pressed steel or the one like I have which is cast with holes
No, as I said I know of at least two versions of the pressed steel type, with about 4 (cam) degrees of variation in the marking, and two distinctly different part numbers from Fiat. The DOHC engine is the same with variations in cam timing marks across the years.

That's why they have a procedure to check cam timing / phase... and quote open/closed values at specific lash clearances for "timing check" as tolerances can "stack up" and lead to reduced performance / increased consumption.

The vicks gear works OK, but be aware they are faulty, in that the machined recess that the camshaft nose resides in has been made too small by a couple of thou. The gear won't fit snugly (it will be too tight) onto the end of the camshaft ... the four I've used have all been the same. Easily fixed, but vicks won't want to hear about your problem.

the distance between the cam and the crank has altered from standard, that's a fact as you've shaved the head down by 60 to 80 thou. The belt is a fixed length (number of teeth) between those two points, so for the belt to fit the cam gets rocked anticlockwise (that retards the cam timing)

If you haven't changed the pistons, you should still have plenty of piston to valve clearance with the big flycut piston crowns, so I'd be inclined to fit an adjustable gear, and simply advance the timing by a couple of degrees. Via your butt dyno (and / or a GPS app on your phone doing some acceleration tests) you should feel the difference. A vacuum gauge would be handy to help find the cams sweet spot.

Notice I didn't mention degree wheels and dial gauges ... I think your cam is just a few degrees retarded now, and needs to be straight up or a couple of degrees advanced, so well less than half a tooth change... the outside of the adjustable gear will stay in the same place, you want to rotate the inside of the gear (and the cam) just a little clockwise from where it currently is.

SteveC
 
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They all function pretty much the same. I've used the Kent, Piper MWB and vics vernier gears, the vics is by far the cheapest to buy, so even with the hassle of having to strip them down and lathe the area in question so it fits, they still work out cheapest cost, I also lathe off the VAS on the front :)

I used a Kent anodised alloy gear on a build many years ago, and 20 years later saw it again and the gear was completely worn out, but I have no history on what happened in the interim, it looks like the alloy wasn't hardened enough, even though it was colour anodised.

I can't say how long the other brands may last as none have that many years on them... I think the ones Kent make these days are steel outer gear and alloy inner hubs, (the same as the Kent twin cam ones I use all the time) so that may tell you something... I don't think any regular aluminium alloy is going to outlast steel in this application.

SteveC
 
I don't know why vendors have such a hard time providing quality adjustable cam gears. I got one years ago from a known vendor and the locating dowel hole was too big allowing a lot of slop...maybe not that big a deal on an adjustable wheel but not a promising start. I decided not to use it.

Guess I'll start shopping for a decent one...if they are out there.
 
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