Dual Weber IDF 40's lacking top end power

[Brentonodon]

I've been tooling around with the ole baja for a few months now and am a bit disappointed at top end power, especially after reading about the Engle 110 cam and how it really wakes up from 2500 up to nearly 5500 rip'ems. My setup really isn't pulling that off. I've got decent power up to about 3500-4000 rpm and she seems to just not have anything after that. Went through and synced up carbs and set the best idle condition the other day which at least helped the engine get up to temp within a reasonable time but I'm now looking at a carb re-venturi and jet and want to see what you guys think before pulling the trigger.

The setup:
1915cc
Engle 110 Cam
dual port heads with dual spring
currently 28mm venturi with f-11 tube, 50 idle, 115 main, 175 air, and 50 pump jet.
looking to move to 32mm vent with 50 idle, 145 main, 200 air, and keeping the 50 pump jet for now (heard something about a 0 pump jet to help throttle response but not sure on that)

The biggest change I need is a little more power on the higher rpm range since currently she's having a hell of a time with even the lightest uphill grade. I know the tires don't help but there's gotta be more power to be had out of this 1915. Just gotta unleash it.

[tobiism]

are the heads ported? What gearing and size tires?
_________________
"There has never been a genius without a hint of madness."
-Albert Einstein

[Brentonodon]

I'm not sure on the heads being ported or not (inhereted it). Contacting the guy I picked it up from and seeing if he's got any more info on it so I don't have to tear it all down.

Info from my dealings with the dude before.
412 ring and pinion. Stock 1st thru 3rd late model gear and .82 4th.

[Fenix]

[Brentonodon]

Thanks, Fenix.

It definitely has been opened up and modified as 3rd and 4th were welded. Don't know if they changed any gearing other than 4th.

[tobiism]

The vents may help a bit but if your heads and exhaust aren't up to it I don't think you'll be revving much past 4500.
_________________
"There has never been a genius without a hint of madness."
-Albert Einstein

[Fenix]

I knew the description you gave sounded familiar. It is supposedly what the AH Trans-axle case in my rail was converted to. Only done test runs in 1 and 2 as I get this zombie running after sitting since 97. Though it feels like my 31x11.5s are almost too tall with the 1776 in the no more than 900lb rail.

http://www.mooreparts.com/vw-pro-street-flyer-tran...Al118P8HAQ

[Brentonodon]

Tires are also in the ballpark of 31" I'll double check that when I'm back at the house.

[Multi69s]

If it has a 110 cam and if it is a 1915, even if the heads are stock it should pull past 5000. It's time to do a plug reading. Run it wide open in third gear, push in the clutch, kill the engine and come to a stop. Pull a couple of plugs and check their color. I suspect that your jets are off.
_________________
69 road Bug 2110
73 Squareback - 2L, T4, Automatic W/ AC
Gone, but many fond memories 69 Baja Bug 2010 - 5 Rib Bus Transaxle
Gone but not forgotten 72 Baja Bug 2010
My builds
T4 into Squareback http://www.thesamba.com/vw/forum/viewtopic.php?t=458944&highlight=
Auto Trans Rebuild http://www.thesamba.com/vw/forum/viewtopic.php?t=516066&highlight=
AC in Squareback https://www.thesamba.com/vw/forum/viewtopic.php?t=...highlight=

[Brentonodon]

Thanks Multi. I went through and checked all the jets. only the idle jets match (stamped numbers that is) so I'm going to have to measure them to make sure some dingus before me didn't just throw in random sizes. Would you think that the 28mm vents would choke it up at that rpm?

My thought now is to measure all the jets, if they're all out of whack, install jets to fit the 28mm vents. Then, if that doesn't cut the muster I'll grab some 32 vents from my buddy and rejet for those. The joys of the carb life.

Here are the stamped numbers.
Cylinder 1: Main - 135, Air - 150, Idle - 50, pump - 50
Cylinder 2: Main - 117?, Air - 120, Idle - 50, pump - 50
Cylinder 3: Main - 11?, Air - 120, Idle - 50, pump - 50
Cylinder 4: Main - 115, Air - 175, Idle - 55, pump - 50

Imagine the confused look on my face when I opened those other ones up and figured that out. *concern intensifies*

[Multi69s]

Just my opinion, but without knowing the heads, I would stick with the 28mm venturis for now. My cam is not as hot as yours, but I am running 28mm venturis in my 2L Type 4, and it pulls hard to about 5,600. Over the years I have gotten more conservative when it comes to carb size. The advantages of a smaller venturi is that they are usually easier to tune, and you tend to have power now, versus a possible bog. What does the engine do when it peters out? Does it surge, like it is trying to rev higher, but can't? Or does it just hit a wall and stays there? I'm not there to hear it, but generally, if it surges you are lean.

I would give this company a call.

http://www.piercemanifolds.com/

They have excellent tech support. Tell them your specs, and they should give you a good starting point.

Good luck.
_________________
69 road Bug 2110
73 Squareback - 2L, T4, Automatic W/ AC
Gone, but many fond memories 69 Baja Bug 2010 - 5 Rib Bus Transaxle
Gone but not forgotten 72 Baja Bug 2010
My builds
T4 into Squareback http://www.thesamba.com/vw/forum/viewtopic.php?t=458944&highlight=
Auto Trans Rebuild http://www.thesamba.com/vw/forum/viewtopic.php?t=516066&highlight=
AC in Squareback https://www.thesamba.com/vw/forum/viewtopic.php?t=...highlight=

[cbeck]

My 2054 with 120 cam, 42x37 and worked ports is still pulling at 6000 with 28mm venturis.

[earthquake]

You cant always go by the numbers stamped on jets, somebody may have reamed or drilled out what ever they had on hand. you need a set of jet gauges, there are two sets [.45mm-1.5mm and 1.5mm-3.0mm] and there not cheap.

http://www.piercemanifolds.com/product_p/98.0135.00.htm

Here's a set of jet drills that could also be used for a gauge but I don't like using a drill on a jet unless you can do it in a drill press.

http://www.piercemanifolds.com/product_p/98.0181.00.htm

Casey
_________________
74 CLASS 11 LOOK-A-LIKE
69 DUNE BUGGY
79 INTERNATIONAL SCOUT II
05 SCION XB SERIES RELEASE 2[#437]
95 Chevy C3500 dually
98 Ford E150
Link to Kelly J. Nolte 3/20/53 - 11/6/08
https://time-zonelabs.blogspot.com/p/about-kelly.html
DEATH TO CHINGERS!
[From a military recruitment poster in the novel "The Stainless Steel Rat" By Harry Harrison]

[Brentonodon]

Sweet JEEBUS!!

Got the bajaraaaap mobile back together with the following setup:

28 vents
145 mains
200 air
50 idle
and 50 pump.

Runs like a bat out of hell now. The engle 110 really wakes that beast up around 2500 ripems as advertised. Then rockets from 2500 up to 5500 in no time and with no sign of stopping. PHEW, gotta shower and change the shorts now. It's amazing the difference just a few thousandths of an inch can make.

From 135 mains (measured) and 175 air (measured) to 145 and 200. DECENT! Thanks for tips fellas. Now I need to do the ole flat out under load plug test but so far so good. No popping, no weird misses, no lean spots. Just pure unadulterated power!!!!!

[Multi69s]

Great going .

I figured you'd like it once you got it sorted out. The 110 cam is a really good all round cam.
_________________
69 road Bug 2110
73 Squareback - 2L, T4, Automatic W/ AC
Gone, but many fond memories 69 Baja Bug 2010 - 5 Rib Bus Transaxle
Gone but not forgotten 72 Baja Bug 2010
My builds
T4 into Squareback http://www.thesamba.com/vw/forum/viewtopic.php?t=458944&highlight=
Auto Trans Rebuild http://www.thesamba.com/vw/forum/viewtopic.php?t=516066&highlight=
AC in Squareback https://www.thesamba.com/vw/forum/viewtopic.php?t=...highlight=

[Brentonodon]

Oh, also. Float bowl adjustment was way out of whack before. Could also be a major contributor. Set it to.the proper 10mm before compressing the ball and 32mm at full open. They had been close to 12-14mm at shutoff and 26-28 at full open.

[Brentonodon]

Here are some shots of the work done.

On the bench in the backyard. Only thing missing here is the coors.

From Espana!

78degree plates. What's the deal with the degree of the plate? Meant to close at a certain angle I'm assuming?

28mm Venturies View from the top. You can see the pump jet there as well.

Close up on the pump jet. 50 stamped on it.

F11 emulsion tubes and a 115 jet that was definitely not a 115 and is most certainly a 145 now. I engraved new numbers on so that if there's a next person going through it they won't be swearing as much as me.

Drilling out the jets on the lathe at the shop. Tiny whole, huge machine.

I'll shoot a video today of the tach during a drive to show how the motor is doing.

[Multi69s]

5 Jaw chuck, that's cheating
_________________
69 road Bug 2110
73 Squareback - 2L, T4, Automatic W/ AC
Gone, but many fond memories 69 Baja Bug 2010 - 5 Rib Bus Transaxle
Gone but not forgotten 72 Baja Bug 2010
My builds
T4 into Squareback http://www.thesamba.com/vw/forum/viewtopic.php?t=458944&highlight=
Auto Trans Rebuild http://www.thesamba.com/vw/forum/viewtopic.php?t=516066&highlight=
AC in Squareback https://www.thesamba.com/vw/forum/viewtopic.php?t=...highlight=

[Brentonodon]

Alright, so, really wanted to show you guys a vid of the bug ripping through the gears yesterday but for some reason it's not quite making the power it had on Saturday. Suspecting it's some crud in the idle jet on one of the cylinders. Going to dig into it tomorrow evening and clean those out and give it another shot. Anyone know the size of the idle o-rings? Trying to avoid paying amazon or an exorbitant amount of shipping. If no one chimes in I'll measure them and find a part number via McMaster or at least a dash number for everyone. Cheers

[Brentonodon]

Here are two vids showing part of the sync'ing process. Looks like I had the linkage to where it would keep the carbs the same at idle but when I'd hit the throttle the 3/4 carb was coming off idle before the 1/2 carb. A small adjustment on the link to the 1/2 carb sorted that out. One question I have is on your setup do both links that go to the carbs end up vertical? Mine is vertical on the 1/2 carb but the 3/4 carb is leaned a bit. Wondering if this is leading to my whole, not both open all the way at WOT.

Before adjusting. Both carbs read the same on the snail but on throttle the 3/4 carb lifts off idle first.
https://youtu.be/p8cQv6c1lmM

Adjusted the 1/2 link and got it to still be the same at idle but responds at the same time as the 3/4 carb.
https://youtu.be/3jxwqn3CzsI