2110 Drivability

[Cave Man]

I have a 2110 that runs great wide open. But when you are just putting around town it doesnt run well untill you rev it north of 3500. The engine specs are below. I will also attach a dyno sheet that shows this engine in action.

2110
90.5x82
9.0:1
CB CNC Ultra Mag 42x37 heads
Duel Springs
1.4:1 Rockers
Steel Push Rods
FK8 Cam
CB Straight Cut Cam Gears
CB Light Weight Lifters
4340 CW Crank 8 Dowel
5.5 inch H Beam CB Rods w/ARP 2000 Bolts
12lb Flywheel
1700lb Kennedy Clutch & Plate
Mahle Piston & Cyl Pistons Balanced By Steve Sands
Port Matched Big Beef intakes
CB Super Case w/ 8mm chrome molly studs
44 IDF Carbs with update kits
CB Hex Bar Linkage
CB 1 5/8 Merged Fat Boy
Full flow with filter
1.5 qt sump
MSD 6AL w/MSD Dizzy & Coil


I have took out the update kits and set the float levels and that seems to have helped drivability some. I would like for it to pull better in the bottom end.

Any Ideas?

[Donny B.]

I'm probably the wrong person to answer this,  but you have big valves for small carbs.  I have a 2165 with 42 DCNFs and a K8 with 40x37.5 valve heads and lower compression (about 8 to 1) and my car will pull from 1800 RPM on top gear.  I can drive it like a stocker without issues.  Perhaps something is wrong with your combination.  Others with more knowledge will chime in.

[Cave Man]

Here is the Dyno Sheet.

[Cave Man]

Donnie, you are on the point. It is all about the combanation! I just cant see this not working better than it does. It will just fall on its face at lower rpms. I was considering a SVDA dizzy, a cam change to somthing smaller. I havent thought much about the valve size being a problem. Looking at the combo it is very near to what Glenn has excepth for the extra 70 cc's and the IDA's.  And he drives his car so it can be done. I just got to get the bottom end working better.

[Donny B.]

Looking at the AFR it appears that you are very rich just off idle and lean at 4k rpm.  You might try to lean out the idle jets and see what the affect is. 

[65bug]

A pair of ported Jeff Denham 40x35.5 heads would change all that!

[Ohio Tom (DdK)]

My .02.
The compression is kind of low for that cam. Adding 0.5-.075 to that will wake up the motor ALOT.
Flat spots  and soggy-ness kind of just go away when you add compression.

The heads are a little on the big side (sounds funny).
All that means is that you will need to tune farther than the normal jetting for those carbs.
Big heads will kill the low rpm velocity. Not really a problem as long as you embrace that and realize that you will have to jet things fatter.

Recommendations:
1. raise compression ratio. You'll like it for 2 reasons... Smoother running, and more HP thru the whole range. Your done.. No more transition issues...

Or...
2. istall the "zero bypass" accel pump inlet valve. and install bigger squiters to go with. Redline sells a "IDF tuning kit" that has all that stuff in one box.
Also, it comes with different idle jets.
3. Play with idle jet sizeing. Idle jets have alot to do with how a motor transitions to the main jets.
Sometimes you gotta go fatter to smooth out the transition. It's best to try these things and see how it drives with each change.

Lastly, run as much timing advance as you can down low.
Either a SVDA like mentioned above or modify your mechanical setup.
Often I modify 009 (or any Bosch) dist by limiting the advance to about 10 total. This means idle at 22, total at 32. That more initial advance will make a noticable improvement in motor responsiveness.
Also, If you have a "start retard" function on your box, you can just lock it at 32deg and it will run even better. (makes the idle sound bitchen too).

[Ian Godfrey]

I second all of Ohio tom's thoughts, I have and 86B (very similar to K8) and got it very smooth, 9.5:1. best for my engine was 18 deg idle and 28 all in by 2 thou rpm. Every engine is different so try more idle and more all in like tom says as well and see what your engine likes. I have IDA's not IDF's but worked a lot on idle jets and emulsion tubes to get the transition right. Took a few weeks but worth it to get nice.

[jgerock]

Tiny grain of sand advice..

I know next to nothing about 2000+cc VW engines, but have learned a lot from talking to Gene Berg and reading his articles about engine building.

Reviewing your engine specs, it looks like a "race" version ill-equipped for the street-slugging around in 3rd gear.  Lots of CFM and a big cam for high revs.  Gene was always against high compression ratios - especially on street-driven VW's.  I'd suggest a different set of heads with smaller valves (40x35.5) and ports, less radical camshaft and re-tune the carbs to suit the new combination. 

[Cave Man]

Yesmit was built to turn high and go fast. But it was built for someone else and it is now mine. I love to go fast but have made it to another point in my life. It is goodmto know I don't have to spend a grand or more to make it more streetable.

[maui]

bigger idle and maybe smaller air and retune at running temp.

[Brandon Sinclair]

Looks like a tuning issue according to your AFR print out.

I agree with everyone that a faster advance would help and maybe more initial timing.  It is easy to tweak stops and springs in a distributor to get what you want.

You are very rich in transition.

What size jets are you using and did you measure them to verify the sizes are correct?

Before you start jet tuning make sure you ignition is set the way you want it and that you have adjusted your valves, synched the linkage, verified the fuel pressure and your float settings and checked for intake leaks.

Jet your idles first-pull the main jet stack and run the engine in the idle jets only.  Change the idles and readjust the mixture screws each time you change them and see what happens.  When the engine will no longer run and spit you know you are too small and go back to the next larger size and readjust the mix screws and you are done with the idles.

You are way rich in transition which means the airs are too big.  Go down at least 20 on those.  You will have to adjust the mains to compensate for the air jet change since there is a relationship between the two jets and you want to be around 13AFR across the board when you are on full throttle.

[Dano382]

Looking at the AFR it appears that you are very rich just off idle and lean at 4k rpm.  You might try to lean out the idle jets and see what the affect is. 

Am I missing something? I see it running pig lean, then going fat at 4k. Looks to mean it's leaning way out in the rpm range he's having trouble with then when it's transitioning to mains (3500rpm) it fattens up and runs fine. He never said what venturies, jets, tubes he's running. If my motor see's 14-15afr it stumbles hard. I think it's a jetting issue.   

[Cave Man]

From the time this shhet was run I have taken out the CB update kits and back to 36 vents with the stock Aux Vents. it got better with adjusting the fload levels but still was not good in the bottom end. The engine is out of the car now and Im going to bump the compression to around 9.5 and then put it back in the car. It was in the 62 that I only drove for fun. It will now be going in my 70 nthat is my driver car. I would like a smooth pull from around 2k on up. Thanks for all the info. I was going to get rid of it and start over but it it all brand new with 500 to 1000 miles on it. Hate to have to start over.

[Dano382]

Looks like a tuning issue according to your AFR print out.

I agree with everyone that a faster advance would help and maybe more initial timing.  It is easy to tweak stops and springs in a distributor to get what you want.

You are very rich in transition.

What size jets are you using and did you measure them to verify the sizes are correct?

Before you start jet tuning make sure you ignition is set the way you want it and that you have adjusted your valves, synched the linkage, verified the fuel pressure and your float settings and checked for intake leaks.

Jet your idles first-pull the main jet stack and run the engine in the idle jets only.  Change the idles and readjust the mixture screws each time you change them and see what happens.  When the engine will no longer run and spit you know you are too small and go back to the next larger size and readjust the mix screws and you are done with the idles.

You are way rich in transition which means the airs are too big.  Go down at least 20 on those.  You will have to adjust the mains to compensate for the air jet change since there is a relationship between the two jets and you want to be around 13AFR across the board when you are on full throttle.

Brandon is correct on this........  

[Dano382]

From the time this shhet was run I have taken out the CB update kits and back to 36 vents with the stock Aux Vents. it got better with adjusting the fload levels but still was not good in the bottom end. The engine is out of the car now and Im going to bump the compression to around 9.5 and then put it back in the car. It was in the 62 that I only drove for fun. It will now be going in my 70 nthat is my driver car. I would like a smooth pull from around 2k on up. Thanks for all the info. I was going to get rid of it and start over but it it all brand new with 500 to 1000 miles on it. Hate to have to start over.

I'd leave the compression alone, yes just a tad low for that cam but not that bad. I have .600" at the valve with only 9:5.1.....36mm vents way to small. Rule of thumb 2mm smaller then your intake valve maybe 4mm to help with the low end. I'd leave the motor alone with only 500-1000k miles and focus on tuneing.

[John P]

I would not take it apart or spend a dime on it, and agree with the consensus above that it is likely a tuning issue.

For example, my motor is very similar to yours, with the exception of the following:

40 x 37.5 Denham heads with generously ported intakes
1.5 inch Berg header and single Quiet Pack
IDAs with 37 mm vents
Stock-length rods

As you can see from the above differences, mine is a street engine and I was primarily concerned with port velocity (vs high RPM HP). The K8 is a wonderful street cam with great manners and one hell of a wide power band on a properly tuned engine. There is no need to rev it to the moon, because it pulls so strongly from relatively low RPM. My combo drives as smooth as a kitten and accelerates like a raped ape, pulling from 1800 RPM in 4th gear going up a hill without bucking or detonating.

Yeah, your valves are a bit bigger than I'd run, and I'm unclear on your port sizes. As noted above by others, I'm sure that you can get it to run smoothly by spending time with the carbs and a AFR. Be patient, and don't throw out the baby with the bathwater.

My 1.5 cents.

JP

P.S. If you start driving that thing every day and get sick of the racket from those steel pushrods, I strongly recommend heavy duty aluminum pushrods. Night a day difference (in noise), and much lighter to boot.

I hate steel p/r on a street engine. 

[Cave Man]

One thing that needs to be done I'd the pushrods. They are loud and were just cut by hand. I do intend to get the valve geometry set up properly and a set of pushrods cut on a mill so they are spot on.

The ports are very large. A stock intake gasket will not cover the port! They a big beef manifolds with slot of porting to open them up to match the heads. Oso the port velocity is not going to be good on the bottom end.

I got my eye out for some smaller heads with a good port job if anyone is looking for a traid.

Talked to the man that built this one and the compression is not 9.0:1 but is 9.3:1 static. It is a bit better.

Thanks for all the ideas. I wil get this back in the car and get to tuning! I did take out the CB Update kits from the carb a but didn't get it back to the dyno for some tuning and not just a baseline pull. I just got frustrated with it and left it on the carport after I sold the car it was in. Sounds like I need to ge back on the program.

[Cave Man]

John what pushrods are you running and where can I order them? I would like to get a set.

[arnolds64]

I have 2017 with a 130 Engle. 308 duration and less lift at 461 than the K8 with 043 40x35 Mexicans that I hand ported. I am running 44's with 55 idle jets, 36 vents, 200 Airs and 155 Mains. Looks like you may have a problem with the combo. I would go larger on your Vents and check the idle jets to get it leaned out at the 2000 rpm to 3200ish ranges. Those heads need more air. Maybe go 1 step up on the Mains as it looks a little lean up top to me. Oh also go ahead and bump the compression. If you do not have the rocker geometry right this could be screwing with your cam and how it is working with the whole tune of the car. By the way I have the Aircooled.net pushrods and they are stock quiet. Expensive but I think worth it.

I am running 9.9.1. Of course I would run 91 Octane all the time. My car runs very linear with nice power down low. At about 4500 it really comes on strong and pulls with power to 6500+.  

[John P]

John what pushrods are you running and where can I order them? I would like to get a set.

I've run H/D aluminum pushrods from both Berg and Aircooled.net, and have been very happy with both. Buy (or make) an adjustable pushrod, and using a dial indicator to determine the required length, order a complete set from either of them. Both companies made them to spec when I ordered them.

You will be MUCH happier with them.

JP

[Dougy Dee]

That low rpm driveability problem sounds like an issue I had tuning a customers 1776 with 42 x 37.5 044's and 44IDF's. Ran like a scared cat at WOT but was miserable and balky/lurchy at cruising/driving speeds. Even dropping down to 32 vents didn't help.

Searched around and found the throttle plates opened up a long way to get the engine to idle. This uncovered the 3 or 4, I forget, transition ports. After some contemplation I drilled out the throttle plates, to about .080, and ALL the problems went away. Now the car's a treat to drive like a granny or a madman...

[arnolds64]

Sorry I noted the Mains for my 44's were at 145 but actually they are 155's.

[neil68]

I ran the same combo, except 78.4 mm crankshaft (2017 cc) and IDA's.  This was very smooth at all rpm's and came alive above 3500.

I agree with the other posters that this is carb/tuning issue.  The 42 x 37 Ultra Mag Plus heads and FK8 are not the problem.  Good luck!

[mgmahaffey]

I just completed my 2110cc for my 1970 Ghia Convertible. I built it myself with considerable help from Steve and Greg Tims. My main objective was to have a very drive-able cruiser, being a Ghia convertible. So, much to the shock of my fellow DKP'ers I went with - upon Steve Tims' strong recommendation - an Engle 100! That was almost sacrilege with my buddies. Any way the heads are Steve Tims Stage 1 Plus 42x37 043 Mexican. Compression is 8.1:1. Stock ratio rockers 1:1. Every other spec is similar to yours just different brands. Also running heater boxes 1-5/8" A-1 Sidewinder exhaust. We broke it in and dyno'd it at Tims' place. Chose a great day to do it - August in So CA, 101-degrees, 20% humidity, 1000-ft elevation - not the best for making HP. That makes the correction factor 1.0904 according to Stuska Engineering's calculation sheet. Anyway, we were pleasantly surprise with the power it made, particularly at 6000-rpm for an Engle 100 and it still wanted to pull, but we had no reason to push it higher. The objective was to jet it and break it in. Here are the figures (fan belt on, stock size pulley):
3000rpm 72-hp
3500rpm 91-hp
4000rpm 105-hp
4500rpm 113-hp
5000rpm 120-hp
6000rpm 124-hp
Fan Belt off
6000rpm 141-hp

While it's not a fire breather (been there, done that) it drives incredibly smooth from off idle all the way up. I can go over speed bumps by my house at 15-mph in 2nd without having to put in the clutch and accelerate away without any sign of bogging. It idles low and smooth, can sit in traffic no problem. I'm happy. Better than I would have thought using an Engle 100. I guess Steve Tims knows what he's talking about.
Mike Mahaffey

[martin]

I've run H/D aluminum pushrods from both Berg and Aircooled.net, and have been very happy with both. Buy (or make) an adjustable pushrod, and using a dial indicator to determine the required length, order a complete set from either of them. Both companies made them to spec when I ordered them.

You will be MUCH happier with them.

JP

Does Berg now sell Al pushrods? I looked on their site and didn't see any, and I remember the quote that is still on their site:


Any type of aluminum pushrods should never be used with any stronger spring sets and higher performance camshafts. They will always flex excessively and eventually break. The breakage will depend upon how fast a ramp the cam has, how strong the spring is and how high and often you turn the engine. Play it safe with Berg pushrods that do not fail.

I have the Aircooled.net ones (straight).