TheSamba.com :: View topic - No low-end torque.

Wed Aug 21, 2019 3:20 pm

I have a 2006cc motor that pulls strong over 2500RPM and powers up almost any smooth steep hill if I keep at 3000 or so. Never powers out if I keep the RPMs up. But on a rocky trail it's a dog. Diff is 4.37, tires are 205s (27")
It's in a full-body class 11 look-alike, so weighs ~2800lbs.

Engine has dual Weber 44's. I think the dizzy is a Petronix. Has been tuned up by local experts. It runs strong around town and on the interstate. However I bought it hoping to run easy jeep trails. I had a stock VW Thing at one time and it had way more torque in 1st than this bug, with about the same size tires. Engine was built at sea level but carbs are now rejetted for 5,000 ft.

I can't help but think that there's a simple explanation for the lack of low-end torque. If anyone cares to wade through the engine specs see below.

Any suggestions are greatly appreciated.

Steve Tims Stage 1 Plus heads (per his ad - Ideal torque head for stroker street and off road engines )
42x37 valves, hi-rev springs, swivel feet, solid shafts, 1.25 rockers.
(Alt info says Empi solid shaft rockers with swivel adj., 1.25 was crossed out)
Aircooled.net’s heavy duty aluminum push rods
90.5 Mahle pistons, B stroke, Teflon buttons
CB Performance cromoly rods
Scat counter-weighted crank (78mm)
Stock weight flywheel, 8 dowel w/ Scat gland nut
Balanced rotating assembly
Engle 110 cam (a samba post says an Engle 110 cam has 383 lift at cam. 236 duration at 0.050 range 3500-5000) See exhaust.doc
8.5:1 compression
009 with Compufire (next owner may have changed this). 2011 build photo showed Dist with vacuum adv, now w/o.
Rob said it had a SVDA on it when he sold it.
Weber 44 IDF’s, made in Spain (completely rebuilt with Jet Dr’s hardware, etc)
On 4-22-2011 with dual carbs Robb claimed: 36 venturis, 50 idle, 145 main, (200 air corrector jet)

Wed Aug 21, 2019 3:53 pm

What size exhaust? Without knowing, and I'm just guessing, I think it's too big, along with the carbs.

If I was setting that up for dirt,

Webber 40's or HPMX
1 1/2" exhaust, no bigger.
1.1 rockers

Wed Aug 21, 2019 3:55 pm

Too much cam, and not enough compression, especially at your altitude.

Your carbs are also huge for the smallish displacement when its torque you want. Airspeed through the intake is what you are after.

If it were mine I would swap to 40mm IDF's with 32mm vents, change the cam to a Web 218, installed on a 106lc, and bump the compression to 9.2, w/ .040" deck height. A good 1 1/2" header also.

Brian

Wed Aug 21, 2019 4:11 pm

Those are NOT good "crawler" heads. Way too much exhaust flow for the engine and type of driving. also, for altitude the jetting sounds rich, but what do I know.
What Brian said, - SPANISH 40 IDF 70/71. 40 HPMXés wohnt do much difference. Then you might as well just install 32 mm venturies in the existing carbs. (Reduced intake manifold volume recommendable) Web 218/119 on 106ILC. No more. CB 2241/35 would also be a good option.

Wed Aug 21, 2019 4:52 pm

I forgot about the 218/119! That would be perfect to tame the exhaust.

Another option that will help a little would be to swap on some 94's. That would increase the displacement, increase the compression, and help tame the cam duration down some. Small vents would still be needed, but it will make the 44IDF's better suited.

You can have the cylinder bases turned down to slip into a 90.5 case. also.

Just another option.

Brian

Wed Aug 21, 2019 9:27 pm

Engle W110 "284 degrees of advertised duration, and 247 degrees of duration at .050", on a 108 Lobe Center."

IMHO 284 degrees is a mild racing cam. Don't expect much from it below 2000 - 2200 RPM.

Thu Aug 22, 2019 3:50 am

drop the vents to 32mm-34mm, if ur not worry about doing 90mph on the free way :wink: that cam will be ok,,

Thu Aug 22, 2019 6:37 am

I agree with basically everyone above. It's really your combo that is off. A W110 can pull with the right heads, carbs and compression. Those carbs can pull hard with the right cam, heads and compression. Those heads "could" pull much better but they would never really be considered "torquey"

So you're options are leaving the cam, putting heads on with 40x35.5, upping the CR and putting on 40IDF's OR upping the cam, upping the CR and upping the engine CC's if you want to keep the heads and the carbs.(and that still may not be as "torquey" as you want.....

Thu Aug 22, 2019 7:50 am

I agree also with whats stated above but was the cam degreed when engine was built if so if it has a degreeable cam wheel advancing it 4degrees may help or if it wasnt degreed when emgine was built it may be to retarded i have seen engle cams all over the place when degreeing.

Thu Aug 22, 2019 9:26 am

My 2006cc pulls like a tractor from 1500 rpm.

40 Hpmx with 32 vents, C25 cam, 1 1/2" exhaust, CB 044 40mm/35mm heads, 1,2mm deck, 9,5:1 static comp.

Thu Aug 22, 2019 9:55 am

my old bug had the taller tires, 44 mm carbs, 3.88 gear more cam...lot more head work...and had real good power all the way up... as for a quick fix...find somebody that knows vw's real well to go over it. I kinda doubt it can be foxed over the computer unless ...something like your tune is way off and dist is at 3 degrees untill 3000 rpm and advances then. you may need to check the addvance and see what it si doing.possiably put a known good performance dist in. but I think it ,might need toe entire engine gone through and made right for the intended application.yes I know you dont want to do that. you may also have cloged idle jets and knot know how to tell it does..we have no idea on your ability or lack of. ears&feal are important.and how to use them is the key.

Thu Aug 22, 2019 10:37 am

Cut the heads to add some compression, I'm running 8:1 with a 110 on a 1835 and wish I would have went 9:1 or a bit more.

Thu Aug 22, 2019 10:42 am

Cam runs out of breath way before the heads, so it's just wasted flow, and you've lost airspeed in exchange. Not a happy combo. I would change the heads, and then, if you want a really nice combo, the cam.

Thu Aug 22, 2019 11:07 am

I have a 1904 with a 110, 40HPMX carbs, 9.3:1, non-poorted 40x35.5 Revmaster heads, stock flywheel and it's a bullet out of the hole in my buggy.

brad

Thu Aug 22, 2019 2:22 pm

Make sure your advance is coming in like it's supposed to. It will be gutless as hell on the bottom end if it's not.

Thu Aug 22, 2019 11:29 pm

Hate to say it but I'd want to swap the heads, it's just a bit too much overkill.

My daily driver 2007cc is FARILy sporty, based on my experiences the next heads will be 40x34.5 valves, cam between engle 120 and 125 9.5-1cr
That's where it's at IMO. MAYBE it's the altitude, partly. For a LOW rpm engine even milder.

Those Tims might be great heads for SAND, or desert, weekend warrior street car...... sand you NEVER have enough power gotta REV it out, but doing jeep trails at 2x jeep speed it's more about control and good response. power WHEN you need it, can't see around the turns and trees, and your always in the wrong gear. Sound familiar? :wink:

Fri Aug 23, 2019 8:43 am

Puting 32vents in will upper the velocity adding torque but a 2liter with a small e110 should have good torque even with those heads the 78 stroke should over ride the size of those valves with a 110

Fri Aug 23, 2019 9:09 am

I have the same size engine with the same heads and carbs as the OP in my micro. It pulls like a tractor, i have a Web 218 and 1 1/2 exhaust and a little higher compression (8.5 to 1). Cheaper to change the cam than the heads.

Mon Aug 26, 2019 10:19 am

OP here. Sorry for the delay in responding. Went camping.

I appreciate all of the great advice; obviously from folks who know what they're talking about.

One poster asked about my skill level. It's pretty low, and there are no shops within 250 miles that could go through the engine. Not that I wouldn't haul it to SLC or Denver to get the work done.

Maybe I'll start with the vents and exhaust.

Here's a photo of the exhaust on the car. The grey tubing on the exhaust is 1.5" OD. Behind that and to the muffler is 1.75" OD. I think the muffler may be a turbo muffler, but I wouldn't mind a quieter one. The muffler shop showed me a smaller muffler that they said would be quieter. Would this hurt or help low end torque?

I know TMI but I ran the car up a steep highway grade from 7000 to 11000 feet and it ran strong, even at 11000. Ran cool (oil temp 200, head temp 325) with 1.5q sump, oil cooler/w fan, external oil filter, going 50 MPH at 3500 RPM in 3rd gear, going up the steep grade. Sometimes missed like it was starving for fuel.

Mon Aug 26, 2019 11:01 am

Are the heater boxes stock or a high flow version with 1.5" tubes inside ?

Olli