Harney's diatribe - rocker geometry to install & beyond

mharney · Post by **mharney** » Tue Dec 21, 2004 5:33 am

The readings were taken off idle, at about 2200 RPM. The mixture screw is not really in question here, since it does not have much to do with what's going on at that speed with the butterflies opened. The idle jets do though, and I have a set of 60's coming, and have a set of 65's being reamed as well. I'll have the 65's this morning. Bulletins as they occur.

You guys need to read up a bit more on how to tune Webers btw.

mschilling · Post by **mschilling** » Tue Dec 21, 2004 5:34 am

Mark, between idle and when the idle jet takes over, the transition ports provide the mix, and that is not user adjustable.

mharney · Post by **mharney** » Tue Dec 21, 2004 6:42 am

Yep, I realize that. The only way it is is through the use of drill bits, which is right out for me.

mharney · Post by **mharney** » Wed Dec 22, 2004 10:12 am

Well, I put in a set of 65 idles, and man O man.. You know what it sounds like? It sounds like a BIG HIGH COMPRESSION bike engine, with the exception of the very loud timing gears and the 4 barrels giving a fairly healthy bark even through the air cleaners.

Once I get the accelerator pump circuit squirting the right amount of fuel at it, I should be close to the right state of tune. The mains are indeterminate, obviously, since it is still sitting on a stand.

Oil pressure is very high (like 70 lbs at 3000 rpm), and temperature never really gets down to 180 sitting on the stand. I'm going to block off the hose to the oil cooler (DTM shroud) for a while and see if the pressure drops and temp goes up. My sensor is on the pulley side oil relief valve - it's the plug.

mharney · Post by **mharney** » Tue Dec 28, 2004 3:05 pm

Yesterday I got a chance to start up with no oil cooler airflow and let it run about 20 minutes before it got close to 180. It never made it to 180, but it sat right under it, even with no airflow.

I got my idle jets (60's) from John C., and I think he was right on with his eduguess. It runs a steady 14.0 at idle and 14.5 just revving up a little. Having the engine out in the open makes a HUGE difference in my ability to tune the thing, and due to its ease, it has restored my faith in the tuneability of these carbs, and has definitely furthered my understanding of them. So far we are at 60/160/180 with F2 tubes. No load on it so far, but readings are good.

Gauge says cylinder head temps reach about 325-330, and it is about 50 degrees outside, so maybe closer to 300 on the heads, off idle and right around 2000 RPM most of the time. If I let it sit and idle low, CHT goes to 350. Start revving it up and it goes right back down.

Short term plan is to chase down any remaining oil leaks, retorque heads second time, and adjust the valves, change the oil, and start prepping for installation into the car. I still have to change out the fan for the welded one.

The exhause slipjoints leak, and that bugs me. I can't get the clamps that are on it tight enough to seal. What should I use in the joints to seal it up?

This CB Linkage has been nothing but difficult to work with since I got it. It needs more stability on the linkage arm that goes on the carb, and it needs better quality linkage arms on the hex shaft. The little set-screws they set up on them are not strong enough to torque the arms down to the rods correctly. The threads stripped out on mine before I could even tighten them down all the way. I think the best thing to do with them is to open the holes up for a larger diameter screw (or a plug) that will bottom against the face of the hex bar linkage, or even do two of them per arm. That would resolve that part. The throttle arm they supply is flimsy, and the pull on the offset rod puts torque on that little arm, twisting it slightly. Over time it will weaken. Needs a stronger one. The down rods are ok, a little stiff, but I would rather that than too loose later when they break in. I don't like the way it is made to apply spring pressure to the rod to center it on each end. Seems like a lot of pressure to be applied against the intake joints to the head, because that is the part that sees the most effect. I think just adjusting the ends close, greasing it and running it is my best bet.

Steve Arndt · Post by **Steve Arndt** » Tue Dec 28, 2004 4:57 pm

Mark,

On my CB linkage I drilled the holes deeper where the springs fit into the linkage bases that center the cross bar. Since I have narrowed my engine .160" with the huge flycut for my squishies this is what it took to get it to work smoothly. (you could also shorten the springs on each side). Put a little grease on the springs too. Use silicone spray frequently on the ball ends to keep them sealed up and and smooth.

I have had similar low oil temps as you on my ss project, and I only use stock EFI 76 bug cooling tins (not dtm).

The fuel demand of your engine is amazing, 60 idle jets in idfs, wow.

Steve

mharney · Post by **mharney** » Tue Dec 28, 2004 5:07 pm

Yeah, it seems like it sucks it down pretty fast just playing around too. 60 idles on 48 IDF's with 40 vents. I heard about 1.6x vent size is a starting point.

mharney · Post by **mharney** » Mon Jan 03, 2005 2:04 pm

Steve Arndt wrote:Mark,

On my CB linkage I drilled the holes deeper where the springs fit into the linkage bases that center the cross bar. Since I have narrowed my engine .160" with the huge flycut for my squishies this is what it took to get it to work smoothly. (you could also shorten the springs on each side). Put a little grease on the springs too. Use silicone spray frequently on the ball ends to keep them sealed up and and smooth.

I have had similar low oil temps as you on my ss project, and I only use stock EFI 76 bug cooling tins (not dtm).

The fuel demand of your engine is amazing, 60 idle jets in idfs, wow.

Steve

I've done something worthwhile related to the CB linkage. Mine had 1/4-20 set screws for the arms, and let me tell you, they are wimpy. You cannot tightem them down enough to get the arms tight and not wiggling. They stripped on me.

So I got a 1/4" drill bit and a 5/16 tap, and resized the holes and used 5/16" set screws. My threads are a lot better than the originals, and the set screws can be tightened plenty. The 5/16 tap really calls for a 0.257" drill, so 1/4 worked fine.

Regarding the engine, I have it all set up with the new welded fan (Thanks to John C., much better than the other one I had), and have the linkage set up to work properly, I think. I have a CB Weblink kit on the way and I am going to get set up with that and test a little before I install the engine in the car. I went ahead and pulled all the stainless firewall I had in there, because I don't think this engine is going to fit with that in there.

So.. once I get the Weblink kit installed I will be installing the engine in the car. Maybe the end of this week.

mharney · Post by **mharney** » Thu Jan 06, 2005 8:58 pm

Man, last few days here have been the pits. Check these out! Lost cable, hence internet, and that's it, but I heard 80,000 homes with no power on the radio news.

http://bouncewithme.bounceme.net:81/ice01.jpg
http://bouncewithme.bounceme.net:81/ice02.jpg
http://bouncewithme.bounceme.net:81/ice03.jpg
http://bouncewithme.bounceme.net:81/ice04.jpg
http://bouncewithme.bounceme.net:81/ice05.jpg

So needless to say not a lot of opportunity to work on the engine. I did get some last changes made to the fan and alternator, and need to clean up the underside and start it one more time for a good oil warmup and to check for leaks one more time. MUCH easier to deal with out on the stand than in the car.

Got my pair of 36 IDFs from Gabriele in Italy, and have started working to get them ready for my bus engine.

EASY RIDER · Post by **EASY RIDER** » Thu Jan 06, 2005 11:54 pm

Wow! The first pictures of Hell freezing over.

Bert

mharney · Post by **mharney** » Fri Jan 07, 2005 7:40 am

You got THAT right. Helltown.

Bugzlife · Post by **Bugzlife** » Fri Jan 07, 2005 7:49 am

see if the decibles from an open header vw at 6-7k will cause the icicles to break loose off those trees

vdubsinjensen · Post by **vdubsinjensen** » Fri Jan 07, 2005 9:53 am

Hey Mark,have you tried any F-11 tubes?

mharney · Post by **mharney** » Fri Jan 07, 2005 10:28 am

No I haven't. Just the F2's that I have now.

Kenny2428 · Post by **Kenny2428** » Fri Jan 07, 2005 10:29 am

Lol, whats up with that first pic?