preheater troubles

I've got two others, but this is far the best of the lot. The California smogged PICT/4 I only use for parts! The Kafer was a good carb before the EMPI 3417 exhaust. The third one is just a turd.

I tried a 55 idle jet, but wasn't happy with it. I'll try some others today.

I'll check that, thanks.

Yeah, has vac, but I need to make a harness for it today and find a replacement rotor before dropping it in.

By tight I mean the adjustment. Slack loosens as it warms. Too tight will disturb starting idle. Too loose will make it tick when warm.

Though, she idles great at first.

Reply to
David Gravereaux
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The Mexicans did that for a clearance purpose, check the link below and you will see the late Mr.Hoover mentioning it. It does not matter which of the two outlets the heat riser pipe ends in, it creates vacuum all the same.Unless I misunderstood what you wrote completely..

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J.

Reply to
P.J.Berg

On 12/08/2011 04:56 AM, P.J.Berg wrote: ...

Oh, that thread speaks volumes to me :) Why use electricity to make heat when all the heat I need *should* be coming up through the preheat tubes. Yes, this is exactly what I've noticed. My manifold is a whole lot colder now.

Last week when I drilled-out the heat risers cause EMPI ships them sealed for the dual carb folks, haha I didn't mention this before cause it solved nothing, I slipped on the right side and poke a hole.

The manifold heat was wonderful as there was a true flow through from right side to left side. The loud exhaust was terrible, but welded it shut to now have STILL a barely warm manifold.

Reply to
David Gravereaux

Options:

1) Make and weld a proper exit tube to go from the collector in the exhaust to the right side heat riser so I get best flow (and heating) possible.

2) A pair of Weber ICH carbs and the CB performance 3083 kit

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My 90amp flux core welder really isn't up to the task of cutting holes in a rather thick collector, nor do I have the raw material to start from... I'm just a backyard mechanic :/

I wanted to go to duals later on... new tire budget will go to carbs instead

Reply to
David Gravereaux

Done. Money spent. At least I'll have some boxes to wrap for under the tree.. To: Dave From: Santa

Reply to
David Gravereaux

In my Weber duals there is a disabled enriching circuit for the choke. I have read where sometimes an activation cylinder moves causing it to constantly flood. Anywho, those chokes are in there. Maybe you can get just the activating parts.

Reply to
John J Stafford

You will be blown away by the performance. Take care, however. You CAN over-rev a dual carb ACVW! (For the rest - you with single carbs have a restrictor - the carb itself.) :)

Reply to
John J Stafford

The venturi pipe is inside the muffler itself. There is only one. It slips over one end of the heat riser manifold to pull air through. At least that's how mine was in the '72.

Reply to
John J Stafford

Yup.

I know precisely what it looks like and how it works. The Mexicans just swapped them around so it would suck from the no.4 primary instead of no.2, basically just reversed the flow.

J.

Reply to
P.J.Berg

If you think this might be a problem, you can get rev limiting rotor arms

Reply to
tricky

If the engine has the original valve springs or others with the same spring rate the valves will float before you do any damage.

J.

Reply to
P.J.Berg

Got one and it does not work. Fortunately my engine is so well balanced that it soars to 8,000 RPM with no damage. I've had it to 9,000. The rev limiting rotor was set to 7,000. Not working. :(

Reply to
John J Stafford

Heavy duty double springs and zero-lash roller-rockers. This engine is really built. Too bad it has a very serious backfire. It's too darn cold to work on it now.

Reply to
John J Stafford

The IDF enrichment circuit is a bit different than the ICH which uses a real choke flap. Interesting story with IDFs... In my 2270cc T4 motor with dual 44-IDFs, I didn't have the enrichment mechanicals, just the block-off plate. Just two days on the motor, I did a 7000 rpm downshift into second gear coming off a highway exit ramp. I think that's what pulled the enrichment cylinder and wedged one in the up (open) position. It drove me nutts for a week trying to solve why the motor was running all unbalanced.

summary: blocking plates bad. Get the IDF choke mechanicals if only to make sure the enrichment "cylinders" don't get pulled up and wedged open on you.

Reply to
davygrvy

One of mine is partly up! So that's the wrong direction. I think I'll pull it down and pin it in place. Wow, it would be awesome if that were the only problem!

Reply to
John J Stafford

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