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Horrible burning smell on acceleration

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Old 02-25-07, 07:54 PM
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Soft & Wooly
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Horrible burning smell on acceleration

OK, so I have got my '79 running well enough to where I can actually go drive it. It's got a streetport pre-79 13B with dual Weber DCD carburetors and a header/collector exhaust. No emissions equipment of any kind.

Whenever I accelerate other than at very light throttle and low/medium RPM I get this horrible burning smell. It is not rich-fuel smell. It comes on anywhere over about 4500 RPM. I cannot really identify the smell. I know I don't want it.

I know this is not much to go on... mostly looking for ideas of what to look for.
Old 02-25-07, 11:37 PM
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I'm starting to suspect my alternator...
Old 02-28-07, 07:04 AM
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Is it an acrid smell that burns the nostrils? If so, put it in 4th gear and let out the clutch from a dead stop. If the engine revs, the clutch is burnt, if it dies, check the belt tensions, feel the alt to see if it's hot, check the alt bearing.

I'm in the process of installing a DCD setup on the widebody. Could you do me a favor and send me pics of the throttle and choke cable conections? PM for my e-mail addy.
Old 02-28-07, 08:04 AM
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Nah, it's not the clutch (RPM still in sync with speed), or the belts (first thing I checked). I got a new alternator but haven't put it on yet. I am pretty sure that is it though, as I think the alternator bearing is bad. If not that, who knows.

I... can't send you pics. I don't have a digital camera or camera phone. Maybe I can borrow one in which case I'll send you pics. It's pretty simple, though. There's a connecting rod that goes from the throttle linkage to a camshaft that is just bracketed there. The throttle cable loops over the cam to rotate the shaft which then pulls the connecting rods.

Camshafts, connecting rods, what is going on here?

What happened to your turbo swap? I'd rather have the turbo motor than the DCDs... I like them because they are period-appropriate but the turbo is really better.
Old 02-28-07, 09:50 AM
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Originally Posted by fluffysheap
There's a connecting rod that goes from the throttle linkage to a camshaft that is just bracketed there.
I suppose I should be more specific: the rod goes from the throttle lever on the carb to the camshaft.

As for the choke, of course the DCD isn't a real choke, it's a separate starting circuit, and it's not worth a hoot The ideal setup would be another camshaft style arrangement but what I actually have is a simple cable that splits and one end goes to the "choke" lever on each carb.
Old 03-01-07, 12:46 AM
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Yeah, the DCDs have a starter circuit like the Mikunis as opposed to an actual choke butterfly. I had the seller seperate the carbs from the intake for shipping and didn't get pics of it on the engine. I may have some coming from another member.

I have 2 cables going from the choke levers to a tube that the main choke cable attaches too. I not sure how to attach or tie down this tube, but I think the choke and cables will work even if the tube is loose.

TII project is still in the works, have many parts left to pickup before I rebuild the engine and begin the swap. I've been running a Mikuni 44PHH on the 12A-1/2bp and have known from the start it was too small. I'm installing and testing the DCDs to see what I can actually get out of the bp and how well I built the engine. Once the TII is in, the 12A goes up for sale, minus the DCDs, which will go on the future 13B build for the REPU.
Old 03-01-07, 01:17 AM
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My DCDs have their own little brackets for the choke cables. So, what I actually have is two cable sheaths coming from the one bigger cable conduit that each attach to the brackets on their carbs so you don't need a separate solid mount for the choke cable(s) anywhere. The joint between the conduit and the smaller sheaths is just sort of there. It's actually draped right over the main throttle linkage camshaft. The potential for the chokes to get out of sync is high with this setup (it depends on the way the individual cables are joined together rather than on a hard linkage) but as long as they both close fully it doesn't really matter much.

Starting performance is actually pretty good. I have been able to get it started in 40 degree weather without doing anything special. And I'm not ever likely to drive this car in any colder weather than that. Heck, in Seattle, it hardly ever even GETS colder than that.

Edit: If your other pics don't come through let me know and I will borrow a camera and take some.

Last edited by fluffysheap; 03-01-07 at 01:22 AM.
Old 03-02-07, 03:48 AM
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Thanks for the offer, still waiting on the other pics. If they don't show, I'll PM you.
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