larrywalk

One piece oil pan gaskets can be bought with a thin front seal also, and with right or left side dip stick holes. Check carefully before buying.

65air_coupe

One late reply followed by an even later one. Thanks for the offer. As for engine specs, I believe there are probably some numbers I don't readily have but here is what I do have:
406 cu in, 10.7:1 CR,
Edlebrock Performer intake with Demon 750 mechanical,
Hedman long tube headers,
Trick Flow Twisted Wedge Gen 1 heads, 64cc, 180cc intake runner
Cam is Comp XE280HR: Duration @ 0.050":230° / 236°
Max Lift w/ 1.5RR:.510" / .520" Lobe Separation:110° Intake Centerline: 106°

Let me know what else you need. You can email me at pdeinc01 at gmail dot com.

DucatiDon

Follow up:

I know its been a while. Have about a thousand miles on the engine now.
The oil leak turned out to not be the pan at all, but a misaligned timing cover gasket. Word to the wise in the future.

Car continues to run very strong, pulls well up to 7k.

Only current issues are a Vac Advance that doesn't appear to be pulling advance at idle, and some low speed trailer hitching.
The hitching is easily driven around by clutching at low speeds and keeping the RPM up over 2200 or so. Trying to smoothly accelerate below that is "uncomfortable", but easily avoidable. Accelerating from a stop, gets the rpms up quick enough that its not really an issue (even in 2nd gear), it only rears its head in slow stop and go traffic trying to be smooth.

Also After letting it sit for a length of time, it takes quite a while to warm up and smooth out enough to idle. Appears overly rich until warmed up. Once its been driven its OK. I thought this might be a high float issue, but doesn't appear related. What would cause it to run so rich after sitting? Just cold blooded? Too rich as it is, exacerbated by being cold and having sat? (I cant really call California "cold" by any means)

PS: I am now using a standard PCV valve setup. I have not touched the timing or advance yet....that and diving into the brakes are on tap for this summer. New exhaust system is in the works too. Waffling between the rams horns and headers.

claysmoker

What are all the numbers currently, idle without vacuum, idle with vacuum, mechanical, all in? And what rpm do all the numbers come in? I can't remember what you have for heads either, but then I can't remember to put my pants on some mornings and wonder all day why people are staring at me.

I had a trailer hitching issue with mine after the addition of the new engine, and it turned out to be too much total timing. Our engines are somewhat similar as I recall, though mine is a 406.

65air_coupe

Add mine to the mix of 383/406 motors that have lean surge issues. I have pretty much solved mine but took some time and learning...and instrumentation. I believe there's something about these motors that make them particularly sensitive to low rpm mixtures. My first problem is probably unique to my motor...a plug in the intake manifold was bottoming out without actually sealing. But fixing that only helped slightly. I disconnected my vacuum booster and vacuum advance without affecting the condition. Blocking the PCV did make a difference so I bought a handful and tested each one and was quite surprised to see how different they were. Well, how different one was from the others is more accurate. Most flowed about the same amount of air at idle which for my motor was too much. The most restrictive one gave me the best performance at low throttle and light load.

At this time I was running a Demon carb that did not have replaceable IAB or IFR jets so I drilled and tapped them to be able to make changes. The problem was I didn't have enough information, meaning data to quantify my changes. So I welded a bug into one the tailpipes just downstream of the end of the headers and installed a wide bank O2 sensor connected to a A/F gauge. I still struggled to discern jetting changes but finally got rid of my lean surge. I also found that both my old B27 vacuum can as well as a brand new one yielded more advance then specified. I slipped a sleeve over the pin to limit the travel and that's probably also helped with trailer hitching.

Hope this helps.

claysmoker

I have a little different tuning situation as I operate at 5K ft. I've had a QF 750 carb on it for a long time now, and it is squeezed down lean to work at this altitude. Luckily it has all the adjustments to get it to work here. The ignition setup is an MSD 8360 with a box. 24 degrees initial, 8 degrees mechanical, and 12 vacuum. It's happy at 44 total on 91 ethanol free. Compression is 11 to 1, AFR heads. I bought one of those Wagner adjustable PCV valves just for grins, and I am absolutely delighted with the way they work.

tbarb

Do you recall the IFR/IAB combo you are using in the carburetor. How much idle timing (initial & vacuum advance) are you running.

65air_coupe

If memory serves...and that's' questionable these days, I ended up going down 0.004" on the IAB and back to original size on the IFR which I can't remember what that was. Also it was a 650 Demon from my L79 327 and I have since replaced that with a QF 750 and haven't had to touch it's settings.

I'm back at 12* initial after running 10* for awhile and 12* seems to idle better with higher vacuum (17) .Total is 36*. I think that gives me 54* total with the 9* vac can. I didn't record the vac can readings but seem to remember I was getting 2-4* more advance than I should I was using a dial-back timing light which I don't trust completely but have timing marks on the damper and did confirm that I was getting too much. Now that I'm remembering all this, I just realized that part of my earlier lean surge could have been from having the wrong can on it for awhile. I started with the original can from the 327 (B27?) and then while I was chasing vacuum leaks, replaced it but somehow with an incorrect one that was dithering when the A/C kicked on an RPM dropped. I went back to my original can with a sleeve over the pin and all seems well now. I still intend to add an idle solenoid to keep the RPM from dropping too much with A/C and then I can crank down my normal idle below 1,000rpm.

tbarb

Thanks for posting that information, it really is a learning experience tuning these carburetors, with the camshaft specs you posted above I would think you can get that idle down a little more.

65air_coupe

Yes, it will idle nicely at 800 but when the A/C kicks on it's likely to stumble and die.

claysmoker

Try a little more initial timing and back off the others to get the same total. It will idle far better.