LilJayV10

iTrader: (5)

I was reading heavy chevy's thread and there is a lot of good info in there. I had a few questions concering my setup. All of the spark plugs are burning clean but they have a brownish tint to them. the car smells like its running rich and smokes at WOT, but its not blue smoke that went away when #5 cylinders rings finally decided to seat. It's a black/greyish smoke and smells really bad but none of the plugs are fouled or show any signs of it. It drives me nuts. I know I have a tranny leak and am burning some transfluid but thats not much(its either the front seal or the convertor leaking, dont know which yet.)

also, I was messing with the timing tonight, intial is 12 degrees, total I don't know because the good timing light is at work, I will find that out later this week. The vacuum advance doesn't make a difference in timing, when you rev it up it doesn't add any more timing than without it. When I was at the track and had race gas in it I bumped the timing up to 16 inital and picked up 1.2 mph and started running 7's
750DP
jets 74/81
squirters 28/31
cams, pink/blue, I think, the carb is dirty I couldnt tell and didn't feel like taking it apart tonight

the distributer is stock HEI with medium springs in it, stock weights, MSD 6AL w/ HEI conversion R44T AC plugs

one more thing, when I check the timing at idle the timing light works fine, when I speed it up, 2500-3000, the timing mark on the balancer moves(obviously to show increase in timing)but it starts bouncing around, almost back to 12 degrees and the light flickers. Is this the timing light or is something else going on? It only does it at higher RPMs but the engine isn't missing or surging.

thanks for any replys

406 10:1compression
220cc iron protoplines 2.05/1.60
roller cam, 288/294 236/242 .540/.580 lift 110LSA
holley steet dominator intake, ported
9.5 ACT 2800 stall(stalls between 2800-3000)
3.23 gears
long tubes w/ dual exhaust

car has ran the best of 7.82@90.4 w/1.89 60ft on radial tires, no SFC's, LCA's or relocation brackets.

With some suspension mods, a little more gear and tuning I hope to be mid 7's on these tires. Theres gotta be more in there!!! Somewhere!!!

Chickenman35

Brown tint likely a fuel additive in un-leaded fuel. Do you run a cat? Bad smell could be from catalytic convertor. Jetting looks about right . I ran a similiar combo in my car.

Smoking at WOT is likely a combo of the pink cam and #28 shooter in the Primaries. Try a Blue Cam in #2 hole and a #31 shooter. Car will probaly launch harder and Black smoke should disappear.

Sounds like the Vacuum advance is pooched. I'd suggest getting a Crane Unit and connecting to Manifold Vacuum. Wind the tension out all the way for the way on the Crane Vacuum can. In or out I can't remember. Read the instruction. Whatever gives the " least " tension on the diaphram. Car should launch harder. Reduced times with static sadvanced to 16 degree shows that the car wants more intial lead. That's the whole idea of running Manifold Vacuum. More torque on the bottom end for launch, without exceeding correct mechanical advance curve when RPM comes up.

Total advance ( mechanical and static )with vacuum disconnected should be in the 36 to 38 deg range. Try to have it all in by 3,200 to 3,500 rpm. May be tough getting that with an HEI distribitor. Make sure that mechanical advance does not start below 1,000 rpm or whatever your minimal idle speed is. You may have to punch the initial up to 16 deg as you've discovered to get 36 to 38 total. You need the good gas as you well know.

Beware of aftermarket weight and spring kits such as Moroso and MR. Gskt. Most of them are crap. Can actually give less mechanical advance than re-worked stock cam and weights. Lousy profiles on the advance cam.

Most HEI's only put out around 16 to 18 deg mechanical advance. Best advance cam to get is an early Caddy unit...73 through 75. About the maximum mechanical advance curve that GM ever put out. 22 degrees. Check the bone yards.

Pony Killer

hey there jay here's my take on the whole thing..
first thing that popped out to me are the spark plugs.

if protoplines are like vortecs... as in.. take the same sparkplugs.. those are the wrong plugs. factory plugs are the LTS' gm lettering for long shank tapered seat, extended tip. if it needs them.. and you are running the R44 t's... the end of the spark plug is barely sticking out of the hole. I run R 42 LTS in mine if i remember.. or 43's. gapped at .035
At the track take the vac addy off. the crane setup like they are suggesting is nice.
if you are looking to give the hei a shot.. i put a pertronix flamethrower rebuild on my stock hei.. and just run that.. works great till near 7K.

i use the vac addy hooked up to manifold vacuum to smooth out the idle and make it more driveable.

I run about 36* of total timing. hard to tell the initial since the springs are the lightest ones and starting to advance.. but the motor loves it. bottom line is... i run nearly fixed timing when it comes down to it... it's all in when the conververter flashes off the line at 34-3500 and it stays there the rest of the run.
Which is not that uncommon running fixed timing on reasonably stout or better smallblocks.

for kicks try timing it like mine.

as for the pump cams and squirters.. mines not really a great example to go off of since i run a vac sec carb..

But your running a lot of power in a reasonably light car..
put bigger squirters in and see if the black smoke down the track goes away.. what they'll do is make the pump shot more intense but last not as long..
on my vac sec i'm running the dark green pump cam and a 35 squirter.
gonna need more gear too ;-)

your gonna have to play around and get the timing right before you can get the jetting right..

once the timings there.. the jetting gets easy.

F-BIRD'88

The smoke at WOT suggests a ignition problem.
Or you could be sucking oil up thru the valve cover into the PCV.

(valve cover pcv baffle) Install a inline paper element fuel filter in the pcv line going to the base of the carb. this will trap the oil if that the problem.
Or fix the valve covers.

Check the usual suspects on the secondary side.

the timing light problem is also an indicator of this.

Spark scatter possibily , check the cap and rotor.

Could just be the timing light can't handle the strong spark of the
MSD.

You may need to recurve your distributor to get the timing curve you need.

More initial, a moderatly fast curve increasing to 34/36 deg will probabily work the best.

Sounds like your vacuum advance diaphram is no longer working.

You will probabily need about 14/16 initial and 36 total with the setup you have. Use ported vacuum. the right amount will be found by experimentation. about 15 to 20deg usually.

Try a set of R42ts plugs for raceing. A little cooler.

LilJayV10

iTrader: (5)

I haven't had any time at all to work on the car. I am going to try and get it to the track one more time on saturday and mess with it.

The iron protopline heads use the short reach plugs, the aluminum heads use the long reach. Protopline recomends a C59C or V59C(can't remember which part number is the short one at the moment) That crosses to a autolite racing plug, a 123 I think, the guy at the parts store said thats an extremely cold plug used in alcohol engines and I should go with a hotter plug. so i went with a 125,(its been a while)The plugs never cleaned up, so I got the dimensions from the spark plug boots and crossed them to a AC plug that I actually know something about. I went with the 43t or 44T(heck I can't even remember what I put in now)and they burn really well.

Something about the autolite plugs, the rings hadn't seated all the way when they were in and was burning alot of oil and I didn't have the MSD on at the time. #5 still would oil foul the plug because of the rings, then one day it finally sealed and no problems since.

Its late, I'm headed to bed.
Jason

LilJayV10

iTrader: (5)

one more question. at the track this weekend, since I don't have my ignition curve tweaked, whats wrong with speeding the engine up so it has full mechanical advance, then advance the distributer till it has 34/35 degrees total and run it like that. I know that the initial is probably going to be high but will it hurt anything? I just want to see how fast it will go with more total timing

Chickenman35

Nothing wrong with that. In fact it's an essential.

Run the engine up to around 3,000 to 3,500 rpm. Check the Total advance ( Vacuum advance disconnected ). You want everything in by about 3,000to 3,500 rpm.

Then run it to 4,000 to see if it advances any more. If it does advance more then you need a tad lighter spring or a bit heavier weights. Also check to see if the timing mark holds steady at 4,000+ rpm or bounces. Can be caused by running too light of a spring and weight.

Problem is to balance the total advance rate and still have the distributor weights close all the way at idle.

I prefer a heavier weight with a bit stronger spring. Ensures that the mechanical advance returns to zero at idle and I find that the extra mass of the weights stabilises things at high rpm resulting in less Spark Scatter.

LilJayV10

iTrader: (5)

Aren't HEI distributers limted by the total advance they can actually give, isn't is 15 degrees or so? I have read to get more mechanical advance out of it to take a small file and make the slots longer so there is more travel? Is that right? I have seen the HEI kits at the auto parts stores with new weights and different color springs. I have the medium springs in there now, I had the light springs in but they weren't strong enough at idle. This was on my 350 though and not the 406. I am still kinda in the dark about how to tune the iginition curve.

Chickenman35

Yep....HEI Curves are limited by total mechnaical advance. That's why they put such a honking big vacuum advance can ( 20 deg the norm ) on them.

You can get 16 to 18 degrees out of an HEI with the stock cam and weights...depending on the year and model of the car. The lenght of the slots is not the limiting factor...it is the profile of the cam that has the most influence. Most of the Aftermarket HEI kits are absolute crap. Can have less total advance than a good stock profile.

As noted...Early Caddy HEI's had one of the best cam and weight profiles. You can get 20 degrees out of these...sometimes 22 deg. Some early trucks can also have big curves. " Good " cam profiles from GM are usually thick on the arm side with a distinct ramp. The other side will be noticably thinner and flatter.

Search the boneyards for early HEI distribitors. Start popping the cams and weights off them.... and Ahemmm..... pop them in your pocket or somewhere....:lala:


Researching General Car repair Manuals, such as MotorBooks or Chiltons can give usfull info. Included are mechnical advance specs, vacuum advance specs and distributor numbers for different makes and models. Once you have this info you may even find that you can still get the necessary weight and cam pkg from GM.

LilJayV10

iTrader: (5)

I have been reading a lot of f-birds and chickenman's threads and instead of asking all sorts of questions in other threads, I will bring mine back. To be honest, I don't even remember posting half the stuff, it's been a while.