1967 Fairlane 390 do-over

[Cobrajet2]

I had the 390 in my Fairlane rebuilt by a local, reputable machine shop with parts
I had picked. I figured it to be a decent combination,  but something is not right with
This engine. Car launches well, but falls on its face. No power.  Really low vacuum, overheats in traffic and rarely makes it into the 14's ET wise.

[Drew Pojedinec]

To get some advice, as many details as possible would be great.

First question would be some engine specs, head specs, camshaft, and timing.

[Cobrajet2]

Yeah, sorry. I was trying to ad some video from my phone, but it would'nt take. Too big a file maybe.  So, me and a friend are going to do some checks and post the findings here. Something to do over the long Winter.  More to come.

Mike

[My427stang]

A parts list, with gearing and tranny would be a great start.

A couple of quick observations though, a 390 running high 14s isn't horrible, in fact it's pretty good with stock exhaust manifolds. 

I'd be looking at making 100% sure I was getting full throttle, the timing curve was right, and my balancer was checked to be indicating timing marks correctly. 

Also, the distributor looks to be either in a retarded position or dropped in a tooth off (a tooth off is fine, but just an observation), but it looks like #1 wire is moved 2 spots over, but the distributor isn't turned all that much.  Hard to tell from a picture, but incorrect timing and a stock distributor could rob it blind

Additionally, overheating could come from both retarded timing (which also contributes to low vacuum) and a bad fan/pulley combo.

As Drew pointed out, the more you list of parts and setup the better.

[Drew Pojedinec]

Additionally, overheating could come from both retarded timing (which also contributes to low vacuum) and a bad fan/pulley combo.

My initial thought as well.
Can't tell how many people send me a carb and I check it out, test it, etc and find nothing wrong.  I then start asking about timing and they either don't know, or it's like 6 degrees btdc  lol.

[Heo]

My first thought, timing or some restriction in the exhaust

[Barry_R]

I will "third" the retarded timing thoughts - symptoms sure fit.

[67428GT500]

Do people on the forum really run into dampers that the ring has shifted that often? I know my custom grind was straight up, but it seems many cam manufacturers grind in a 4 degree retard.
                                                                                                    -Keith

[Heo]

I happened to me a few times. the last one i saw
slipped real bad. Was on a 392 Hemi in a bucket-t
I happened to walk by it on a gas station when he
started it. I saw the ring slip of the damper towards
the block and started to flop around
I bet he thought i lost it when i started to  yell at him to
kill the engine
My current FE had several new 0 marks made with a chisel
One FE i had was missing the ring completely
A friend had a real hot 327 chevy, i was riding with him and
he wound it out in second and the ring exploded
So i always buy a new damper

[RustyCrankshaft]

Same here. Seen lots of bonded dampers fail/slip on any brand engine and common on FE's. I have one on a 360 I pulled that had slipped probably 30* or more. I bought the truck cheap because they couldn't get it to run. I cranked about 45* more timing in it and drove it home.

[FirstEliminator]

The 351c in my 70 Cougar lost the rubber on the damper. The ring was just floating on hub. It happened earlier in the day and this evening was a big Friday night cruise-in. When I would shut off the engine the ring would spin down then clank-clank-clank before it stopped. I said to my friends to guess what the noise was. They came up with some crazy ideas like a main cap falling off. It was pretty funny for a while.

   If the balancer is in question it would be a good idea to use a piston stop to verify it's accuracy.

   I had a truck in my shop a while back that the guy just spent about 10 G's on a 347 stroked 302. The timing was really off. It would idle, then total timing was o-k. The drivability was lousy, performance was sluggish and it liked to stall. Here is why: They had the vacuum advance hooked up to full time manifold vacuum. This vacuum can had 20 degrees of pull. Now, it's fine to hook the advance to manifold, but not when you set the initial timing at 10 BTC. Cause when you give it some throttle it goes to 10 degrees ATC.  So his total timing was way low at mid throttle to wide open. I took vacuum out of the equation, set the initial and total. Then adjusted the vacuum to only pull about 10-11 degrees----on top off proper mechanical timing and the truck drove great. 
     If you have vacuum hooked up, disconnect it and get the mechanical set up first.

[Katz427]

My cousin had a 390 rebuilt by a local rebuider for his galaxie. Engine always acted "lazy" timing changes didn't help much. I thought it was off a tooth on timing gear. Turned out the rear cam tunnel plug was installed backwards. Enough drag that it wore out the timing chain in 150 miles. After the fix, engine ran fine, good power. Of course the fix was to remove the engine and fix the problem along with the head gaskets on backwards.

[Cobrajet2]

My low vacuum woes at temperature.

[Cobrajet2]

As many of you mentioned, I looked at the to see if something was goofy with the balancer and the timing marks, but I think it is pretty close. The balancer is an original, but the rubber feels uniform the whole way around. Not sure if when a balancer slips if it stays slipped or moves around with rpm. I did not put a light on it today as I wanted to check compression today.

Not sure why my pictures show up 90 degrees out, other than maybe it is my phone. Sorry for that!

[fekbmax]

Still be a good idea to get the parts and combo list so it could be looked over

[Cobrajet2]

So, today I braved the cold and messed around in the garage checking some stuff on the Fairlane. Compression and leak down.  Testing showed I had 2 weak cylinders on leak down. #5 at 17% and #7 at 18% after a little oil in #7. That cylinder was 22% at first.

Compression-wise 7 of the 8 cylinders ranged from 151 to 162. The one weak cylinder was #8 at 140.  This motor had no issues during break-in and probably has less than 1000 miles on it.

cyl.    comp.    leak-down
1        155       8%
2        160      11%
3        157      11%
4        156      10%
5        162      17%
6        160      8%
7        151      18%
8        140      13%


Motor is a .030 over 390 with C8OE N Cobra Jet heads.
Cobra jet exhaust manifolds
Comp XE 274 cam kit. Lifters, springs and hardware all matching. Ford adjustable rockers.
Pistons are Silvolites (I think)! maybe part# 1130, but not sure. Cannot find the old box. 
PI intake with a Holley, Ford distributor with a Pertronix.

[RJP]

Your minor compression variation numbers are not your problem. Your worse leak-down [17-18%] can be considered normal for a fresh, unbroke-in engine. If it were mine I'd put the timing light down for now and just crank some advance into the distributor while the engine is running and see how the engine responds. I'd bet the engine would smooth out, vacuum would come up, water temp would drop and you'd gain some, or maybe a bunch of low end response. Do NOT leave the timing as is if this helps. Now hook up the timing light and see where the timing is. If the timing light indicates an over advanced initial timing @ idle [and at say 3000 rpms] look for the timing pointer and dampener marks to be off and correct as needed. Don't use "book" timing specs as you'll need to experiment with a timing curve that works for your engine. Stick with some safe guide-lines here...Try 12-16 deg advanced @ idle, 34-36 [centrifugal] at 2800-3200 rpm then if you are using a vacuum advance adjust as needed for good drive-ability with no pinging or detonation. 

[Heo]

I se you have around 7 in vaccum! I have a 282 S cam single plane intake
ported heads and i have 11 in vaccum so something wrong there i think

[Cobrajet2]

I was back out in the garage today messing with the Fairlane. First, I had to go thru and clean torpedo heater as it suffered flame out shortly after start up. Got it going and got some heat.

As recommended, I put a timing light on it after warming it up. Light was only reading 5 degrees initial. Put some advance in the timing to where it smoothed out a little and sound good by ear.  Put the light back on and it read 23 degrees idling. Goosed It up to +or- 3k rpm and light read 50 degrees. Vacuum improved a little.

I made up a piston stop out of a spark plug non fouled and will check TDC next. I think I can fit the 18 inch Moroso degree with the motor in the car.

I also releaked cylinders 5 and 7, and got better numbers than before. I guess because the motor was still warm this time. The plot thickens.

[Cobrajet2]

Have the heads off now. Lots of crud and
contamination for less than 1000 miles.

I was able to verify that there was no slippage in my balancer. Bought a degree wheel and it checked good.  I wanted to see what piston was used because I could not remember the part number I supplied, so off came the heads.

[Cobrajet2]

The cylinder walls don't seem to have that nice dull-gray crosshatch look to them either. Hard to tell from the pic, but the walls are shiny with fine scratches all seeming to go one way instead of a crosshatch pattern. Guessing it will have to come all the way apart now, unless we find something really wrong in the heads, which were re-done, although a long time ago.

[My427stang]

So first, I would say with a piston .020 or so down the hole, and the heads you run, assuming an 8554 head gasket, you just have low static compression for the cam.  Depending on how much your heads and block were cut, and using the blue gasket, you could be at 9:1 for a cam that would prefer 9.75-10:1 in a 390, add the 60 degrees of overlap and you lose bottom end

Low compression and overlap will also show itself as low vacuum as well, even worse if timing is late.

Those cylinders don't look bad to me, it will be interesting to see what the heads do, but I don't expect much wrong. 

So you could just advance the heck out of the cam, but if you advance that cam, assuming you advanced it to 102, you'd gain some torque, however that piston likely doesn't have a lot of room for the intake valve. You would have to measure clearances, both lift and radial (especially radial)

I see three courses of action after you determine if the valve job is good, and they  apply even if you find something in the heads.

1 - Put it back together, crank up the initial to about 16, recurve the distributor like RJP said. "Tune it option"

2 - Put it back together, checking valve clearance and advance the cam 2-4 degrees and recurve the distributor like RJP said.  "Drive up low end power and tune it option"

3 - Rebuild it to modern specs, (leave the cam at 106, .045 or so quench, lots of room for valves, forged pistons, modern ring set, cc the heads, deck it to make sure it's straight, and get at least a 1/2 point of compression more up to about 9.9:1, and then recurve to something like 12-14 initial, 36 total all in by 2800.  "The best option if budget allows"

The thing I'd like to point out though, is the heat is likely only related to performance if your ignition timing is retarded.  If it is not late, then it is a likely separate issue, and likely more related to the fan you run. 

Again though, I'd really look close at ignition timing, we know you are low compression for the cam, so it won't ever be low end torquer without changes, but the combination of heat and low vacuum indicate ignition timing issue.

If that is not the case, then I would add compression or advance the cam, and then go find why it runs hot

[Cobrajet2]

Thanks for the response, Ross. You are correct on the 8554 head gasket. A friend is going to help me check out the heads, and I hope there is something there to explain the oil contamination, rather than the rings. Still more investigating to come and I'll post.

Thanks,
Mike

[57 lima bean]

When doing a leakage test I've always removed (don't just loosen) the rocker shafts.This will eliminate any potential of a valve being open.