346 flat head no start?

[Steve Passmore]

Bruce, you would need almost all the valves stuck to loose all vacuum at the carb. Did you read my post above about Oiling the bores?

[cadillac60]

Steve,  Thanks again for the info re the valves. Yes I did pay attention to your comments on squirting oil into the plug holes. I had done that a while ago but I must admit I put a very small amount in. I will try it  once again with the amount you mentioned. I have been using the High octane gas in the 38 ( in Canada Shell & Chevron have no additives in their High Octane). If, or should I say when I get the 48 running I will be switching over to the high Octane as well. I will try to get back to working on the 48 this week. Will keep you posted>

Regards

Bruce W

[cadillac60]

Steve,  I worked on the 48 this AM. I put 5 good squirts of oil in each plug hole  & turned it over as you suggested (with the plug still out). The compression on  the Left bank was close to 50PSI on each cylinder. The right bank did come up to 45-48 .  I then inserted the plugs but still will no start The car would run for a second then die. I took the plugs back out to make sure they weren't wet with oil & re installed them. The plugs were dry, I tried starting it several times & as I mentioned it would
start for about 2 seconds then die.

Regards

Bruce W

[Steve Passmore]

Well Bruce, that's a result, sort of!  The fact that the oil has raised the compression but nowhere near factory specs means you have a serious problem with the rings at least, I suggest they are completely worn out, a relatively easy job to replace but first  check your points to ensure the contacts are actually opening on every cam lobe. I have seen worn distributor shafts cause the number one position to open but several of the other lobes will not.  As you have now seen a couple of combustion's taking place I think she would go with a tow, not that it would help you much as it would need it every time. 
I don't honestly think your going to get a result with those compressions.   My 38 had compressions 50 to 70 PSI, it would start but was down on power, new rings produced 120 PSI and the difference was amazing. Good luck

[cadillac60]

Steve,  Thank you so much for your help, I have to admit I was hoping for an easy fix but my gut told me that never happens with old cars.

Thanks again

Bruce W

[Steve Passmore]

Art does have a valid point here Bruce but your first post stated the gas flow was good and I was assuming you had already done the fundamental first test for an engine that wont fire and that's remove the air cleaner, look down the carb venturi while you open the throttle and watch for the twin jets of fuel squirt down its throat from the pump jet??  Even if your main jets were blocked and you only had the accelerator pump all cylinders should run if you kept pumping it.

[cadillac60]

It might not have been the first thing we looked for but I have checked several times to make sure that the carb was getting fuel. When checking it seems to be operating normally.  I just can't believe my test on the compression showing so poorly. I am going to re do the oil squirting again & will use a different compression tester to make sure that it is correct. When I last drove the car I took it for a five mile run and was on a highway at 55 miles per hour for the last mile  & it ran very well. It was parked for 4 weeks and hasn't started since. As I mentioned before I knew the engine was somewhat tired but there was no sign of exhaust smoke only if I had coasted down a hill then stepped on it I would see some blue smoke.  I will follow up after my second compression test.

I apprerciate all the help, thank you,

Bruce W

[cadillac60]

Art,

I thank you for that heads up on the fuel system, as well as another compression test I will be checking the fuel lines as well as the fuel pump pressure and capacity. If all that fails I would then look at getting the carb rebuilt if that's what it takes.

regards

Bruce W

[Brett Baird]

Bruce,
The reason your engine will not start is that 50psi is not enough compression.  Realistically there are only three things that can cause that on all cylinders: 1) all of the valves failed at once when you shut off the engine - not likely; 2) all of the rings or cylinders are extremely worn - not likely or you would have left a smoke screen of James Bond proportions whenever the engine ran prior to the no start; 3) the timing chain slipped.  this is the most likely and actually happened to me with a 346.  I drove the car into the garage, shut it off and just like that - no start.  In spite of what some have surmised, there is plenty of room within the front cover for the chain to jump without hitting the cover.  I have overhauled several of these engines, and for what it is worth, you need a new chain and gear set.  Based on your description of blue smoke on acceleration, there is no doubt that there is some ring/cylinder wear and a complete overhaul is justified and undoubtedly the best choice, but if you just want to get the engine running, pull the front cover and put in a new chain and gears and restore proper valve timing.

[cadillac60]

I re did the compression test with a new Tester. I first squirted 4 good pumps from my oil can in each cylinder---- turned the engine over 4to 5 times and did the compression test as follows
cyl No 1 78 No 3 72 No 5 72 No 7 62 ----- Right bank-- No 2 70 No4 69 N0 6 70 No 8 72, this is far from perfect but is more in keeping with the 76,000 miles on the car.  I attempted to try to start  the car but would run for 1 0r 2 seconds and die. I tested the fuel pump pressure at cranking speed and it was 3lbs & held.  The pressure should be around 41/2 lbs but I don't think that should stop it from starting. I disconnected the lines between the pump & the Carb and it was clean with no particles of dirt showing up I have a filter between the tank and the pump which I checked & a couple of specs of sediment showed up.

Regards

Bruce W

[cadillac60]

I am also stumped, Steve has mentioned to check to make sure that the contacts in the distributor are all opening on each lobe. If anyone else has got any advice I would certainly welcome it!

Bruce W

[Bill Ingler #7799]

Bruce: Even though it looks from your compression reading that your engine needs rebuilding, it still should run, poorly but still run. You said it runs for a second or so and then stops. Sounds like fuel starvation. Since you have tried about everything, you might see if your carb has a plugged filter. Remove the inlet fuel fitting from the back of your carb( picture below) and check to see if you have a plugged filter. This filter can only be seen when the fitting is removed. This is a filter that was installed by the carb maker when it was new. If you have a filter and it is plugged then maybe that is your problem. If not then that is one theory that can be checked off.   Bill

[cadillac60]

Bill,

On my 48 the Carter carb has a fine screen filter which I have checked and it is clean, but you are correct when you talk about fuel starvation as that's what it feels like. If I look down the barrel of the carb & pump the throttle there is a nice spray of gas which looks normal to me. I thank you for your interest

Bruce W

[harry s]

While your checking fuel delivery try the pick up tube in the tank. You can disconnect the fuel line at the pump and blow toward the tank. You should be able to determine if there is a restriction and if not the tank will bubble. Sounds like it is totally frustrating to have checked most everything and still not able to start it. Good Luck.      Harry

[cadillac60]

I would like to thank everyone that had input into my no start problem-- after testing every idea it still not starting.


Regards

Bruce W

[Rod Dahlgren #19496]

stuck valves-- blame it on the EPA gas we have to use---

[Bob Hoffmann CLC#96]

Lots of good advice so far.
My suggestion... give it a good HOT start with a 12 volt jump.
And, maybe a little starting fluid. What do you have to lose at this point?
HTH, Bob

[cadillac60]

Art,  Thanks for your reply,  The timing chain has come up a few times.  Can it still be a problem with the timing chain if the #1 plug lines up with mark on the damper ( a/g) as well as the rotor lining up with no. 1 plug wire.

Regards

Bruce W

[Glen]

I had a similar problem with a ford flat bed with an inline 6.  One of the guys was using it for a while, fueled it up and continued to use for several hours before he shut it down.  The next day it would not start.  I checked everything.  After about a month of working on it on and off I was talking to the guy that used it.  He pointed out the barrel he fueled the truck from.  It was diesel.  He put diesel fuel in a gas truck.  It ran fine while it was hot, but would not fire a shot cold. 

Could there be some problem with the gas on Bruce’s car? 

[Tito Sobrinho]

Bruce:

I'm following this discussion for awhile. Electrical system, fuel system, chain out the sprocket etc. Seems to me that your carburetor does not allow air to continue the engine cycle after the initial start. The choke valve (flap) does not completely  close in a cold start and has to have a clearance.

I don't know what type of carburetor your car has but if is the Stromberg the clearance between the upper edge of the choke valve (flap) an inner wall of the air horn should be 11/64 of an inch.
If it is a Carter, the clearance should be 3/16 of an inch.
After the initial cold "crank", the pipe from the automatic choke will take care of opening the flap and make sure that this pipe is well connected to the exhaust manifold.
Check also the automatic choke for a weak spring, defective vacuum plunger etc.