The Ford Barn

Dave in Denver · 10-10-2012, 11:27 AM

My 15 year old son and I were on a troubleshooting drive yesterday in our the '31 CCPU we have been rebuilding over the past couple of years. The rebuilt engine was finally sounding good, the timing seemed to be on. Then after making a few stops and then beginning to head home, we started to climb a small hill, shifted from 3rd to 2nd over (I have a mitchell overdrive unit in the truck) and about half way up the hill the truck back fired and stopped like it had run out of gas. I quickly checked the gas valve (I have left it closed before), it was open. tried to quickly restart the truck as I shifted to neutral, the engine turned over but would not start. We coasted to the side of the road. When we stopped some troubleshooting began.
- No leaks to be seen (oil, water or gas)
- the fuel pump was running and delivering gas to the weber 32/36 dgv carb
- all the plug wires and coil wire were attached
- nothing looked loose.

I had him press on the starter rod, the engine turned over but would not start.

So , we pushed the truck the 1-1/2 miles back to the house.

Once back in the garage, I did a compression check, the results were 0, 0, 0, 0 or more like 30 then leak down to 0 on all four cylinders.

The engine is a Riley Two Port, inserted, pressurized Model A Ford engine. I took off the valve covers and the rockers went up and down as the engine was rotated by hand.

My first guess is a blown head gasket. But before I lift the almost 100# head off the block I want to ask you for some advice.

Specs: '31 CCPU
Riley Two Port, inserted, pressurized Model A Ford Engine
Petronix distributor
Weber 32/36 DGV carb

Thanks,

Dave

Bob C · 10-10-2012, 01:04 PM

Not very likely a blown head gasket would leave you with 0 in all four cylinders. I would
do a leak down test to see where the compression is going. Did you check for spark
before you started pushing it?

Bob

zzlegend · 10-10-2012, 01:13 PM

Cam gear?

MikeK · 10-10-2012, 07:24 PM

Is this the first time you had it up to full operating temp? If it is a Yapp/R2P I would look at the lock adjustment on those long intake pushrods. Of course, a leakdown test as Bob C has suggested would narrow down what to look for. Hopefully you are using a metal cam gear. Way too much load with an OHV for a fiber gear. zzlegend may be on target.

Dave in Denver · 10-10-2012, 08:15 PM

More info but not closer to solution:

- checked upper RIley valve train and all is moving clearances are
still where the were when I set then a few months ago
- checked timing gear, it rotates as i turn the engine over by hand
- took off the side cover and all of the block valves go up and down.
- it has been up to operarting temp about 10 times over the past few
months, a few drives around the block, this was the first time more
than a mile from the house.
- checked compression again and it is 30# in cylinder 1 and 0# in the
other four.
- before this episode I was seeing about 105# per cylinder compression
- looking through spark plug holes with a flashlight, I can see the pistons
go up and down
- the timing gears were aluminum when the engine was assembled. I
agree that the 7:1 riley is too much for fiber gears
- placed long Qtips down spark plug holes and did not pick up any water
or antifreeze so I believe the water system is still sealing
- the oil is at the same level as before this episode, and i don't see any
water in it
- I am at a real loss as to why I have no compession

Before I pull the Riley head I am going to do some more thinking.

Thanks, Dave

zzlegend · 10-10-2012, 08:34 PM

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Reason i said cam gear was that it sounds like the valve train is out of time with the piston movement. Like the gear skipped a few teeth. Just my thought. Maybe other engine guys will chime in.

Vicky · 10-10-2012, 08:42 PM

Long shot, but maybe the exhaust valves are the problem? If they are larger valves, they may hang on the head gasket as it goes around the single valve. Hard to believe all four would be a problem at the same time. Can you see the valves thru plug holes, or maybe exhaust ports?

You may be able to take the exhaust manifold/header off, as as the engine is turned over, every time the piston comes up it would force air out the exhaust (if the exhaust valves are hung open or not correctly adjusted).

Also, after I thought about it, the rockers push two valves. I know that getting both valves with the same clearance can be a problem. Maybe one of the intake valves is not seating correctly?

If the rockers have the felt in the top, the felt could interfere with the rocker (and valve) returning to the home position. Maybe remove the felt and give it a try.

Sorry I can't be more help. Just some thoughts.

CarlG · 10-11-2012, 10:05 AM

Quote:

Originally Posted by Dave in Denver

...checked compression again and it is 30# in cylinder 1 and 0# in the other four...

That must be some conversion -- OHV & 5 Cylinders!

1928Pickuppain · 10-11-2012, 10:11 AM

Heres one id take a look at that would explain it you have gotten the motor up to operating temp a few times now and the metal will have expanded and contracted a few times. Metal never truly goes back to it's origional size once it's been expanded a few times maybe when you did your valves the first time they were just seating now that Thebes expanded contracted there no longer seated at all and may be letting the air pass by them ( this happens to me recently on a 83 iron head I built for my brother) try resetting the valves. Also before you do that rotate your engein while you watch the valve train rise and fall untill you get cylinder no.1 to it's compression strok (both valves "should" be seated at this point) then put it in gear with the ebrake on and hook your compression tester end up to your compressor presurize the cylender with 100 psi down into the plug and listen to were it's coming out wether it's coming from the valves, around the head gasket, or blowing past te rings and out of the vent tubes this is a good way to diagnose were to start.

Bob C · 10-11-2012, 11:08 AM

Can the valves hit the pistons if there is a problem with the cam gear?

Bob

Dave in Denver · 10-11-2012, 11:45 AM

Thank you for the suggestions so far. This morning I jumped in a did the work to take the Riley Two Port head off the engine to see what is happening inside the engine. Well after the head was off and placed on the bench the issue was found. When I assembled the engine I did not follow Charlie Yapp's advice and place fire wires between cylinder 1-1 & 3-4 in the narrow area on the block. I figures I had a good gasket and did not need them. Well what I found was a blow out of the composite gasket between 1-2 & 3-4. This explains the loss of compression in all four cylinders during checking and also during the leakdown test. I would try to pressurize one cylinder only to have it leak out the adjacent cylinder. Oh my.

Now during assembly I will place fire wires into between the cylinders as the head is reinstalled on the block.

I guess climbing the hill a few days ago made the engine work a bit more than sitting in the garage and blewout the gasket.

I have much empathy for Marshall V Daut, during his cross country drive a few years ago in his A400 with a Riley Two Port that blew a gasket on the side of a deserrted road. I was only 1-1/2 miles from home though.

Just when I think I have it all figured out, these Model A's throw me a curve ball.

zzlegend · 10-11-2012, 01:59 PM

Well hope fully you found the problem Dave. Good luck with it and keep us updated.

bykerlad · 10-11-2012, 02:15 PM

Can I ask what is a fire wire .?

Dave in Denver · 10-11-2012, 04:06 PM

fire wire as I have been told is a .060 length of steel wire placed on the block under the gasket between cylinders 1-2 & 3-4 to help prevent gasket blowout in this area.

columbiA · 10-11-2012, 10:58 PM

Years ago I installed an original early 2- port Riley-with the spark plugs on RH side-and put well over 75,000 miles on it I just used the standard 2-port copper asbestos gasket and it never blew.Oiling the rockers was done by squirting oil thru two holes in each valve cover with 1/2 a felt insole under the covers.I have heard of a few people having trouble with the repro heads blowing gaskets.

Rich in Tucson · 10-11-2012, 11:15 PM

"Just when I think I have it all figured out, these Model A's throw me a curve ball."

The Model A had nothing to do with throwing a curve ball, you are in a totally different sport with a what you are running.

And I wish you complete success, it will be fun when you get there!

10-10-2012, 11:27 AM	#1
Dave in Denver Member Join Date: May 2010 Posts: 67	Unexpected Exercise My 15 year old son and I were on a troubleshooting drive yesterday in our the '31 CCPU we have been rebuilding over the past couple of years. The rebuilt engine was finally sounding good, the timing seemed to be on. Then after making a few stops and then beginning to head home, we started to climb a small hill, shifted from 3rd to 2nd over (I have a mitchell overdrive unit in the truck) and about half way up the hill the truck back fired and stopped like it had run out of gas. I quickly checked the gas valve (I have left it closed before), it was open. tried to quickly restart the truck as I shifted to neutral, the engine turned over but would not start. We coasted to the side of the road. When we stopped some troubleshooting began. - No leaks to be seen (oil, water or gas) - the fuel pump was running and delivering gas to the weber 32/36 dgv carb - all the plug wires and coil wire were attached - nothing looked loose. I had him press on the starter rod, the engine turned over but would not start. So , we pushed the truck the 1-1/2 miles back to the house. Once back in the garage, I did a compression check, the results were 0, 0, 0, 0 or more like 30 then leak down to 0 on all four cylinders. The engine is a Riley Two Port, inserted, pressurized Model A Ford engine. I took off the valve covers and the rockers went up and down as the engine was rotated by hand. My first guess is a blown head gasket. But before I lift the almost 100# head off the block I want to ask you for some advice. Specs: '31 CCPU Riley Two Port, inserted, pressurized Model A Ford Engine Petronix distributor Weber 32/36 DGV carb Thanks, Dave

10-10-2012, 01:04 PM	#2
Bob C Senior Member Join Date: May 2010 Location: So Cal Posts: 8,767	Re: Unexpected Exercise Not very likely a blown head gasket would leave you with 0 in all four cylinders. I would do a leak down test to see where the compression is going. Did you check for spark before you started pushing it? Bob

10-10-2012, 01:13 PM	#3
zzlegend Senior Member Join Date: May 2010 Location: Reseda, Calif. Posts: 2,188	Re: Unexpected Exercise Cam gear?

10-10-2012, 07:24 PM	#4
MikeK Senior Member Join Date: May 2010 Location: Windy City Posts: 2,919	Re: Unexpected Exercise Is this the first time you had it up to full operating temp? If it is a Yapp/R2P I would look at the lock adjustment on those long intake pushrods. Of course, a leakdown test as Bob C has suggested would narrow down what to look for. Hopefully you are using a metal cam gear. Way too much load with an OHV for a fiber gear. zzlegend may be on target.

10-10-2012, 08:15 PM	#5
Dave in Denver Member Join Date: May 2010 Posts: 67	Re: Unexpected Exercise - more info More info but not closer to solution: - checked upper RIley valve train and all is moving clearances are still where the were when I set then a few months ago - checked timing gear, it rotates as i turn the engine over by hand - took off the side cover and all of the block valves go up and down. - it has been up to operarting temp about 10 times over the past few months, a few drives around the block, this was the first time more than a mile from the house. - checked compression again and it is 30# in cylinder 1 and 0# in the other four. - before this episode I was seeing about 105# per cylinder compression - looking through spark plug holes with a flashlight, I can see the pistons go up and down - the timing gears were aluminum when the engine was assembled. I agree that the 7:1 riley is too much for fiber gears - placed long Qtips down spark plug holes and did not pick up any water or antifreeze so I believe the water system is still sealing - the oil is at the same level as before this episode, and i don't see any water in it - I am at a real loss as to why I have no compession Before I pull the Riley head I am going to do some more thinking. Thanks, Dave

10-10-2012, 08:34 PM	#6
zzlegend Senior Member Join Date: May 2010 Location: Reseda, Calif. Posts: 2,188	Re: Unexpected Exercise Sponsored Links (Register now to hide all advertisements) Reason i said cam gear was that it sounds like the valve train is out of time with the piston movement. Like the gear skipped a few teeth. Just my thought. Maybe other engine guys will chime in.

10-10-2012, 08:42 PM	#7
Vicky Senior Member Join Date: May 2010 Location: Colorado Posts: 235	Re: Unexpected Exercise Long shot, but maybe the exhaust valves are the problem? If they are larger valves, they may hang on the head gasket as it goes around the single valve. Hard to believe all four would be a problem at the same time. Can you see the valves thru plug holes, or maybe exhaust ports? You may be able to take the exhaust manifold/header off, as as the engine is turned over, every time the piston comes up it would force air out the exhaust (if the exhaust valves are hung open or not correctly adjusted). Also, after I thought about it, the rockers push two valves. I know that getting both valves with the same clearance can be a problem. Maybe one of the intake valves is not seating correctly? If the rockers have the felt in the top, the felt could interfere with the rocker (and valve) returning to the home position. Maybe remove the felt and give it a try. Sorry I can't be more help. Just some thoughts.

10-11-2012, 10:11 AM	#9
1928Pickuppain Senior Member Join Date: May 2010 Location: Billerica, Ma Posts: 461	Re: Unexpected Exercise Heres one id take a look at that would explain it you have gotten the motor up to operating temp a few times now and the metal will have expanded and contracted a few times. Metal never truly goes back to it's origional size once it's been expanded a few times maybe when you did your valves the first time they were just seating now that Thebes expanded contracted there no longer seated at all and may be letting the air pass by them ( this happens to me recently on a 83 iron head I built for my brother) try resetting the valves. Also before you do that rotate your engein while you watch the valve train rise and fall untill you get cylinder no.1 to it's compression strok (both valves "should" be seated at this point) then put it in gear with the ebrake on and hook your compression tester end up to your compressor presurize the cylender with 100 psi down into the plug and listen to were it's coming out wether it's coming from the valves, around the head gasket, or blowing past te rings and out of the vent tubes this is a good way to diagnose were to start.

10-11-2012, 11:08 AM	#10
Bob C Senior Member Join Date: May 2010 Location: So Cal Posts: 8,767	Re: Unexpected Exercise Can the valves hit the pistons if there is a problem with the cam gear? Bob

10-11-2012, 11:45 AM	#11
Dave in Denver Member Join Date: May 2010 Posts: 67	Re: Unexpected Exercise - problem found now work begins Thank you for the suggestions so far. This morning I jumped in a did the work to take the Riley Two Port head off the engine to see what is happening inside the engine. Well after the head was off and placed on the bench the issue was found. When I assembled the engine I did not follow Charlie Yapp's advice and place fire wires between cylinder 1-1 & 3-4 in the narrow area on the block. I figures I had a good gasket and did not need them. Well what I found was a blow out of the composite gasket between 1-2 & 3-4. This explains the loss of compression in all four cylinders during checking and also during the leakdown test. I would try to pressurize one cylinder only to have it leak out the adjacent cylinder. Oh my. Now during assembly I will place fire wires into between the cylinders as the head is reinstalled on the block. I guess climbing the hill a few days ago made the engine work a bit more than sitting in the garage and blewout the gasket. I have much empathy for Marshall V Daut, during his cross country drive a few years ago in his A400 with a Riley Two Port that blew a gasket on the side of a deserrted road. I was only 1-1/2 miles from home though. Just when I think I have it all figured out, these Model A's throw me a curve ball.

10-11-2012, 01:59 PM	#12
zzlegend Senior Member Join Date: May 2010 Location: Reseda, Calif. Posts: 2,188	Re: Unexpected Exercise Well hope fully you found the problem Dave. Good luck with it and keep us updated.

10-11-2012, 02:15 PM	#13
bykerlad Member Join Date: Oct 2011 Location: australia Posts: 37	Re: Unexpected Exercise Can I ask what is a fire wire .?

10-11-2012, 04:06 PM	#14
Dave in Denver Member Join Date: May 2010 Posts: 67	Re: Unexpected Exercise fire wire as I have been told is a .060 length of steel wire placed on the block under the gasket between cylinders 1-2 & 3-4 to help prevent gasket blowout in this area.

10-11-2012, 10:58 PM	#15
columbiA Senior Member Join Date: Nov 2011 Location: B.C. Canada Posts: 1,746	Re: Unexpected Exercise Years ago I installed an original early 2- port Riley-with the spark plugs on RH side-and put well over 75,000 miles on it I just used the standard 2-port copper asbestos gasket and it never blew.Oiling the rockers was done by squirting oil thru two holes in each valve cover with 1/2 a felt insole under the covers.I have heard of a few people having trouble with the repro heads blowing gaskets.

10-11-2012, 11:15 PM	#16
Rich in Tucson Senior Member Join Date: May 2010 Location: Tucson, Arizona Posts: 374	Re: Unexpected Exercise "Just when I think I have it all figured out, these Model A's throw me a curve ball." The Model A had nothing to do with throwing a curve ball, you are in a totally different sport with a what you are running. And I wish you complete success, it will be fun when you get there!