Ford Quadricycle

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So I ground the piston rings down and installed them...but with 2 rings per piston we have zero compression. I can hear air leaking from everywhere. Sooooooooo next will be trying to find all the air leaks which is a pain but has to be done.

Spark is strong, timing seems right, and the flywheel spins smooth so now to find those air leaks.
 
Lot's of air pissing past the piston rings. I only honed the cylinders...I never bored them which may explain all of the air leaking past the rings. I also ground the gap in the rings by hand. The rings were installed "as-is" but would bind up when they could not compress enough.

I'm going to order new rings and minimize the ring gap. If that does not work then I will have to make custom pistons (cast iron this time).

Also, I need a good source for custom fuel & water tanks for the Quadricycle.

Thanks...more coming soon.
 
Hey Chris,
Are you building this at Neit? I went there for collision repair and business management.

Kyle
 
Lot's of air pissing past the piston rings. I only honed the cylinders...I never bored them which may explain all of the air leaking past the rings. I also ground the gap in the rings by hand. The rings were installed "as-is" but would bind up when they could not compress enough.

I'm going to order new rings and minimize the ring gap. If that does not work then I will have to make custom pistons (cast iron this time).

Also, I need a good source for custom fuel & water tanks for the Quadricycle.

Thanks...more coming soon.

Hi Chris

What did you set the ring gap to? I doubt a new set of rings and/or new pistons will solve the problem.

New rings are made to run in round bores that are also parallel. OK, not precisely round or parallel, but within acceptable tolerances.

As a rough guide, you will get away with bores up to say 0.005" out of round which is a bit like starting with the bores of a well worn engine. Much more and you start to get blow-by because the new round rings don't seat in the bore properly.

You might get away with the bore up to 0.010" out of parallel, but the rings and pistons won't be happy. Better if it is also within 0.005". The above is considered very rough engineering when it comes to internal combustion engine practice. Luckily this is a slow revving engine...

As for ring gap, about 0.004" per inch of bore diameter will be ok. The ends of the rings should be carefully filed square to give the correct gap when the ring is placed in the bore.

But first, you need to measure the bores. If you are using a telescopic gauge and micrometer, you need to take 4 measurements working around the bore 45deg at a time. Write everything down. This will give you a fair (approx) indication of the roundness of the bores. Start just inside the ends of the cylinders.

Then measure at a point further down the bore, say where the water jacket weld is on the outside. And also at the crankshaft end of the bore. It's hard to imagine the cylinders being near round if they weren't bored and honed after the water jackets were welded on...

Regards, RossG

radial1951
_____________
 
Hi Chris

What did you set the ring gap to? I doubt a new set of rings and/or new pistons will solve the problem.

New rings are made to run in round bores that are also parallel. OK, not precisely round or parallel, but within acceptable tolerances.

As a rough guide, you will get away with bores up to say 0.005" out of round which is a bit like starting with the bores of a well worn engine. Much more and you start to get blow-by because the new round rings don't seat in the bore properly.

You might get away with the bore up to 0.010" out of parallel, but the rings and pistons won't be happy. Better if it is also within 0.005". The above is considered very rough engineering when it comes to internal combustion engine practice. Luckily this is a slow revving engine...

As for ring gap, about 0.004" per inch of bore diameter will be ok. The ends of the rings should be carefully filed square to give the correct gap when the ring is placed in the bore.

But first, you need to measure the bores. If you are using a telescopic gauge and micrometer, you need to take 4 measurements working around the bore 45deg at a time. Write everything down. This will give you a fair (approx) indication of the roundness of the bores. Start just inside the ends of the cylinders.

Then measure at a point further down the bore, say where the water jacket weld is on the outside. And also at the crankshaft end of the bore. It's hard to imagine the cylinders being near round if they weren't bored and honed after the water jackets were welded on...

Regards, RossG

radial1951
_____________

My half-scale Quadricycle cylinders were never bored and the engine runs great with lots of compression. I only honed them but I am also using an O-ring on each piston. Maybe this works for the smaller engine but not full size?

I could use 1-ring and 1-high temp O-ring and see if that helps.

Your right...we should have bored and honed after it was welded. I would have to take the entire engine apart right down to the weldment. Then I would have to send it out to be done...I don't think I could fit the weldment into the Bridgeport.

My old company had a giant horizontal mill. Not sure how much they would charge us though...

Thanks for the ring info Ross...very fussy stuff these IC engines.
 
Long story short...we honed the cylinders to match a new set of Pistons. I never really liked the aluminum pistons and the skinny rings. I wanted to make custom pistons with thicker rings all out of cast iron. I thought of an old Maytag engine I have and the rough size of the pistons...I double checked and the Maytag bore matches the Quadricycle bore of 2.5in.

So I bought 2 Maytag piston replicas from Ebay...they are the correct size and come with 3 cast iron rings. They fit perfectly into the cylinders. We need to work in the rings a bit before the exhaust heads get bolted on again.

I had to make custom wrist pins...added small flats on each end for set screws...I had to add the set screw holes to each piston, #10-32.

I also have to press out the old connecting rod bushing with a new one...to match the size of the new wrist pin.

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OK...I rebuilt the piston, rings, and connecting rods using the new wrist pins and new connecting rod bushings. I installed the piston assemblies into each cylinder using a pipe clamp, flat head screwdriver, and lots of patience. I had the exhaust heads off to check for clearances and everything spins nicely.

Now the air is pissing past the exhaust valves!

Now...I purchased the valves (they are Briggs valves) and I purchased the intake valves (they are Honda valves). I cut the valves seats myself using 90-degree C'sinks...apparently the purchased valves are not angled to 90-degrees.

I'm pretty good at making valves now so I'm going to make 2 exhaust valves and 2 intake valves all with an included angle of 90-degrees. I am also going to use slightly longer springs.

All of those things should help achieve compression...I hope.

I sprayed a little starter fluid into each intake valve and turned the engine over to see if it would at least turn over. It popped a couple of times and sent the flywheel over about half a turn on its own power...very weak without compression but at least I know how to fix the problem.

Now I need time to work on it...that has been the hardest part yet...time.
 
Hang on Chris!!!!

Try doing a compression test where you spin the engine over about 4 or 5 times and check with a gauge. Your compression will be low due to slow rotation but it could jump up upon faster rotation.
 
Thanks Steve...I was going to "run the rings in" by belting the flywheel to the lathe on low speed. Turning it over by hand is killing my back.

But I can hear and feel a ton of air coming out of the exhaust pipe during a compression stroke. All 4 valves are leaking air. I purchased the valves because that is what Dave Dunlavy had done for his Quad...but he must have know the seat dimensions.

I have never done a compression test...maybe I should try it.
 
how wide are the seats? if you have low spring pressure, the skinnier the better. im guessing you have a valve about 1-1.25 inch diameter. i would make a seat about .062 wide and see what happens.

Did you "lapp" the valves in. If so you might have to redo the seats. Dont use compound from the auto parts store. Use a finer polish and try to get a shiny finish.

Can you get pictures of the valves and seats?
 
Thanks Steve...I ended up making 2 exhaust valves...and re-touched the seats just slightly to about .100in wide seat. I made the valves with a 1/4-28 thread on the ends...I'm going to make a spring retainer that I can adjust spring tension with. The valves sit really good in the new seats...about 0.900in diameter. I used 1in stock, held the free end in a live center, and kept turning.

I also added a gland ring on the exhaust manifold pilot diameter. I know it will get real hot there so I will eventually switch over to a high temp o-ring.

Wednesday I'll make the spring retainers and try to run the engine again.

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I hope this works.

https://www.facebook.com/100010615121056/videos/294242807606221/

The 2 new valves worked....we got a ton of compression...engine ran great on a few squirts of starter fluid. Very exciting...however running on fuel drip may be the next big hurdle. BUT...the engine runs!

Chris, The Facebook link doesn't work for me, looks like I would need to be a member or something... any chance you might put it on your YouTube channel?

It's great to hear it now has compression and runs. Did you fit viton o-rings to the pistons or just running the standard iron piston rings?

Regards, RossG
radial1951
____________
 
So we have great compression in one cylinder but almost nothing in the other. Most of the air is leaking past the intake valve. So I decided to re-design the intake valves and seats to make them easier to seal...more to come.

We completely over-hauled the front suspension, fixed a bent connecting rod, and neatened up the ignition wires. We also added a full radius on the end of the speed adjuster. Also put larger O-rings on each exhaust manifold.

And...the Quadricycle is on the ground (for the second time), hopefully we don't have to put it back on the dolly again.
 
Sounds like progress!

Went to the old car festival at the henry ford museum today. Saw 2 replicas driving around the village.

That must be awesome to see them driving around. The Ford museum is on my bucket list but it is so far away...one day.
 

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