47 knucklehead, new built engine with zero compression

[ricmoran]

New built 47 knucklehead, Truett & Osborn flywheels, Andrews S cam, heads rebuilt by Head Hog. Engine sat for 3.5 years due to health issues. Over the last year finally was able to get the bike assembled. When the engine sat, I did turn the engine over several times every 4-5 months as well with lubricant injected into cylinders. No compression when push rods installed, has compression without push rods installed. Called Andrews regarding cam being timed right to drive gear. That all checks out per their advice of how they line up drive gear to cam shaft. All gears in the cam chest are properly timed as well and checked by visual inspection, not once, but twice. Removed front head rocker covers, rocker arms move easily by hand upwards away from valves & without pushrods installed but did not remove rear covers to inspect. Thought check the front head 1st, easier to get to the rocker arm assembly. Squirted oil in front cylinder, 35 psi front when kicked several times, rear zero. Valve timing is correct per T&O advice as well as Andrews as stated. Anyone have any suggestions?

[Rubone]

Sorry to hear about your health Ric. Hope you are doing better. Wondered where you went?
You might try some deisel fuel in the cylinders. If the rings are stuck it could free them and no issues with it mixing with the oil.
Robbie

[ricmoran]

Thank you for the tip Robbie, will give it a go. Had a ladder fall in 2006 and the periphial injuries caught up to me after surgery in 2012 over a 3 year period. Was at a point that walking was tough to do. Torn iliolumbar ligament on the left Sacroilliac joint has caused so many issues that building the 47 was difficult to accomplish amongst other things. Thankful that no opiods were used over the years as that issue has devastated so many. Will advise result of diesel treatment for the rings.

[dommi7]

Ric,
When you say no compression, do you mean reduced compression - or none at all? No comp means to me valves are staying open. Valve stuck in the cast iron guide is possible on a motor that has sat. But you say the problem is only with pushrods installed. Sounds like insufficient valve lash or too long pushrods or a pushrod that is not sitting in the right spot. But I'm no expert.

[Rubone]

Ric, are you sure the clutch isn't slipping giving the impression of no compression? Are you sure the engine is actually turning over?

[ricmoran]

Ralph, zero compression even when there is slight up and down play allowing maybe .005" excess lash at the rocker arm and valve.

Pushrods are aluminum and were run in my 39 EL& the engine ran fine but needed head work and piston cylinder work fr9m wrong tolerances set up by the 1st assembler of that bikes engine & before my time of ownership.. I changed them to go with chromemolly pushrods as it seemed to me the aluminum pushrods were noisier than steel pushrods. The 39 ran fine with them. All pushrods are set loose running the compression test.

Quote from Ralph:
Ric,
When you say no compression, do you mean reduced compression - or none at all? No comp means to me valves are staying open. Valve stuck in the cast iron guide is possible on a motor that has sat. But you say the problem is only with pushrods installed. Sounds like insufficient valve lash or too long pushrods or a pushrod that is not sitting in the right spot. But I'm no expert.
Ralph

[ricmoran]

Ric, are you sure the clutch isn't slipping giving the impression of no compression? Are you sure the engine is actually turning over?

Robbie, yes the clutch engages and spins as it should.

Went from 31/32" pressure plate to clutch spring retainer measurement to near 1/2". I have marks on 1 of the 5 finger studs on the clutch hub as the stud was a problem threading the adjustment nut onto as the stud had a burr on it. I marked it to remind myself and my son (this bike is being built by myself for him) to take care when servicing the clutch as any more threading issues, that stud may need to be replaced. So the marked stud changes location when kicked.

When kicking over with the compression gauge nstalled in 1 cylinder and watching the piston in the other cylinder via the vacated plug hole you can see the piston traveling up and down. Running the heavy duty police clutch plates as well and these are thicker than stock plates by fractional size as well so the adjustment is tighter at 31/32" measurement than stock plates.

Treated the cylinders yesterday with diesel, kicked it over several times and sprayed a little more into the cylinders & let it sit. Sat for about 20 hours.

Just tried again, 20 psi in front, zero compression in the rear.

2015 saw a terribly hot summer here, engine sat in sons old bedroom, oil used was CarWell cp90 rust inhibitor, about a 8 weight oil and thought that being that light weight as well as a rust inhibitor would help. Am thinking perhaps that combined with assembly lube may have impacted rings by gunking the rings up.

But after spraying more diesel into the cylinders after 1st compression check today, nothing changed. Am suspicious that rings are severely impacted by over zealous lube addition but at this point not certain.

Was getting rag blow out of the carbs venturi when used to plug carb to try to induce fuel into the manifold prior and before diesel fuel treatment. Thought its time to go further into the engine but stopped short before posting my initial post asking for help here on the forum.

The intake manifold is off, rags are stuffed into intake spigots and yet after treatment are again getting blown out. Inserted the rags because of misting diesel when sprayed into the cylinders cause a cloud of diesel to escape partially open intake valves with pushrods installed. Am getting good valve travel on the front head as watching the rocker arms move when kicked on the front cylinders exposed intake/exhaust rocker arns as the covers were removed to check oil seal to rocker arm tolerance for free moving rocker arms.

I understand some reversion can occurs at valve overlap but what I am seeing is beyond normal.

Short of top end tear down, will let the diesel fuel sit in the cylinders for a couple more days, kicking it over every few hours and treating again with diesel. Am only using 2 -4 oz of diesel per cylinder at this point as well.

Thank you for the questions as this one has me stumped and without shop resources of fellow mechanics you guys here are a tremendous resource of knowledge.

[ricmoran]

Playing detective and some help from Lee at Knucklehead theology, he recommended inspecting pinion shaft for slipping by lining the crankpin into the timing hole via both pistons being at the top of their travel & not tdc.

Everything checks out as Lee advised, large pinion shaft spline is at the 6 o'clock position. Robbie did the diesel routine and and have compression in the front cylinder with the pushrods adjusted with a lot of slop. 60 psi front, zero with the rear cylinder.

Am in thought that head's valve & rocker arm assembly may be playing into this but how is thus far not known.

[ricmoran]

Are knucklehead, panhead and shovelhead pinion shaft gears interchangeable, by that I mean fit the pinion shaft? Comparing the pinion shaft gear on the 47 knuck to an imaged knucklehead S&S pinon shaft gear shows the gear on the 47 off by 5 teeth in correlation to the timing mark that aligns the to the distributor drive gear.

[Jerry Wieland]

Far as I am aware the pinion gear in the 47 if it is OEM would have been used from 1939 thru 1953 so yes early panhead gear would also work. I am not aware of what S&S has. Jerry

Are knucklehead, panhead and shovelhead pinion shaft gears interchangeable, by that I mean fit the pinion shaft? Comparing the pinion shaft gear on the 47 knuck to an imaged knucklehead S&S pinon shaft gear shows the gear on the 47 off by 5 teeth in correlation to the timing mark that aligns the to the distributor drive gear.

[Rubone]

Ric, It is possible that the pinion shaft was changed to the '55-'57 type in which case it could use the '54 up gears as shared with later Pans and Shovels. If it has splines it is early (as Jerry describes above), if it on a taper and held with a nut it is late. Either can be used with the appropriate matching parts. In any case all the timing marks are common to all OHV models as far as lining them up goes.

[ricmoran]

[QUOTE=Rubone;169405]Ric, It is possible that the pinion shaft was changed to the '55-'57 type in which case it could use the '54 up gears as shared with later Pans and Shovels. If it has splines it is early (as Jerry describes above), if it on a taper and held with a nut it is late. Either can be used with the appropriate matching parts. In any case all the timing marks are common to all OHV models as far as lining them up goes.[/QUOTE/]

The shaft is splined. Images of the pinion shaft gear taken on the shaft vs oem with the oil pump drive gear and pinion shafte gear imaged. Looking closely at the timing marks are a wide deep V on the installed gear, deeper than the oem marks seen on the oem gear. Can see where 1 oem mark faintly remains as the face looks as if it were ground and timing marks removed. Comparing the wide spline, the installed gear shows the timing gear mark 5 teeth away from where it is on the oem gear. When I saw that all I could think of is, why?

Thank you for taking time to write your replies.

Am going to source a correct pinion gear if I do not have one in my spare parts mix. Will advise results.

[ricmoran]

Put it all back together, hard starting & ran rough but was able to start the bike 3 times. Now its a matter of a couple oil leak resolutions, getting the correct timing and carb adjustments, letting the engine run up to operating temperature, shut down cool and tighten cylinder and head assembly. Thanks again for your input.

[Davestune]

Playing detective and some help from Lee at Knucklehead theology, he recommended inspecting pinion shaft for slipping by lining the crankpin into the timing hole via both pistons being at the top of their travel & not tdc.

Everything checks out as Lee advised, large pinion shaft spline is at the 6 o'clock position. Robbie did the diesel routine and and have compression in the front cylinder with the pushrods adjusted with a lot of slop. 60 psi front, zero with the rear cylinder.

Am in thought that head's valve & rocker arm assembly may be playing into this but how is thus far not known.

I had to swap out my shafts and rockers, i had early ones in my 47 , they was moving and getting hung open by the covers.
drove me nuts

[ricmoran]

I pulled 3 of the 4 rocker covers but did not see any evidence if rocker arms hitting the covers. Since this was a total basket case of a lot of mismatched parts I did have concern of that. 1st set of original rocker arms bought where the arm works on the valve stem were ground down too far to work, 2nd set, no issues, thankfully. Attachment is of bike near completion.