1955 Buick Roadmaster Starting Issues

[195354]

Tough to pin this down listening to the video. I am in the sticking valve camp.  I did notice you can hold a fairly low RPM and it makes the noise. Can you

adjust the carburetor to hold this speed then use a stethoscope or anything like a long bar to pin down the noise. I put my thumb over the end of a long bar and then hold the bar to my ear. I would try each valve cover first if you hear it at valve cover that is were l would go next.

Try and depress  the valve on each cylinder. I have bolted a chain to the engine in different spots then create a loop put a bar through that and push down each valve. I used a 2x4 on end in the past. Rocker lever will need to be removed be careful to push on the valve stem not the spring.  You don’t want to dislodge the valve keepers.
When you find one that is slow to return you found the issue.

I had a stove bolt Chevrolet with a similar problem. Would backfire once in a while this was after it ran like a champ for about 500 miles. One day the valve stuck on a hill. Once l was going down the other side the temp dropped just a bit back to normal. The above method is how I found my issue. Machine shop had the guides tight painful pulling that head over a fender.

Steve

[EmTee]

I'm thinking it's possibly sticky valves since the sound seems to be channeled through the intake manifold and carburetor.  I would pull the valve covers and spark plugs.  Set a dial indicator on each rocker arm (start with the intake valves) and roll the engine with the starter looking for anything other than smooth needle movement.  Any momentary twitch or jump would be a clue.  If you find a suspect, try spraying some WD-40 on the valve stem and repeat.  If this turns out to be the issue, I'd probably just drive it for a couple hundred miles and keep a close eye on it.  Chances are the guides would wear-in and everything will be OK.

[KAD36]

Do you recall what adjustments you were making when the rpm moved from idle to off idle.  It sounds like something is getting sucked shut if not a misfire or crossed wire.  Something mechanical in the valve train would seem more regular imho.

 

Also back to your “ran great before integration” comment - how long and what rom did it run at? What temp did it get to vs the temp it’s at now when noise happened.

 

If noise was happening regularly at idle I missed it in the video

Edited September 1, 2023 by KAD36 (see edit history)

[buickbrothers]

Ok gents. I know the problem after a long day of evaluation. I'll let you guys duke it out as to who was closest to the problem. A rocker arm on cylinder 2 snapped off so the exhaust valve was not moving. I've attached the pic. I'm thankful to my heavenly father it was just this and I have a spare replacement! Could have been a bigger problem!

[avgwarhawk]

2 minutes ago, buickbrothers said:

Ok gents. I know the problem after a long day of evaluation. I'll let you guys duke it out as to who was closest to the problem. A rocker arm on cylinder 2 snapped off so the exhaust valve was not moving. I've attached the pic. I'm thankful to my heavenly father it was just this and I have a spare replacement! Could have been a bigger problem!

Interesting. It must have taken some force to break a rocker. Did you check the valve is moving? 

[EmTee]

1 hour ago, avgwarhawk said:

It must have taken some force to break a rocker. Did you check the valve is moving?

That ^^^.  Now that the 'what' has been answered, the next question to be answered is 'why'...?

[Brooklyn Beer]

question should also be have you recovered all the broken parts ?

[old-tank]

3 hours ago, buickbrothers said:

. A rocker arm on cylinder 2 snapped off 

I had that happen along with other destroyed parts when the machine shop installed shims under the outer valve spring that covered the recess for the innerl spring .  Check closely that there's no valve bind on that valve and others.

[EmTee]

9 hours ago, old-tank said:

Check closely that there's no valve bind on that valve and others.

That was my first thought also...

[Brooklyn Beer]

Would pulling all the push rods out one by and checking for straightness be a good indicator of which valves could have issues? 

[avgwarhawk]

2 minutes ago, Brooklyn Beer said:

Would pulling all the push rods out one by and checking for straightness be a good indicator of which valves could have issues? 

It's helpful. Word of caution. Sometimes the lifter will come up out of its bore as the push rod is pulled. When or if that happens the intake will need to be removed to put the lifter back in its bore. 

[KAD36]

Glad you found it.  Assuming these were reproduction?

 

Consider what EmTee said and check the valve bind specs for your inner and outer valve springs compared to the lift on your cam and the ratio of your rocker arms if you’ve not already done so.  Myself and others had problems during our rebuilds with some aftermarket valve springs not being able to compress enough to accommodate aftermarket camshaft profiles and valve head work - tolerance stack up issues.  Granted I used 1.6 ratio rockers vs 1.5, and the aftermarket cam at the time was promised to “work” but no specs were provided and it had to be dialed in.  The factory valve springs will compress to under an inch, some aftermarket ones won’t.  Guy on the HAMB forum did the math on a couple suppliers.

 

Giving credit where credit is due, see page 6 of attached post:

 

https://www.jalopyjournal.com/forum/threads/engine-builders-why-is-my-new-322-breaking-rockers.986654/page-6

 

It could also be a part quality issue if aftermarket.  Looking forward to hearing it run right - looks great so far.

 

 

 

Edited September 3, 2023 by KAD36 (see edit history)

[buickbrothers]

Thanks for all the inputs. First, the rod is bent/scored pretty deep on the side, so I'll now have to replace it.  As I was being diligent, by checking the other rods on the driver's side while I had the rocker arm assembly out, a lifter came out of its bore. So, now I'll need to remove the intake and valley. I was planning to do this anyway because I noticed a little side rubbing on a couple of the rods on the other cylinders. These rods are thicker than the original rods that came out of the car. I did question this with Centerville and they indicated they use these same rods in all their rebuilds. I got all the parts for the engine rebuild from Centerville Auto in CA (Home | Centerville Auto Repair (nailheadbuick.com)) which only works on Buick Nailheads. I had several calls with them and spent some time planning what parts to buy new or reuse. As a shorter reference, the only reuse items were inner/outer valve springs, cam, crank, rocker arm assemblies and oil pump although I had the cam and crank turned at the machine shop. I also refurbished the oil pump. 

 

So why am I seeing some side rub marks on a couple of rods? I'll be checking the passenger side next and will evaluate everything while I have the intake/valley open. When I assembled everything, I manually turned the crank and checked everything for clearances and to ensure everything was moving correctly with no issues. Seems no matter how hard I try to do it right on this car, it fights back. Here's a pic where everything is exposed:

[avgwarhawk]

Kind of figured a lifter would come out of the bore.  I have seen some grind the push rod hole to accommodate the thicker diameter rods. 

[old-tank]

1 minute ago, avgwarhawk said:

Kind of figured a lifter would come out of the bore.  I have seen some grind the push rod hole to accommodate the thicker diameter rods. 

Detailed on one of Mudbone videos.

[avgwarhawk]

47 minutes ago, old-tank said:

Detailed on one of Mudbone videos.

Yep!  👍

[avgwarhawk]

Mudbones videos 

 

https://youtube.com/@dyna1955?si=CtrOlpG7PtN1wFTq

[EmTee]

7 hours ago, KAD36 said:

Granted I used 1.6 ratio rockers vs 1.5...

That's another possibility - 1.6 rocker where a 1.5 was needed.  Something else to check.  The fact that these stiffer pushrods are buckling really suggests a valve spring bind issue.  (That assumes it isn't valve float induced by the 7500 RPM tachometer redline...) 

 

Edit: I assumed the rub was due to the pushrod beginning to bend.  If it's rubbing simply because it's too fat for the hole in the head, that's something else...

 

Edited September 3, 2023 by EmTee (see edit history)

[old-tank]

2 hours ago, EmTee said:

it's too fat for the hole 

That's the usual issue without massaging.

[EmTee]

3 minutes ago, old-tank said:

That's the usual issue without massaging.

Wait - what were we talking about...? 

[KAD36]

7 hours ago, buickbrothers said:

As a shorter reference, the only reuse items were inner/outer valve springs, cam, crank, rocker arm assemblies

If am understanding the above correctly, cam rocker arms and inner outer springs are factory original?  If so it would seem unlikely that would induce spring bind if factory lift and ratio are retained imho.  Are the only new parts in the valve train the pushrods and lifters? How do the lifter and pushrod lengths compare to original?  55 and 56 lifters and pushrods need to stay a matched set due to different lengths between the years - how consistent are they.  Some type of interference bent that pushrod, not just rubbing.  Adjustable pushrods are a little more expensive but help offset effects of valve stem height and seating differences if the heads were worked on multiple times and help ensure a consistent preload.  While not mandatory fwiw went that route on my second rebuild with good results.
 

 +1 on filing to accommodate the larger diameter pushrods per Muds video.  Let us know what you find

[old-tank]

Valve stem height

1.525 to 1.550 measured (in inches) from valve cover rail to valve stem tip.

valve stem clearance in guide:
0.0025 inlet
0.0030 exhaust

 

These are the specs that the machine shop should have referenced.  If the valve stem is too high you could get spring bind when the lifters pumped up.

If they put shims under the outer valve springs that covered the recess for the inner valve spring you will see severely compressed inner spring with no load...removing the spring will be definitive.

[buickbrothers]

Yes, cam, crank, rocker arms and both inner/outer valve springs are still factory original. I do not see any shims under the outer springs - are they supposed to be visible, or do I need to remove the springs? All other valves are working correctly on the car so far. I'm kicking myself for not doing the valves myself, but I had neither the experience or tools for this activity and I thought the machine shop would do this correctly. I did provide all the spec's and the tech sheet do's/don'ts related to nailheads.

 

I have removed the intake manifold, valve covers, and the lifter valley cover. The new rods and lifters were the same length as the old rods/lifters. I did see the adjustable rods but wasn't sure of the benefit based on having fixed rods originally. These were $205 vs $75 for the non-adjustable at Centerville. I can switch to these since I'm now in a position to do so. However, I'm trying to understand if only this one valve is a problem why would I change all the rods and risk introducing another problem? I need to determine root cause on this one valve/rod issue to determine the best path forward. 

[avgwarhawk]

3 hours ago, buickbrothers said:

Yes, cam, crank, rocker arms and both inner/outer valve springs are still factory original. I do not see any shims under the outer springs - are they supposed to be visible, or do I need to remove the springs? All other valves are working correctly on the car so far. I'm kicking myself for not doing the valves myself, but I had neither the experience or tools for this activity and I thought the machine shop would do this correctly. I did provide all the spec's and the tech sheet do's/don'ts related to nailheads.

 

I have removed the intake manifold, valve covers, and the lifter valley cover. The new rods and lifters were the same length as the old rods/lifters. I did see the adjustable rods but wasn't sure of the benefit based on having fixed rods originally. These were $205 vs $75 for the non-adjustable at Centerville. I can switch to these since I'm now in a position to do so. However, I'm trying to understand if only this one valve is a problem why would I change all the rods and risk introducing another problem? I need to determine root cause on this one valve/rod issue to determine the best path forward. 

 

Other possible reasons for a broken rocker that have not been explored:

 

1. Old varnish gas gummed up the valve

2. Piston struck the valve. 

 

What I would do is replace the broken rocker and push rod. Assure the rods are not rubbing the cast iron access holes in the head.  Then manually rotate the engine s number of times to assure no binding or possible piston strike.     

 

Also, it has been awhile since working on my valve train.  Please ensure the rocker arm shafts are clocked in the correct position for proper oiling of the rocker arms.    

 

 

Edited September 5, 2023 by avgwarhawk (see edit history)

[buickbrothers]

Update: the valve was not stuck. I dropped in an original rod and slowly turned the crank and the valve moved just fine without any effort. I'm leaning towards the issue of rod clearance which is very disappointing. I see some rub marks on other rods, but nothing extreme. However, some are touching the rod hole. I see a bigger rub mark on the rod hole of the rod that bent. So now the challenge is doing the boring without getting metal shavings in the engine and while it's in the engine compartment. They should not sell these as rods for these engines with no warning that boring is required to ensure clean clearance. I plan to replace all these with the adjustable rod's although the book says lashing is accounted for through the design of the lifters and that is why there is no adjustable rod/rocker capability in the engine design for lashing per the book. I'll order parts tomorrow and it's a wait game after that. 

[KAD36]

Also, were the heads milled at all?  That and or valve seats from X number of valve jobs could affect the geometry.  Attaining the valve stem numbers with the reference block Willie mentioned was the process used on my first rebuild and as one might expect it provides a reference point to  “compensate” for heads that had been worked on a couple of times with different resulting seat depths - it gets the geometry and preload consistent and back to factory specs.  Adjustable pushrods obviously also essentially do the same thing without having to grind the stems - they make up for variation in seats, head milling, wear etc etc so lifter preload and valve lift is all consistent.  Either way you go the end game is the same.  I didn’t fully appreciate this until doing the math then the measurements with a dial indicator and finding my valve stems were running wild.  After a bunch of late night phone calls to some forum folks who had rebuilt their 322s the “Tank” set me straight yet again.

 

Agree it’s best to find root cause and corrective action, but don’t drive yourself too nuts if you can’t find it.  Been there done that.  Fall back on good shop practices and accurate, consistent measurements.  You probably already knew that.  I don’t recall the adjustable push rods on my second rebuild being too different a diameter than those other aftermarket ones but there were also no rub marks on mine so might have just lucked out.  Plus it felt better to dial in a consistent preload.  More things to swear at while holding the locking nut and spinning the adjustment nut and trying not to drop the wrench and wait was that just 2/3 of a turn or 3/4 Cripes better start all over.  16 freakin times.  That’s my story and sticking to it  Curious if you find anything more.  Thanks for keeping us updated.

[EmTee]

Were hardened seats installed?  That would be another possible cause for spec variation, although if done properly it would theoretically allow seat heights to be restored to 'as-new'.  I think KAD36 is right; reassemble it paying attention to the individual valve stem heights/clearances.  At least the adjustable push rods will make that a bit easier to accomplish.

 

That said, I'm wondering whether the push rod associated with that particular valve rubbed on the head hard enough to stick in place, just enough mimic a stuck valve.  Excessive clearance should have led to an audible tap - but maybe not heard if it happened while driving.  If so, maybe shock from the clearance fractured the rocker casting at a pre-existing weak point?  As Ken said, the actual cause may never be known with certainty...

[KAD36]

19 hours ago, buickbrothers said:

So now the challenge is doing the boring without getting metal shavings in the engine and while it's in the engine compartment.

Would shaving cream work there to catch the filings then shop vac it out?

 

[old-tank]

1 hour ago, KAD36 said:

Would shaving cream work there to catch the filings then shop vac it out?

 

Grease on a slow cutting tool...maybe even a rat-tail file.  Wipe then flush with mineral spirits catching on some rags.

[buickbrothers]

I've been waiting on a part (intake gaskets) to finish putting the engine back together for a start-up. I will let everyone know Saturday the result. In the meantime, I put a post out on another head scratcher - electrical. Please weigh in on that one... Thanks.

[avgwarhawk]

29 minutes ago, buickbrothers said:

I've been waiting on a part (intake gaskets) to finish putting the engine back together for a start-up. I will let everyone know Saturday the result. In the meantime, I put a post out on another head scratcher - electrical. Please weigh in on that one... Thanks.

Rotate the engine by hand before setting fire to the spark plugs.  When I replaced my heads, rods and lifters I rotated the engine by hand. Turned it 1/4. Cluck. Reversed the rotation. Clunk.  It would not rotate past these 1/4 turns. What in Sam Hill? Tried it again. I hear a clunk at the rear axle. For the love of Heaven....I left the manual transmission in gear.  Once in neutral the engine rotated by hand without issue. She fired up like a champ. 

 

Post a video of the start if you can.  😃

[buickbrothers]

Ok all, she's back together and running again. Here's the video: https://youtu.be/L0ZC6Yi-jgk

 

I've re-checked timing, reset carb, fast idle, etc. It's running pretty smooth but I'm still hearing a slight/mild misfire/timing condition - not a pop but a muffled not quit in sync sound. For reference, the engine has less than an hour run time. Is it still breaking in or do I need to check something else? Could I be a tooth off on the distributor? At least we are running again! Thanks for all the help.

[avgwarhawk]

15 minutes ago, buickbrothers said:

Ok all, she's back together and running again. Here's the video: https://youtu.be/L0ZC6Yi-jgk

 

I've re-checked timing, reset carb, fast idle, etc. It's running pretty smooth but I'm still hearing a slight/mild misfire/timing condition - not a pop but a muffled not quit in sync sound. For reference, the engine has less than an hour run time. Is it still breaking in or do I need to check something else? Could I be a tooth off on the distributor? At least we are running again! Thanks for all the help.

May Lord that is music to my ears!!!  Glad she is happy and running! 

 

 

[EmTee]

This engine was completely rebuilt, correct?  The timing was set to specification, right?  Try connecting your timing light and watch the crankshaft mark as the engine runs.  Does anything happen to the observed timing when the engine 'hiccups'?  Also connect a dwell meter and watch that as well.

[avgwarhawk]

New rings?  Let them seat. May take a few hundred miles or so. 

[Brooklyn Beer]

I enjoy reading problems being solved as a group

[buickbrothers]

Yes, engine was completely rebuilt. I've noted the only parts I reuse: rocker's, cam/crank, piston rods. Cam/crank polished. All remaining parts are new - bored for 4.25 pistons. I had the timing light on it yesterday when I reset/reverified everything - set at 5 degree's. Rechecked after a good 15 minutes run time and still sitting on 5 degree's at idle. I'm sure the rings are still seating since engine has less than an hour run time.