Ticking in the front upper head ?

[xlfan]

Does the tick change under load and/or @ higher revs?

[Ratman1640]

Yes it does it goes away as I raise the rpms. its there at idle and about 1500 to 2000 rpms it goes away. I did a dry compression test this morning before coming to work and the rear was 125 psi and the front was 135. the motor was cold , Maybe its a sticky valve ?

[dirtymike]

Try running some 100% pure fuel(no ethanol) high octane, 93+ and see if it goes away. Dirty

[Ratman1640]

dirtymike, Ive always run 91 ,thats the highest I can get here but can put in some octane boost and Ive tried to stay away from ethanol gas. what about marvel mystery treatment ?

[dirtymike]

I don't use anything in my fuel tank but 100% gasoline, if they put in a can and sell it for a fuel additive to improve this or that i just figure its snake oil. Sonoco has 94 octane down here. Still haven't figured out how they can increase octane, but i aint no Fuel Guru. I know ole thug bitch don't wont to run on anything but pure high octane fuel. Its still a stock 1978 FX mill with points. Its pings and ticks on 10% ethanol every time. in a pinch ill put some in just to get home, then i drain it for the lawn mower. Dirty

[Ratman1640]

Well Ive dug a little deeper into the motor today and this is what I have found..... I pulled the front cylinder and piston there is deep scratches in the front and rear parts of the piston and the side of the piston looks fine but when I check the fit .001 to .002 per book I have .010 on the side of the piston and the front to rear is .001 and the cylinder looks the be ok but I don't have a bore gauge to check for trueness. I haven't got into the rear cylinder yet. I would think that the piston is supposed to be perfectly round lol . I think Im going to have to do a top end on the old girl !! any advice would be helpful . Thanks Guys        Mike

[JW113]

Mike,

No pistons are not perfectly round, they are "cam ground" which means oval shaped. The front/back thrush surfaces of the piston are where the load is against the cylinder walls, so that needs to be .002 minimum. The side clearance is intentionally made bigger so that when the piston gets hot, there is some room for the piston to expand and not seize in the bore.

Scratches on the piston is 'more or less' normal, all depends how deep they are. Does your finger nail dig into them when pulled across the scratch? I've seem some pretty horrific stuff come out of motors that seeming did not have any major symptoms. We like everything to perfect inside the motor, but the truth is they can take a bit of minor damage and wear and keep on working fine. Ticking noises are almost always the valve train. Almost! The bottom end tends to make more of a knocking or whurring noises if something is wrong. I would start with having the heads rebuilt if not done so in a while, same with the tappets. After that if that don't take care of it, then worry about bottom end. All in all, the bottom ends are pretty tough on these bikes, as long as they have not been abused. That said, I abuse the hell out of my twin cam and it seems to hold up just fine! (do as I say, not as I do!!!)

-JW

[Ratman1640]

JW, yes my finger nail does dig in to the scratches , I had a buddy check the bore today and we found that the cylinders are .014 over all out on the front and .009 out on the rear cylinder, I also found that the rear oil rings where seized in the groove so at this point I'm just going to get a new set of cylinders and piston kit. I checked the rods for side to side play and up and down and they seem to be fine. I know the guy that had this bike before I got it and he said it has a lot of miles on it , well over 200,000 miles on the bike but he's been know to stretch the true ALOT !!!! but here or there it need a top end done. Also I just seen the piston marked ,020 over So correct me if I'm wrong if I should just buy new instead of having the cylinders bored over and fitting new pistons. Thanks , Mike

[Hogman]

JW, yes my finger nail does dig in to the scratches , I had a buddy check the bore today and we found that the cylinders are .014 over all out on the front and .009 out on the rear cylinder, I also found that the rear oil rings where seized in the groove so at this point I'm just going to get a new set of cylinders and piston kit. I checked the rods for side to side play and up and down and they seem to be fine. I know the guy that had this bike before I got it and he said it has a lot of miles on it , well over 200,000 miles on the bike but he's been know to stretch the true ALOT !!!! but here or there it need a top end done. Also I just seen the piston marked ,020 over So correct me if I'm wrong if I should just buy new instead of having the cylinders bored over and fitting new pistons. Thanks , Mike

In MY Humble Opinion, IF it was Me, and Had OEM Cylinders, I'd Go for Another Over Bore & New Pistons/Rings. IF they are a Taiwan Ted Special, (I've Not Seen Much Good out of them,) Then I Would Look for a QUALITY Set of Cylinders, with Of course Pistons/Rings. This is All Just MY Humble Opinion.........  HTH Ratman.





ME

[fbn ent]

Get them bore gauged and see how bad the taper/out of round is. No issues with going .030" over in my experience. You will start seeing heat issues with larger. Have the heads gone through to and you will have a new top end to abuse .

[Ratman1640]

Ok another question .... I've checked the side to side play on the rods , I have .052 left to right play on the front rod and .015 on the rear side to side. What is normal? There is no play up and down using the dial indicator. The wrist pin play is from .001 to .002. Mike

[JW113]

Wow .014 on the front, and it's already .020 over bore? Sounds like you're looking at a set of .040 pistons to me.

I would definitely not replace the cylinders. You can get pistons up to .070 for a 74ci shovelhead.

For the con rod play you mention, do you mean clearance on the crank pin? Or how much you can rock them side to side? Remember the rods are fork and knife. The front one is the knife and will have much more side to side rocking than the rear.

I might be wrong but to me it sounds a little bit like you're pulling on a sweater thread. I just went through my whole engine, found quite a few things wore out or needing attention. Like the sprocket shaft timken bearing case insert was loose in the case, had to have that fixed. Also all the rod bearings and races were out of wear limits. I don't know how much dough you're looking to drop into this, it didn't cost all that much to completely rebuild the whole motor in my case. At least compared to a twin cam!

-JW

[Ratman1640]

JW Im talking about rocking the rod side to side ,I didn't think about checking the crank pin clearance, Ill do that and see what I have, thanks for the replay ...Mike

[Ratman1640]

Ok ..I have checked the end play between the rods and flywheel and its .028 and the specs are .005 to .025 if im not mistaken. so if that's the cast I guess its time to rebuild the bottom end also .

[JW113]

Two old sayings:

1. In for a penny, in for a pound
2. Better safe than sorry

Agree, sounds like you best get in there and see what's going on.

good luck!,

JW

[Ratman1640]

Thanks JW !! Its just money right lol

[Ratman1640]

Well here we go !! Rebuilt the motor which includes .... bored cyclinders 0.20 over for a total of 0.40 ,of course new pistons , lapped the vavles, took the motor to the local shovel guru and hes been working on shovels for over 30 years. So we checked the specs on everything thats in the motor and only thing that was found was that it need to be bored. So I put her all back together and guess WHAT !!!!!! She still has the knock !! Its still in the same place, on the front rocker arm shaft !! which like i said before everything is new and all the tolerances are within spec. So the only thing I know to do at this piont is to find a good used front rocker box and put it on and see if that wont fix it.  I really hate throwing money at something to see if it will fix it , thats NOT how I am. I know that the motor need to be refreshed and I'm good with that but its these little things that really drive me up the wall. Mike

[dirtymike]

From what i see you rebuilt the top end not the engine. It has been my experience that knocks come from the bottom end and ticks come from the top end. might want to check crank pin or rod bearings play. Dirty.

[Ratman1640]

I understand what your saying mike and I scored a front rocker box so Ill try that first and if it still continues Ill tear it down and do a rebuild on the bottom end . Thanks for the reply !! Mike

[fbn ent]

Take a real good look and make sure the rocker isn't touching the cover.....ask me how I know this .

[dirtymike]

when you place your hand on the rocker cover can you feel it.

[Pete_Vit]

I would look at the rocker arm bushings and rocker arm shafts check end play on rockers. check to see if you have a restricter fitting in the oil line. they used them to keep from using oil past the guides. it is a fitting with a smaller hole in it. check them all but it is on the bottom of rear rocker. that oil line goes into. do you have a clean tappet screen a lot of people don't clean them when they change oil. if you have hyd lifters adjust them 4 more flats on the front lifters.

not the same motor, mine an EVO, but I had to replace my rocker shafts after 103,000 miles, I had the ticking also, always thought it was a bad adjustment on the push rods, tappets were new cam new... once I did the rebuild my machinist checked my rocker shafts and replaced them.
guess I'm little late in this one 

[76shuvlinoff]

Push rod covers are not dancing around at all are they?

[Ultrashovel]

If all else fails, remove the cylinder head and check the clearance in the exhaust valve guide. Guides in Shovelheads are necessarily rather short due to the 90 degree included angle between the valves - thanks to the hemispherical combustion chamber design.

If the guides have excessive play, it will be nearly impossible to get them to hold an adjustment since they are seating differently from time to time.

Other than that, it sounds like the OP has done everything possible. It's a mystery!   

[76shuvlinoff]

Dad always said, "If it's bad it'll get worse then you'll know what it is".

And that made me do this