[Dr. Zo]

maybe not. if it just has the notch, cleaning it up with a needle file will probably do it. you dont want to take em out if you can help it because the new ones have to be hand fitted for length and endfloat and then reamed, which takes a special tool kit. i have found lately that new ones come pre-sized, which means too big to start with.

on the key, i would warm it with the torch and then persistently tap at it from as far underneath as you can get until it tips up and comes out.

OK, I'll give it another try. So it seems that most rebuilders keep the cam bushings as they are a bit difficult to replace.

 

[GrandPaulZ]

I'd be wary of a notched cam bushing. It would almost certainly allow WAY more runout in that direction, then the specified miniscule amount.

This a a very bi-polar engine. It's partly happy (cool hotrod parts), and partly bodged (obvious bodges in photos).

Still cool overall, just needs help.

 

[Dr. Zo]

I'd be wary of a notched cam bushing. It would almost certainly allow WAY more runout in that direction, then the specified miniscule amount.

This a a very bi-polar engine. It's partly happy (cool hotrod parts), and partly bodged (obvious bodges in photos).

Still cool overall, just needs help.

Yes, so it looks like I will be replacing some bushings on this motor. If I'm replacing the exhaust set, would it be smart to replace the bushings for the intake cam also?

 

[speedrattle]

might as well

 

[GrandPaulZ]

Probably get economy of scale (with the machinist) by doing both sets...

 

[Dr. Zo]

Today I made some more progress. I was able to remove the sludge trap plug with a tool I filed to fit the plug. There was almost nothing inside the trap - which I have not removed. I’ve heard a way to remove the trap is to tap it and then insert a bolt of the same thread and remove by tightening a nut on the bolt once it is engaged in the trap. I imagine there are some other ways to get the trap out.

Also, I finally was able to remove the exhaust cam woodruff key to allow me to remove the cam. You can see that the bushing had a significant portion cut out, most likely due to the key being jammed against it? I’m not really sure how the bushing got this way. The cut out portion was there before I attempted to remove the key. I may have added a bit to the gouging when I was attempting to remove the key, but not much. Any ideas of how the bushing got this way or what kind of effect it would have on the engine’s functioning?

 

[Dr. Zo]

I’m trying to get some idea of the purpose for which the megacycle cams on this engine were designed. The first photo is from the exhaust cam, second and third from the intake cam. Seems the numbers on both are:1060 (and) 12.0

 

[Dr. Zo]

I’m looking for sintered bronze camshaft bushings and am having difficulty finding a set on the web. I appreciate any comments on where to find these. From what I’ve read, sintered bronze seem like the best option for me. Thanks.

 

[Dr. Zo]

Also, I will need to purchase a torque wrench for my bike. I am wondering what range of torque/ft pounds I should have for my 1969 T120R? Thanks.

 

[StuartMac]

Hi,

trying to get some idea of the purpose for which the megacycle cams on this engine were designed.

Megacycle are still around, ask them?

torque wrench
what range of range of torque/ft pounds

If you look in the Workshop Manual at the end of the "General Data" section, there's a list of important torque values.

That said, bear in mind the low ones are the important ones, getting them wrong leads to stripped threads and/or broken fasteners. When I went to buy my first torque wrench, I couldn't get one that covered the whole range, I ended up buying one that covered 6-40 ft.lb. and another that was ... errr ... bigger ...

Hth.

Regards,

 

[Dr. Zo]

Hi,

Megacycle are still around, ask them?


If you look in the Workshop Manual at the end of the "General Data" section, there's a list of important torque values.

That said, bear in mind the low ones are the important ones, getting them wrong leads to stripped threads and/or broken fasteners. When I went to buy my first torque wrench, I couldn't get one that covered the whole range, I ended up buying one that covered 6-40 ft.lb. and another that was ... errr ... bigger ...

Hth.

Regards,

Stuart,
Thanks. I have sent a note to megacycle to get some information. However I learned from speedrattle that, "1060 was megacycles hot street cam from the 1970s. they still sell that grind, but call it 510-65.". So that is good to know! Thanks for the information about torque wrenches too.

 

[GrandPaulZ]

I use a good ol' Craftsman 3/8" drive beam torque wrench. Still works almost 50 years later, more than accurate enough.

 

[Dr. Zo]

I use a good ol' Craftsman 3/8" drive beam torque wrench. Still works almost 50 years later, more than accurate enough.

thanks!

 

[Dr. Zo]

I finally removed the cam bushings last evening, using the technique with a tap. Tapping them a ways and then they started to move and came out. Easier than I thought.

Apart from the damage that was existing in the right exhaust bushing, it seems good that I am replacing all of the bushings. It appears that all of the bushings are sintered bronze - except for the left intake bushing which is solid bronze. I would think this is not a good idea to mix bushing types?

 

[GrandPaulZ]

Yep, at least one was replaced. That's probably the event when the other one got damaged.

I'd get all 4 the same, and HOPEFULLY the bores are all the same diameter.

 

[Dr. Zo]

Some Tappet advice needed. I had thought that 3 or my tappets were the “R” type and 1 was not. Well, after carful inspection I can make out an “R” on all 4 tappets. So I suppose the means the previous builder was consistent. This being the case, the exhaust tappets do not have a machined cut away space with an oil hole. My engine is from 1969 and I thought that this meant it should have the exhaust tappets with the machined flat area and an oil hole, which should face out on assembly of the exhaust tappets. Do I have my facts straight?

Also, I am wondering if the case halfs are from different engines? As I put the cases together the casting doesn’t seem to match. As to the oiling of the exhaust tappets again, on the right side case, the exhaust tappet oil feed drillway is plugged. So perhaps this is why the exhaust tappets have no cut out and oil hole. Perhaps stranger again is that the cylinder (An old Routt big bore) does not seem to have an exhaust tappet oil feed drillway that would correspond with the drillway in the case. If any members can shed some light on this tappet sling question I’d appreciate it. From what I’ve read, the 1969 engine should have the exhaust tappet oiling system.

Thanks!

 

[Dr. Zo]

Hydro blasting advice. I am going to take my engine parts to be hydro blasted. I am curious as to which parts can withstand this process. Obviously the cast engine cases - but does anyone also have the covers blasted? Or is this something that ruins them? Thanks for any advice.

 

[StuartMac]

Hi,

Hydro blasting

Mmmm ... depends on the details of the process. If it's some more-solid media - e.g. grit, beads, balls - in water at high pressure, I wouldn't. Aluminium alloy engine parts were mostly sand-cast, they're relatively soft, solid media in liquid at high pressure can actually be driven into the ally, cleaning won't remove it but when the engine is used and heats up, expansion of the castings releases solid blast media into the oil, to do nasty things to bearings, pump, etc.

Otoh:-

. Soda blasting's only residue is water-soluble; if you have access to a compressor, your "Harbor Fright" sells gun and blasting soda; do it outside, wash away the remains when done.

. Dry-ice basting doesn't leave any residue.

covers blasted?

Would need polishing again?

wondering if the case halfs are from different engines?

Regret I don't know enough to comment on your tappets questions, but your crankcase photos. at least show good alignment around the holes for the tappet guide blocks?

Nevertheless, most important is whether main and camshaft bearing housings are concentric between the two crankcase castings. Meriden achieved this by bolting crankcase castings together and then machining them together. As castings had to come apart subsequently for engine assembly, to ensure castings machined together were reassembled together, each 'half' was stamped with a code on the lower engine mounting lug (note this isn't the "engine number" as stamped on the drive-side crankcase at the end of assembly)

If your engine's crankcase castings either have different codes or none at all, you might wish to have the aforementioned alignments checked. Any competent machinist can make a couple of shafts to check crank and cam bearings; however, the finished accuracy necessary probably means grinding which could cost you two or three hours. A possible alternative is sending the cases to Coventry Spares (John Healy), who has the shafts to do the check.

Hth.

Regards,

 

[Dr. Zo]

Hi,

Mmmm ... depends on the details of the process. If it's some more-solid media - e.g. grit, beads, balls - in water at high pressure, I wouldn't. Aluminium alloy engine parts were mostly sand-cast, they're relatively soft, solid media in liquid at high pressure can actually be driven into the ally, cleaning won't remove it but when the engine is used and heats up, expansion of the castings releases solid blast media into the oil, to do nasty things to bearings, pump, etc.

Otoh:-

. Soda blasting's only residue is water-soluble; if you have access to a compressor, your "Harbor Fright" sells gun and blasting soda; do it outside, wash away the remains when done.

. Dry-ice basting doesn't leave any residue.


Would need polishing again?


Regret I don't know enough to comment on your tappets questions, but your crankcase photos. at least show good alignment around the holes for the tappet guide blocks?

Nevertheless, most important is whether main and camshaft bearing housings are concentric between the two crankcase castings. Meriden achieved this by bolting crankcase castings together and then machining them together. As castings had to come apart subsequently for engine assembly, to ensure castings machined together were reassembled together, each 'half' was stamped with a code on the lower engine mounting lug (note this isn't the "engine number" as stamped on the drive-side crankcase at the end of assembly)

If your engine's crankcase castings either have different codes or none at all, you might wish to have the aforementioned alignments checked. Any competent machinist can make a couple of shafts to check crank and cam bearings; however, the finished accuracy necessary probably means grinding which could cost you two or three hours. A possible alternative is sending the cases to Coventry Spares (John Healy), who has the shafts to do the check.

Hth.

Regards,

Stuart, thanks for your response. OK, the cases do belong together - I found the code on the engine mounting lug - thanks! On the blasting, I'm still considering whether or not to do this. I know several folks who have this done and apparently the media used is not a concern - as long as one washes the items blasted effectively, several times. This process makes all look quite uniform and clean. Although over time I imagine it would develop the usual patina. Thank you for engine code info.

 

[Dr. Zo]

Tappet oil drillway advice needed.

So I purchased an AERCO big bore kit to replace my aged Routt. On the old Routt there was no exhaust tappet oil feed driveway, and the right side engine case had the oil driveway plugged. Additionally the exhaust tappets in the engine had no machined cut out or oil hole.

The AERCO cylinder has an open, exhaust tappet oil feed drillway. So what is a good way to proceed? Should I open up the right side case driveway, and buy new exhaust tappets with the machined part and oil hole? Has anyone had experience with this kind of situation?

Thanks!