Topic: Henry Abe 900cc big bore pain in the ass

[BPellerine]

Hey PeWe, you're saying that going from my 67 HA to 68mm is not going to be possible without re-sleeving? I may need to do this as 1 of 4 liners is showing vertical scratching above and beyond normal break-in wear. 

I think it would be best to check with cycle x,I have a few of these pistons including a nos set,and no matter where I measured them they were no more than 67mm,890 was called 900 back in the day by some.bill

[scottly]

Yeah. Heads still on and the pic is not so great with the cheap bore scope. Of course it's on my laptop and it's packed away for Bonneville tomorrow. Maybe I can figure out 1. how to locate it on my laptop 2. post it if I can find it next day or so once settled in at The Salt. 

Won't wonders ever cease LOL  Fresh cross hatch 135 miles.

About time you learned how to attach a pic!!!  Are the wear marks on the side of the bore? Looks to be about the width of a piston pin...

[Rio83]

Scottly is right. Maybe a missing lock ring


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[PeWe]

Hey PeWe, you're saying that going from my 67 HA to 68mm is not going to be possible without re-sleeving? I may need to do this as 1 of 4 liners is showing vertical scratching above and beyond normal break-in wear. 

Hi,
No, if you have 67mm pistons, you can bore more and use newer 67.5 mm pistons. CycleX call their 900 pistons (67.5mm) for 915cc. Even Satanic mechanic made a mistake calculating wrong writing 915cc  when piston is 67.5 mm. Dynoman has 67.5mm too

The cylinder that followed my HA pistons had 67.5mm bores. Pic show 67.45 with a caliper that is not giving an accurate value. Bore caliper needed.

[Jerry Rxman Griffin aka MuthaF'er]

Well that's good news Pewe. The 915 kit is my next option but I was thinking it was +1 or 68mm over my 67mm vs + 0.5 at 67.5.

I was wondering about that pin too but thought that perhaps since there is a squared pin on the end (perpendicular) in a round cylinder that maybe it wouldn't show the entire width/diameter of the pin?? I kinda expected to find a mess in the oil pan but didn't and no circlip either unless I just missed it. I really wasn't looking for that in the oil. Only a top end tear down will reveal the mystery. I may have time coming up after Bonneville.

Some good thoughts/ideas guys. Thanks. 

Rio, sounds like you have a good handle on yours. If you need the Total Seal part numbers let me know. I didn't want to use the one piece oil ring. My HA pistons are the other style. Guess some call them slipper pistons without the full skirt.

[Rio83]

Well that's good news Pewe. The 915 kit is my next option but I was thinking it was +1 or 68mm over my 67mm vs + 0.5 at 67.5.

I was wondering about that pin too but thought that perhaps since there is a squared pin on the end (perpendicular) in a round cylinder that maybe it wouldn't show the entire width/diameter of the pin?? I kinda expected to find a mess in the oil pan but didn't and no circlip either unless I just missed it. I really wasn't looking for that in the oil. Only a top end tear down will reveal the mystery. I may have time coming up after Bonneville.

Some good thoughts/ideas guys. Thanks. 

Rio, sounds like you have a good handle on yours. If you need the Total Seal part numbers let me know. I didn't want to use the one piece oil ring. My HA pistons are the other style. Guess some call them slipper pistons without the full skirt.

Thank you Jerry. I got all the numbers from Total Seal. Got a quote from them in case I have to buy new rings. But looks like everything is good so I guess I put it all back together


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[PeWe]

Well that's good news Pewe. The 915 kit is my next option but I was thinking it was +1 or 68mm over my 67mm vs + 0.5 at 67.5.

I was wondering about that pin too but thought that perhaps since there is a squared pin on the end (perpendicular) in a round cylinder that maybe it wouldn't show the entire width/diameter of the pin?? I kinda expected to find a mess in the oil pan but didn't and no circlip either unless I just missed it. I really wasn't looking for that in the oil. Only a top end tear down will reveal the mystery. I may have time coming up after Bonneville.

Some good thoughts/ideas guys. Thanks. 

Rio, sounds like you have a good handle on yours. If you need the Total Seal part numbers let me know. I didn't want to use the one piece oil ring. My HA pistons are the other style. Guess some call them slipper pistons without the full skirt.

Thank you Jerry. I got all the numbers from Total Seal. Got a quote from them in case I have to buy new rings. But looks like everything is good so I guess I put it all back together


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Sure iit will be correct rings? Verify piston size with the, 67.5 mm as the bore.
This has been up before in the "High Performance and Racing Forum"  people order rings for their old HA pistons. In that case the 888cc pistons, 67.0mm, not 67.5 as I have.
I needed one oil ring for one piston.  I gave those up.
Later another 900 kit with Wiseco pistons that initially came from CycleX.  I continued to upgrade to JMR billet block and more cc

[Rio83]

Well that's good news Pewe. The 915 kit is my next option but I was thinking it was +1 or 68mm over my 67mm vs + 0.5 at 67.5.

I was wondering about that pin too but thought that perhaps since there is a squared pin on the end (perpendicular) in a round cylinder that maybe it wouldn't show the entire width/diameter of the pin?? I kinda expected to find a mess in the oil pan but didn't and no circlip either unless I just missed it. I really wasn't looking for that in the oil. Only a top end tear down will reveal the mystery. I may have time coming up after Bonneville.

Some good thoughts/ideas guys. Thanks. 

Rio, sounds like you have a good handle on yours. If you need the Total Seal part numbers let me know. I didn't want to use the one piece oil ring. My HA pistons are the other style. Guess some call them slipper pistons without the full skirt.

Thank you Jerry. I got all the numbers from Total Seal. Got a quote from them in case I have to buy new rings. But looks like everything is good so I guess I put it all back together


Sent from my iPhone using Tapatalk

Sure iit will be correct rings? Verify piston size with the, 67.5 mm as the bore.
This has been up before in the "High Performance and Racing Forum"  people order rings for their old HA pistons. In that case the 888cc pistons, 67.0mm, not 67.5 as I have.
I needed one oil ring for one piston.  I gave those up.
Later another 900 kit with Wiseco pistons that initially came from CycleX.  I continued to upgrade to JMR billet block and more cc

Do you mean the ones from Total Seal or the ones I already have?


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[PeWe]

Well that's good news Pewe. The 915 kit is my next option but I was thinking it was +1 or 68mm over my 67mm vs + 0.5 at 67.5.

I was wondering about that pin too but thought that perhaps since there is a squared pin on the end (perpendicular) in a round cylinder that maybe it wouldn't show the entire width/diameter of the pin?? I kinda expected to find a mess in the oil pan but didn't and no circlip either unless I just missed it. I really wasn't looking for that in the oil. Only a top end tear down will reveal the mystery. I may have time coming up after Bonneville.

Some good thoughts/ideas guys. Thanks. 

Rio, sounds like you have a good handle on yours. If you need the Total Seal part numbers let me know. I didn't want to use the one piece oil ring. My HA pistons are the other style. Guess some call them slipper pistons without the full skirt.

Thank you Jerry. I got all the numbers from Total Seal. Got a quote from them in case I have to buy new rings. But looks like everything is good so I guess I put it all back together


Sent from my iPhone using Tapatalk

Sure iit will be correct rings? Verify piston size with the, 67.5 mm as the bore.
This has been up before in the "High Performance and Racing Forum"  people order rings for their old HA pistons. In that case the 888cc pistons, 67.0mm, not 67.5 as I have.
I needed one oil ring for one piston.  I gave those up.
Later another 900 kit with Wiseco pistons that initially came from CycleX.  I continued to upgrade to JMR billet block and more cc

Do you mean the ones from Total Seal or the ones I already have?


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From Total Seal if you intend to order new rings.
Important to verify with actual piston size, bore diam. CC numbers can be mixed up or very close.

[PeWe]

One more confusing detail.
Rings to HA 900 kit that must be to the 67.5mm bore. But seller say 67mm. It's a must to ask seller to check once more
https://www.ebay.com/itm/NOS-Honda-CB750-Henry-Abe-900CC-Big-Bore-Piston-Rings-Set-CB-750/302833255366?hash=item468244c3c6:g:0RIAAOSw42JZCoLR

I should not be that sure if I had not have measured an old HA 900cc kit I bought too quick with bores not good and 1 ring missing. I could trade the old cylinder to other parts.

[Rio83]

One more confusing detail.
Rings to HA 900 kit that must be to the 67.5mm bore. But seller say 67mm. It's a must to ask seller to check once more
https://www.ebay.com/itm/NOS-Honda-CB750-Henry-Abe-900CC-Big-Bore-Piston-Rings-Set-CB-750/302833255366?hash=item468244c3c6:g:0RIAAOSw42JZCoLR

I should not be that sure if I had not have measured an old HA 900cc kit I bought too quick with bores not good and 1 ring missing. I could trade the old cylinder to other parts.

I contacted this seller and he claimed he didnt have a precise measuring tool


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[Rio83]

Got this mail from Wiseco.




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[PeWe]

That kit is not for CB750 SOHC  1969-76
That's for twin cam 4 valve head later models. CB900 has 1.5mm longer rods than CB750 SOHC, pistons probably lower.

[Rio83]

That kit is not for CB750 SOHC  1969-76
That's for twin cam 4 valve head later models. CB900 has 1.5mm longer rods than CB750 SOHC, pistons probably lower.

Weird she sugested this kit when it dosent fit


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[BPellerine]

maybe the .50 on the piston points to 67.5,none of mine have that,all are 67mm.bill

[Rio83]

maybe the .50 on the piston points to 67.5,none of mine have that,all are 67mm.bill

Guess so


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