HarleyTechTalk

.... and 1/4" studs and 12 point flange nuts in the 2 dowel holes for the cam plate are a good idea if not done yet too.

And just because you can, flush/clean the oil bag & lines, again; you want this project to give a you as many decades of satisfaction, as it gave you moments of frustration.

Quote from: Adam76 on December 30, 2021, 07:53:25 PMEngine cases are back together. Just waiting on my pistons and cylinders to arrive (Thanks Don) and I'm just about there.

Have a good new year, and thanks for all the help and advice you have given me on this build.

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Really glad to see you doing the bulk of this yourself.

Quote from: rigidthumper on December 31, 2021, 03:54:44 AMAnd just because you can, flush/clean the oil bag & lines, again; you want this project to give a you as many decades of satisfaction, as it gave you moments of frustration.

Thanks, yes flushed oil tank and oil lines many times!!! I'm not taking any chances now with this build... 
I want it to run well, and for a very long time.

Quote from: FSG on December 30, 2021, 09:06:58 PMa few things to do while you wait ..

take 50 thou of the compensator nut if it's not been shortened already

open up the top ends of the PR Tubes to 5/8" if you have that drill bit, 15 or 15.5 mm if it

Thanks FSG.
When opening up the top of the PRs, how do you prevent metal shavings going into the body of the PR tube?

Just got my heads out to clean up the fouled exhaust port, and noticed a few minor scratches on the machined surface.... I know it's just a picture, but do you think I need to get the heads milled again to clean them up?
Hopefully not, because I'm already at 83cc and pushing 10.3  (9.6 corrected) compression with my .030 mls gaskets and CR575 cams. 

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Doesn't look deep enough to bother with. Issues arise if there's a gouge that connects the combustion chamber with the outside world, and I don't see anything like that in your pics.
I use a small piece of sandpaper to smooth the opening after boring the pushrod tube inners, and a bottle brush with soapy water to clean the pushrod tube tops after boring them. Rinse well, inspect, and reassemble.

Do not mill them. Use a fine whetstone 600 grit and WD40 to take care of minors like that.

Quote from: Adam76 on January 03, 2022, 01:44:03 AM

Quote from: FSG on December 30, 2021, 09:06:58 PMa few things to do while you wait ..

take 50 thou of the compensator nut if it's not been shortened already

open up the top ends of the PR Tubes to 5/8" if you have that drill bit, 15 or 15.5 mm if it

Thanks FSG.
When opening up the top of the PRs, how do you prevent metal shavings going into the body of the PR tube?

I'm not FSG, but that can't be helped. You just wash them out before using them.

Quote from: Ohio HD on January 03, 2022, 08:29:44 AM

Quote from: Adam76 on January 03, 2022, 01:44:03 AM

Quote from: FSG on December 30, 2021, 09:06:58 PMa few things to do while you wait ..

take 50 thou of the compensator nut if it's not been shortened already

open up the top ends of the PR Tubes to 5/8" if you have that drill bit, 15 or 15.5 mm if it

Thanks FSG.
When opening up the top of the PRs, how do you prevent metal shavings going into the body of the PR tube?

I'm not FSG, but that can't be helped. You just wash them out before using them.

I think FSG was talking about drilling out the top of the top section of pushrod tube.  Drill the inside to 5/8" to a depth of about 1 1/2'.  DO NOT do it by hand.  It is best done on a lathe.  Any machine shop can do all 4 tubes in a few minutes if you don't have a lathe or a friend to help you. 

OK thanks.... I get it now. PR cover tube (not the top oil opening of the actual PR) 

Yes sir.

It's not mandatory to do this. It just helps give additional clearance to the pushrod.

I have the bottom end back in the frame all bolted up and ready for the top end. Just waiting on some .040" head gaskets (Thanks Don) because with the .030" and the piston's dome volume of 6.7 has pushed my actual corrected compression to 9.8 and my ccp to 213.
With the .040" HG I'm at 9.64 corrected and 208 ccp -- still not sure that's going to be ok especially with the bike being carbed not EFI. It will be getting dyno tuned though and it has DTT ignition module.

Any tips / tricks on slipping the cylinders down over the pistons during assembly? What's the best method? Ring compressor tool?

Thanks


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You can use ring compressors as long as they will slip off the piston and through between the studs.  You can also put a couple of dowels with some gas line over them under the pistons and slide the barrels down, then use your finger tips and a popsicle stick.  Squeeze the rings together and push them into the ring grooves with the help of the popsicle stick until the barrel drops.  Do one ring at a time.  It's not that hard and you get good control of the ring gap position.

Others may suggest placing the piston and rings into the bottom of the barrel and leave the pin hole exposed.  Slide the barrel on and slip the pin and clip in.  A little persnickety and there's a risk of losing the clip into the bottom end. 

Quote from: Adam76 on January 07, 2022, 06:49:47 PMI have the bottom end back in the frame all bolted up and ready for the top end. Just waiting on some .040" head gaskets (Thanks Don) because with the .030" and the piston's dome volume of 6.7 has pushed my actual corrected compression to 9.8 and my ccp to 213.
With the .040" HG I'm at 9.62 corrected and 205 ccp -- still not sure that's going to be ok especially with the bike being carbed not EFI. It will be getting dyno tuned though and it has DTT ignition module.

Any tips / tricks on slipping the cylinders down over the pistons during assembly? What's the best method? Ring compressor tool?

Thanks

I'd be a little concerned about that compression with a carb. A lot depends on how good he can tune it, and what your riding style is. It won't tolerate any lugging.

What cams are you running?

Are you using base gaskets?

Quote from: kd on January 07, 2022, 06:59:11 PMYou can use ring compressors as long as they will slip off the piston and through between the studs.  You can also put a couple of dowels with some gas line over them under the pistons and slide the barrels down, then use your finger tips and a popsicle stick.  Squeeze the rings together and push them into the ring grooves with the help of the popsicle stick until the barrel drops.  Do one ring at a time.  It's not that hard and you get good control of the ring gap position.

Others may suggest placing the piston and rings into the bottom of the barrel and leave the pin hole exposed.  Slide the barrel on and slip the pin and clip in.  A little persnickety and there's a risk of losing the clip into the bottom end. 

Quote from: Ohio HD on January 07, 2022, 07:05:13 PM

Quote from: Adam76 on January 07, 2022, 06:49:47 PMI have the bottom end back in the frame all bolted up and ready for the top end. Just waiting on some .040" head gaskets (Thanks Don) because with the .030" and the piston's dome volume of 6.7 has pushed my actual corrected compression to 9.8 and my ccp to 213.
With the .040" HG I'm at 9.62 corrected and 205 ccp -- still not sure that's going to be ok especially with the bike being carbed not EFI. It will be getting dyno tuned though and it has DTT ignition module.

Any tips / tricks on slipping the cylinders down over the pistons during assembly? What's the best method? Ring compressor tool?

Thanks

I'd be a little concerned about that compression with a carb. A lot depends on how good he can tune it, and what your riding style is. It won't tolerate any lugging.

What cams are you running?

Yeah, I'm a little concerned and may have to get the piston dome milled down a bit... CR575 cams, they are brand new so I want to keep them -- otherwise I'd be throwing in a set of S&S 570s

Quote from: kd on January 07, 2022, 07:10:27 PMAre you using base gaskets?

Not yet - just have the base o-rings.

Can you buy thicker cyl base gaskets? Would that help?

Quote from: Adam76 on January 07, 2022, 07:14:40 PMYeah, I'm a little concerned and may have to get the piston dome milled down a bit... CR575 cams, they are brand new so I want to keep them -- otherwise I'd be throwing in a set of S&S 570s

Yeah, I would do that. Or have someone slightly open the combustion chambers in the head. The piston is hard to know what to take off unless someone has done it and measured them before and after. Also if a head is opened up a little too much, you can machine the head gasket surface slightly to bring it back to a smaller chamber. Pistons, once they're machined, they're machined, done.

IMO the CR575's are worth the effort.  They perform early, well, and actually like 10.5:1 compression.

The reason I asked about base gaskets is you can get a bit back there also.  If you had time you can call Cometic and they will make you a set in any size material they have.  It seems .020 and .010 are readily available (and maybe others).  They can probably Express Post them to you.

Quote from: Ohio HD on January 07, 2022, 07:18:08 PM

Quote from: Adam76 on January 07, 2022, 07:14:40 PMYeah, I'm a little concerned and may have to get the piston dome milled down a bit... CR575 cams, they are brand new so I want to keep them -- otherwise I'd be throwing in a set of S&S 570s

Yeah, I would do that. Or have someone slightly open the combustion chambers in the head. The piston is hard to know what to take off unless someone has done it and measured them before and after. Also if a head is opened up a little too much, you can machine the head gasket surface slightly to bring it back to a smaller chamber. Pistons, once they're machined, they're machined, done.

New cams here for me is going to set me back another AUS $600... not sure that's the best way forward? Not sure how much it would be to open up the heads a little. Everything harley costs much more downunder.

Quote from: kd on January 07, 2022, 07:20:37 PMIMO the CR575's are worth the effort.  They perform early, well, and actually like 10.5:1 compression.

The reason I asked about base gaskets is you can get a bit back there also.  If you had time you can call Cometic and they will make you a set in any size material they have.  It seems .020 and .010 are readily available (and maybe others).  They can probably Express Post them to you.

Thanks kd.... 10.5 compression is the static compression right? My heads are cc'd at 83cc and corrected compression is the important one, right? So are you saying 9.62 corrected is OK??

Quote from: Adam76 on January 07, 2022, 07:21:44 PMNew cams here for me is going to set me back another AUS $600... not sure that's the best way forward? Not sure how much it would be to open up the heads a little. Everything harley costs much more downunder.

What motor specs are you using to calculate the compression? What piston CC, head CC, etc.

Quote from: Ohio HD on January 07, 2022, 07:26:35 PM

Quote from: Adam76 on January 07, 2022, 07:21:44 PMNew cams here for me is going to set me back another AUS $600... not sure that's the best way forward? Not sure how much it would be to open up the heads a little. Everything harley costs much more downunder.

What motor specs are you using to calculate the compression? What piston CC, head CC, etc.

I'm putting in all my specs on both the BigBoyz calculator and the Hammer Performance calculator. Both give me a similar result.

What are the piston CC's?