Author |
Message |
dedhammike Samba Member
Joined: March 19, 2013 Posts: 21 Location: Dedham Maine
|
Posted: Wed May 17, 2017 8:28 pm Post subject: Top of cylinders in plane?? |
|
|
Building a 2 liter type 4 engine for my bus. New crank, cam rods pistons/cylinders, heads. While checking my deck to figure compression ratio, and having the cylinders clamped down on the corners, I ran a straight edge across the top of the cylinders. On 3/4 side, I had less than .0015 gap on one edge of a cylinder. On 1/2 side, I had about .003 gap on one edge. I pulled the pistons and cylinders off and tried to ran a straight edge across, but it was too long to clear. Is this a common issue with type 4 blocks or am I looking too far. Just want my heads to seal good. I considered pulling the head studs and putting some valve lapping compound under the cylinders to try to level it out, then adjusting with my base shims.
Any advise is welcome. Thanks |
|
Back to top |
|
|
busdaddy Samba Member
Joined: February 12, 2004 Posts: 51125 Location: Surrey B.C. Canada, but thinking of Ukraine
|
Posted: Wed May 17, 2017 10:10 pm Post subject: Re: Top of cylinders in plane?? |
|
|
Measure the length of the barrels from lower sealing surfaces to the uppers, Iv'e seen more than one set that required some lathe work to even up. _________________ Rust NEVER sleeps and stock never goes out of style.
Please don't PM technical questions, ask your problem in public so everyone can play along. If you think it's too stupid post it here
Stop dead photo links! Post your photos to The Samba Gallery!
Слава Україні! |
|
Back to top |
|
|
dedhammike Samba Member
Joined: March 19, 2013 Posts: 21 Location: Dedham Maine
|
Posted: Thu May 18, 2017 6:23 pm Post subject: Re: Top of cylinders in plane?? |
|
|
Checked head side of cylinders with feeler gauge and piece of glass underneath. Then checked block side with dial indicator. They came out perfect.
Removed head studs and noticed mating surface on block near flywheel has burr on outer edge. If I put straight edge on inside of burr, everything lines up good on the case.
Plan on trying to lap cylinders into case. If that doesn't do it, I've got a 5" orbital sander to try to flatten out.
Open to other suggestions if anyone else has run into this. Thanks |
|
Back to top |
|
|
busdaddy Samba Member
Joined: February 12, 2004 Posts: 51125 Location: Surrey B.C. Canada, but thinking of Ukraine
|
Posted: Thu May 18, 2017 7:40 pm Post subject: Re: Top of cylinders in plane?? |
|
|
dedhammike wrote: |
...... If that doesn't do it, I've got a 5" orbital sander to try to flatten out. ......... |
Don't take a sander to the case
You can measure the cylinder lips for out od round and flatness all you like, but you need to measure the overall length of the cylinders from the top lip to the step that sits against the case and compare it to the others. _________________ Rust NEVER sleeps and stock never goes out of style.
Please don't PM technical questions, ask your problem in public so everyone can play along. If you think it's too stupid post it here
Stop dead photo links! Post your photos to The Samba Gallery!
Слава Україні! |
|
Back to top |
|
|
dedhammike Samba Member
Joined: March 19, 2013 Posts: 21 Location: Dedham Maine
|
Posted: Thu May 18, 2017 7:44 pm Post subject: Re: Top of cylinders in plane?? |
|
|
I will check them all and compare. Thanks |
|
Back to top |
|
|
Randy in Maine Samba Member
Joined: August 03, 2003 Posts: 34890 Location: The Beach
|
Posted: Fri May 19, 2017 7:20 am Post subject: Re: Top of cylinders in plane?? |
|
|
Normally it is done sort of like this.....
Type 4s on the left, Type 1s on the right. |
|
Back to top |
|
|
HAM Inc Samba Member
Joined: May 09, 2011 Posts: 161 Location: Watkinsville,GA
|
Posted: Fri May 19, 2017 1:48 pm Post subject: Re: Top of cylinders in plane?? |
|
|
Type 4 bus cases warp. I've decked countless cases over the years and have yet to deck one that didn't need it. The spigots lean and sag. #3 is the worst offender. It will sink and lean.
A straight edge won't always tell the tale.
The best method for checking that the jugs on a bank are both on the same plane is to set them in the spigots (without the pistons installed) and lay a piece of glass or blanchard ground plate that's large enough to completely cover the tops of both jugs so you can look for gaps. _________________ Len Hoffman
Hoffman Automotive Machine Inc.
www.hamheads.com |
|
Back to top |
|
|
Wasted youth Samba Member
Joined: July 06, 2012 Posts: 5134 Location: California's Hot and Smoggy Central Valley
|
Posted: Fri May 19, 2017 4:23 pm Post subject: Re: Top of cylinders in plane?? |
|
|
HAM Inc wrote: |
Type 4 bus cases warp. I've decked countless cases over the years and have yet to deck one that didn't need it. The spigots lean and sag. #3 is the worst offender. It will sink and lean.
A straight edge won't always tell the tale.
The best method for checking that the jugs on a bank are both on the same plane is to set them in the spigots (without the pistons installed) and lay a piece of glass or blanchard ground plate that's large enough to completely cover the tops of both jugs so you can look for gaps. |
1) What is the spigot? The part of the case where the cylinder seats?
2) if you lay in the cylinders without first lapping the mating surfaces, would you run the risk of a false measurement?
3) If the cylinders are lapped and seated, then you place the glass to check for gaps, will the fact that the cylinders are not torqued down in the same manner as when measuring for deck height be cause for concern? |
|
Back to top |
|
|
dedhammike Samba Member
Joined: March 19, 2013 Posts: 21 Location: Dedham Maine
|
Posted: Mon May 22, 2017 5:42 am Post subject: Re: Top of cylinders in plane?? |
|
|
Thank you all. Case was definitely warped. Had a second case available that tested fine with cylinders installed. Will save this case and have it decked if needed in future. |
|
Back to top |
|
|
lil-jinx Samba Member
Joined: August 14, 2013 Posts: 1109 Location: New Brunswick,Canada
|
|
Back to top |
|
|
|