 Fixing poor leakdown, Cyl 1 leaks at 50%, rest are cool. |
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| VaccaRabite |
 Oct 24 2007, 07:00 AM
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En Garde!  Group: Admin Posts: 13,465 Joined: 15-December 03 From: Dallastown, PA Member No.: 1,435 Region Association: MidAtlantic Region  |
So, at the Sterling meet I did a leakdown test on my motor, and found a problem with Cylinder 1. 45% leakdown, but 120 lbs of compression. Was tempted just to let sleeping dogs lie, but pulled the head off.
What was going on was clear as soon as we did that, the head was not totaly sealed to the cylinder, off by a very small amount. Instead of having the head recut, I decided to try and lap the two of them together. So, last night I hand lapped them, using ground graphite to check for even contact. I got good contact after the third round of hand lapping (lap, clean, check). Now I need to get the jug back on the block. I have a ring compressor on the piston, but I can't ficgure out how to get the head back on. Do I have to take the piston head off the rod? If so, how do I get it off. It looks like that tis a spring keeper that needs to be removed. Is there anyhting on the rod the needs to be loosened before I can pull the pin out to remove the piston head? Obviously, if there is a trick to getting the jug back on without pulling off the piston head, I'd like to do that. Zach |
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Posts in this topic
Vacca Rabite Fixing poor leakdown Oct 24 2007, 07:00 AM
Brando DO NOT take off the piston. If you do that then in... Oct 24 2007, 07:24 AM Vacca Rabite Maybe I was not clear.
How do I get the cylinder ... Oct 24 2007, 07:30 AM type47 it may be difficult to install the jugs on to an e... Oct 24 2007, 07:54 AM blitZ You need to take the piston off the rod. Remove t... Oct 24 2007, 07:54 AM geniusanthony Lemme try and work this out in my head. Cylinder 1... Oct 24 2007, 07:58 AM Vacca Rabite Okay, I thought that was what I'd have to do. ... Oct 24 2007, 08:02 AM type47 i reread your first post and i'm sure you know... Oct 24 2007, 08:06 AM geniusanthony Talk about some fast replies eh??
The best non-clu... Oct 24 2007, 08:07 AM
orange914
Talk about some fast replies eh??
The best non-cl... Oct 25 2007, 07:58 PM Dave_Darling We put the cylinders onto the pistons, not the pis... Oct 24 2007, 09:37 AM Cap'n Krusty Well, isn't this confusing? First the questio... Oct 24 2007, 11:11 AM type47
As for installing the cylinder over the piston, ... Oct 24 2007, 11:24 AM Cap'n Krusty
As for installing the cylinder over the piston,... Oct 24 2007, 01:24 PM Elliot Cannon It is sometimes hard to tell if someone is condesc... Oct 24 2007, 02:58 PM KELTY360
geez Cap'n, i always read your very informati... Oct 24 2007, 07:26 PM Vacca Rabite ^^^
If I have to have the head recut, then I do.
... Oct 24 2007, 11:31 AM brer I used to love the book "how to keep your air... Oct 24 2007, 11:38 AM scotty b Cap'n he has done no damage. The blowby was VE... Oct 24 2007, 06:54 PM jimkelly i am pretty sure a type4 don't need no stinkin... Oct 24 2007, 09:01 PM Twystd1 Man..... The Capt. nailed it.
Clayton Oct 25 2007, 09:02 PM jaminM3 In the Jake Assembly video he installs the piston ... Oct 26 2007, 05:29 PM So.Cal.914 I don't think it really matters which way you ... Oct 26 2007, 05:53 PM kwales Done it both ways. You can slide the cylinder ont... Oct 26 2007, 07:36 PM DNHunt I've done it both ways. I find getting the wri... Oct 27 2007, 07:11 AM Vacca Rabite So, here is what I ended up doing.
I took out the... Oct 31 2007, 09:31 AM Jake Raby Typically any leak at the sealing surfaces will ef... Oct 31 2007, 11:10 AM Vacca Rabite
Typically any leak at the sealing surfaces will e... Oct 31 2007, 11:57 AM type47 for the purposes of a quick (not necessarily accur... Oct 31 2007, 01:03 PM Twystd1 yup Oct 31 2007, 08:58 PM DNHunt I think Jake has cases routinely decked now so eve... Nov 1 2007, 11:09 AM Jake Raby Today with most cases being over 30 years old we h... Nov 1 2007, 11:25 AM scotty b Jake the area that was leaking on Zach's engin... Nov 1 2007, 07:50 PM Vacca Rabite Well, tonight I re-leak downed the cylinder and th... Dec 20 2007, 05:09 PM Dr Evil Take the engine to your machinist and have them ch... Dec 20 2007, 06:26 PM Dr Evil OK, I had more than a second to think on this and ... Dec 20 2007, 08:02 PM Vacca Rabite No gaskets at the base of either of the cylinders.... Dec 20 2007, 10:36 PM Dr Evil They make special tools for this....but you can ju... Dec 21 2007, 12:07 AM type11969 Drop a straight edge across the cylinder tops too.... Dec 21 2007, 06:44 AM Vacca Rabite Well I had time to work tonight, so I did more tes... Dec 27 2007, 12:15 AM Jake Raby Use an open flame around the sealing surface to ch... Dec 27 2007, 09:58 AM Vacca Rabite I got the engine from Evan Thompson. I havn't... Dec 27 2007, 07:30 PM Vacca Rabite I pulled the heads, and then made some spacers out... Dec 27 2007, 07:31 PM Borderline
I pulled the heads, and then made some spacers ou... Dec 29 2007, 12:22 PM davep
I put a level with a good straight edge across th... Dec 31 2007, 04:19 PM Vacca Rabite Okay, so I measured deck height today with Josh... Dec 29 2007, 12:08 AM orange914
Okay, so I measured deck height today with Josh... Dec 29 2007, 12:10 AM degreeoff Just dont forget to swap the heads and check to se... Dec 29 2007, 07:18 AM Dr Evil I agree that you need to have the cylinder lengths... Dec 29 2007, 12:33 PM Vacca Rabite Bzzt. I'm wrong again.
Now I think that the h... Dec 30 2007, 10:03 PM Jake Raby You cannot shim just one cylinder! Both cylind... Dec 30 2007, 10:14 PM Vacca Rabite I'm going to try this - not now but tomorrow m... Dec 30 2007, 10:37 PM Jake Raby Dry.. The Sharpie will work if you apply it heavil... Dec 30 2007, 10:46 PM scotty b Zach a shim isn't the answer. Remember when we... Dec 31 2007, 03:30 PM Jake Raby Are these Chinese cylinders?? Dec 31 2007, 05:03 PM Brando Did you ever check your piston rings?
I've se... Dec 31 2007, 05:06 PM scotty b
Did you ever check your piston rings?
I've s... Dec 31 2007, 05:18 PM Vacca Rabite My rings are golden. As on good, not gold colored... Dec 31 2007, 06:58 PM scotty b NOW we're getting somewhere !! :troph... Dec 31 2007, 07:04 PM davep Well, it appears most of your problem was the extr... Dec 31 2007, 07:54 PM Jake Raby
No!!
Thats half assed!
You MUST hav... Dec 31 2007, 08:27 PM Vacca Rabite Well, I just put the cylinders back on, put the he... Dec 31 2007, 09:36 PM Brando Glad you're on the right path now :) Things wi... Jan 2 2008, 01:31 AM Jake Raby Welcome to the world of mechanical manipulation.
... Dec 31 2007, 10:04 PM Vacca Rabite Do I need to replace the cylinder? If you added u... Dec 31 2007, 10:31 PM Dr Evil New cylinder time :( I am impressed with your pers... Jan 1 2008, 11:10 AM degreeoff Hey Zach,
Remember I told you I have that case la... Jan 1 2008, 11:16 AM root Zach,
Real sorry about the cylinder drop! Shi... Jan 1 2008, 11:38 AM Jake Raby Yep, that cylinder is toast.. Jan 1 2008, 12:59 PM scotty b :( Damn........ Jan 1 2008, 08:06 PM Dr Evil I got him fixed up. I gave him 2 cylinders (so if ... Jan 1 2008, 08:16 PM scotty b Damn cool :headbanger: Jan 1 2008, 08:34 PM Vacca Rabite Yup, got some used jugs from Mike, and a dial guag... Jan 2 2008, 09:52 AM r_towle Bring the piston that you will be using in that cy... Jan 2 2008, 10:19 AM Vacca Rabite THANKS!
I did not know that.
Zach Jan 2 2008, 10:30 AM davep Perhaps Jake will chime in on this for the definit... Jan 2 2008, 03:27 PM scotty b Probably would be a god idea to have BOTH of the c... Jan 2 2008, 06:49 PM Twystd1 You will also need to know what plateau finish to ... Jan 2 2008, 08:53 PM Vacca Rabite I just dropped Cyl 1&2 and piston 1 off at Air... Jan 3 2008, 03:37 PM Vacca Rabite I am impatient. I want to get back to work on my ... Jan 4 2008, 09:06 PM orange914
I am impatient. I want to get back to work on my... Jan 5 2008, 12:46 AM Vacca Rabite The leak is at the head, no question.
Okay, a que... Jan 5 2008, 10:15 AM DNHunt Patience Grasshoppa
Keep soaking and heating and ... Jan 5 2008, 11:55 AM type11969 Get a good penetrant like PB Blaster or Kroil, the... Jan 5 2008, 01:02 PM Twystd1 I tried the liquid oxygen trick ONCE.
The stud sn... Jan 5 2008, 02:37 PM type11969 Thats good to know! Jan 5 2008, 02:54 PM Dr Evil Why are you removing the head studs? Jan 7 2008, 08:25 AM type11969 decking the case I would imagine Jan 7 2008, 08:33 AM Vacca Rabite Mainly I was removing the head studs so I could ge... Jan 7 2008, 08:38 AM Dr Evil I could be wrong, but I didnt think that was neces... Jan 7 2008, 10:00 AM type11969 If you've gone to the trouble of pulling the s... Jan 7 2008, 10:15 AM Brando When heating, apply flame to the stud not the case... Jan 7 2008, 03:12 PM Dr Evil Why would you want to expand the stud and not the ... Jan 7 2008, 04:25 PM Twystd1 Just keep tapping the stud. And tweaking it every ... Jan 7 2008, 04:47 PM Vacca Rabite I am spraying the stud with PB Blaster and tapping... Jan 7 2008, 06:27 PM orange914
I am spraying the stud with PB Blaster and tappin... Jan 7 2008, 11:45 PM Spoke Any way to get an impact wrench on it? It would se... Jan 7 2008, 09:42 PM type11969
Any way to get an impact wrench on it? It would s... Jan 8 2008, 06:54 AM Vacca Rabite What is the best way to split the case? I have al... Jan 8 2008, 08:55 AM type47
What is the best way to split the case?
this m... Jan 8 2008, 10:49 AM  |
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