I just got my head back from the machine shop. Does anyone know the minimum head height before I have to use a shim, or know where I can get that info? The shop said a new head is 4.26 and mine is 4.244. So I'm .016 shy. Is that close enough?
many thanks,Justin
L20B Cylinder Head Height Spec
-
justinae
- Posts: 62
- Joined: Sat Oct 17, 2009 5:57 am
- Car: 1980 Datsun 720 King Cab
- Location: Portland, OR
Re: (Charlie69)
Yeah I hope that's cool. I just really need to wrap up this project as it's a work truck and not just for fun.
I am still a bit confused on the whole sprocket, #1, #2 position thing. Not sure why I can't get my head wrapped around it.
I am still a bit confused on the whole sprocket, #1, #2 position thing. Not sure why I can't get my head wrapped around it.
No Problem. I am glad you did.
The way I understand the 1,2, & 3 is first it changes your timing advanced or retarded. Second and I am not sure about this but it makes sense, when the timing chain stretches it gets loose and chnges the timing so when the timing chain is stretched you can move the sprocket up one hole to take up for the out of timing from the stretch.
When Datsun assembled the motors originally the # 2 position was used. This # 2 position represents the center point of the 3 holes. I remember somewhere reading that each equalled 4 degrees in timing so # 2 positon being the one that was zero degrees which allowed for 4 degrees advanced (#3) or 4 degrees retarded (#1). This would allow you to make a little adjustment to help time the distibutor with the timing marks or also a non stock cam.
The way I understand the 1,2, & 3 is first it changes your timing advanced or retarded. Second and I am not sure about this but it makes sense, when the timing chain stretches it gets loose and chnges the timing so when the timing chain is stretched you can move the sprocket up one hole to take up for the out of timing from the stretch.
When Datsun assembled the motors originally the # 2 position was used. This # 2 position represents the center point of the 3 holes. I remember somewhere reading that each equalled 4 degrees in timing so # 2 positon being the one that was zero degrees which allowed for 4 degrees advanced (#3) or 4 degrees retarded (#1). This would allow you to make a little adjustment to help time the distibutor with the timing marks or also a non stock cam.
Also I beleive the Hainz is one of the founders of Ratsun.
His video has helped many people including me.
I remember working on Datsun's before the internet and how it was we got information from dealerships, car clubs, magazines, and mostly the libraries. Libraries used to have a trmendous amount of books on car care in the 60s & 70s.
I really enjoy the internet for the reasons of making information so easily shared.
Keep us posted on your truck and how you are doing.
A little note, I feel it was OK for me to post you a link to a post of mine on Ratsun rather than tell you to go look on Ratsun or any other site. this is just in my thinking more appropriate. Correct me please moderators if I am wrong.
I just do not feel out of respect for NICO that it is proper to refer someone to another website.
His video has helped many people including me.
I remember working on Datsun's before the internet and how it was we got information from dealerships, car clubs, magazines, and mostly the libraries. Libraries used to have a trmendous amount of books on car care in the 60s & 70s.
I really enjoy the internet for the reasons of making information so easily shared.
Keep us posted on your truck and how you are doing.
A little note, I feel it was OK for me to post you a link to a post of mine on Ratsun rather than tell you to go look on Ratsun or any other site. this is just in my thinking more appropriate. Correct me please moderators if I am wrong.
I just do not feel out of respect for NICO that it is proper to refer someone to another website.
-
justinae
- Posts: 62
- Joined: Sat Oct 17, 2009 5:57 am
- Car: 1980 Datsun 720 King Cab
- Location: Portland, OR
Re: (Charlie69)
Hi Charlie. Good to see you online again.
Man the whole timing thing is really kicking my butt. Let me see if I can think out loud.
Before I took the chain off I made a mark on the chain and the sprocket. At that time the dowel on the cam was in the 12:00 position, and the sprocket was set to the #1. So I understand the whole concept of moving the sprocket to the number two position, but what I don't understand is if I just simply put it on in that position and the put the chain on as is. Or do I move the #1 piston out of TDC until I can put the sprocket on so that it is in the #2 position with the dowel at 12:00 and still match up the marks I made.
Does that make ANY sense?
And in regards to the forums. I'm not a moderator so I can't say, but I hope it's not a sense of competition but just a bunch of folks who like shootin the breeze about Datsuns and helping guys like me out. But that's just me.
thanks again, you've been a huge help.
Man the whole timing thing is really kicking my butt. Let me see if I can think out loud.
Before I took the chain off I made a mark on the chain and the sprocket. At that time the dowel on the cam was in the 12:00 position, and the sprocket was set to the #1. So I understand the whole concept of moving the sprocket to the number two position, but what I don't understand is if I just simply put it on in that position and the put the chain on as is. Or do I move the #1 piston out of TDC until I can put the sprocket on so that it is in the #2 position with the dowel at 12:00 and still match up the marks I made.
Does that make ANY sense?
And in regards to the forums. I'm not a moderator so I can't say, but I hope it's not a sense of competition but just a bunch of folks who like shootin the breeze about Datsuns and helping guys like me out. But that's just me.
thanks again, you've been a huge help.
Re: (justinae)
If you are changing the cam sprocket position relative to the camshaft, then that is the change you are going for, and you would line the marks you made on the chain and sprocket back up, I think....
I don't know what to tell you about the competition thing, we are all against each other in the end. I tried to write something that seemed better, but it was drivel. That said, I do get a personal kick out of helping others out, for some reason. I remember changing a head gasket on a 2.0 cavalier, the frustration, the long hours, the inablility to scrub all the grease off my hands. Turned out the car only needed the catalytic converter cut off and the head gasket was never even bad. That was 10 years ago.
I don't know what to tell you about the competition thing, we are all against each other in the end. I tried to write something that seemed better, but it was drivel. That said, I do get a personal kick out of helping others out, for some reason. I remember changing a head gasket on a 2.0 cavalier, the frustration, the long hours, the inablility to scrub all the grease off my hands. Turned out the car only needed the catalytic converter cut off and the head gasket was never even bad. That was 10 years ago.
-
justinae
- Posts: 62
- Joined: Sat Oct 17, 2009 5:57 am
- Car: 1980 Datsun 720 King Cab
- Location: Portland, OR
Re: (seang)
Sean you read my mind man. I've been thinking this whole time "I wonder if the head gasket never even blew?" But I've really enjoyed the process and like you, I really enjoy learning from others who have gone before me. When it's an area that I have experience in, then I get to be the one to help.
Regarding the cam. I seriously woke up several times last night playing it out in my head. I just need to get up to the garage. I'm going to install it back to exactly the way it was, take pictures, then install it the way I THINK everyone is saying, then take pictures, and report back.
thanks again,J
Regarding the cam. I seriously woke up several times last night playing it out in my head. I just need to get up to the garage. I'm going to install it back to exactly the way it was, take pictures, then install it the way I THINK everyone is saying, then take pictures, and report back.
thanks again,J
Justin,
From your first few posts and pictures your head gasket was blown.
Put the chain back the way it came off. start it use a timing light and time it. If the distributor does not turn far enough to bring the timing marks in line (Timed) then you need to change the cam sprocket to the #2 position.
From your first few posts and pictures your head gasket was blown.
Put the chain back the way it came off. start it use a timing light and time it. If the distributor does not turn far enough to bring the timing marks in line (Timed) then you need to change the cam sprocket to the #2 position.
-
justinae
- Posts: 62
- Joined: Sat Oct 17, 2009 5:57 am
- Car: 1980 Datsun 720 King Cab
- Location: Portland, OR
Re: (Charlie69)
Stupid question alert.
What is a timing light?
Can I hook up everything and just leave the valve cover off and still start it? After adding coolant of course. Won't oil go everywhere?
What is a timing light?
Can I hook up everything and just leave the valve cover off and still start it? After adding coolant of course. Won't oil go everywhere?
Re: (justinae)
Google "timing light."
Yes, oil will get flung off the timing chain if you start it without the valve cover.
Yes, oil will get flung off the timing chain if you start it without the valve cover.
Here is a phoenix craigslist add for a timing light
http://phoenix.craigslist.org/....html
Here is a video that should help.
http://www.youtube.com/watch?v=UYGU7mTwsZc
http://phoenix.craigslist.org/....html
Here is a video that should help.
http://www.youtube.com/watch?v=UYGU7mTwsZc
-
justinae
- Posts: 62
- Joined: Sat Oct 17, 2009 5:57 am
- Car: 1980 Datsun 720 King Cab
- Location: Portland, OR
Re: (Charlie69)
Dude that video was cool. What an genius product. Thanks.
Maybe I should post this on the other thread, but do you have any ideas about why I would be having a hard time getting the chain back on? It's almost like it's not as long as it was before. Can the tensioner put too much tension when the chain is originally pulled off?
I'm curious, what made you originally get into your engine? Did you find it pretty easy?
Thanks.J
Maybe I should post this on the other thread, but do you have any ideas about why I would be having a hard time getting the chain back on? It's almost like it's not as long as it was before. Can the tensioner put too much tension when the chain is originally pulled off?
I'm curious, what made you originally get into your engine? Did you find it pretty easy?
Thanks.J
Re: (justinae)
Usually if it is that hard to put on then the tensioner has probably come out too far when you pulled the cam gear putting the chian in a bind keeping you from getting the cam gear& chain in place. If this is the case then you will have to pull the timing cover.
If you want to time to the # 2 spot on the cam gear you leave the motor top dead center and place the cam gear in the chain so that the cam dowel lines up with the # 2 hole in the cam gear. thus timed to the # 2 cam hole.
If you want to time to the # 2 spot on the cam gear you leave the motor top dead center and place the cam gear in the chain so that the cam dowel lines up with the # 2 hole in the cam gear. thus timed to the # 2 cam hole.
Find Your Forum!