L20B U67

[trout104]

I've read so much on this subject that I have confused myself...my question is... I'm going to rebuild my L20B, I have a U67, ported to 39mm intake,32/36 downdraft weber, L16 exhaust, A46 intake, both gasket matched, stock pistons, and stock cam... I live in southern Alberta at a altitude of 3000 ft...How is that going to effect the build. This not a track car, but also not going to be my daily driver either. I would like something that pulls hard that doesn't need to go 200mph. Before Igo any further, I need to get my head wrapped around this...HELP!!!

[banzai510(hainz)]

IM thinking just fine. maybe leaner on the mixtures but just run it and see what happens.

 

to me its a just a L20 with a weber nothing special

[racerx]

or call pierce manifold and see jetting for said altitude

[datzenmike]

3,000 feet has less air so if carb is set to sea level it will be running too rich (probably not enough to kill performance) and wasting gas. Drive it and pull and check the plug color. White clean... tooo lean. Light tan.... just right, brown down to flat black..... too rich.

 

 

First make sure it's not a carb problem and if a carb problem what problem...

 

http://www.webercarbsdirect.com/v/vspfiles/images/Weber%20Trouble%20Shooting%20Guide.pdf

[trout104]

Well if hainz and DatsunMike say it will be OK..IM GOOD TO GO...thanx guys, I have used your knowledge many times. It took me forever to find that head here.

[trout104]

Just hoping it doesn't ping like a modified!

[trout104]

Not modified Mother trucker

[datzenmike]

I've read so much on this subject that I have confused myself...my question is... I'm going to rebuild my L20B, I have a U67, ported to 39mm intake,32/36 downdraft weber, L16 exhaust, A46 intake, both gasket matched, stock pistons, and stock cam... I live in southern Alberta at a altitude of 3000 ft...How is that going to effect the build.

 

Not going to ping, at least no more than any other stock L20B, U67, 32/26 carb engine. The engine is not changed in any way that would induce pinging.

 

Assume the A46 intake is from an L16? It will have smaller ports to match the smaller 210 head ports on an L16. Even if gasket matched to the U67 it's only wider right at the head. Keep eyes open for a '78-'80 W58 intake. It's also water cooled like the A46... (you did drill out the U67 head for the water cooled intake, right? Important to run water cooled/warmed intake so engine runs better over a wider range of extreme temperatures) and the runners are larger for an L20B.

 

 

 

It's a W58 intake from a '79 truck with the EGR side manifold removed and with some judicious grinding and JB weld smoothed to look like the earlier ones.

 

W58 with EGR manifold...

 

 

EGR manifold removed...

 

 

 

Looks just like the L16 intake...

 

 

A hole and tap gets the PCV valve working and a fitting provides the vacuum for the ATC on the air filter.. All '75-'77 L20Bs had U67 heads and the intake is NOT water cooled/warmed. In fact it is joined and bolted to the exhaust and gets very hot in the summer. L16/18 were also water cooled/warmed. By drilling out the two water holes in the head I converted this one over so I could use the later intake.

 

 

 

Below, installed on a '76 L20B with U67 head and L16 exhaust.

 

[scooter]

I ran my car stock to Alberta many times and it was a u67 l20b and it was fine. Give'r hell