L-20b rebuild

[john510]

My rebuild continues on,got the block done.L-18 pistons .040 over,reground crank all new bearings.Just put the head on the other night.A87 peanut head that is ported.I chose the Web cam .488 lift 252 duration cam, resurfaced rockers and schneider valve springs.All this stuff is getting expensive it better run good.

 

 

 

 

 

 

 

The last picture is the motor before i tore it apart

[Zeusimo]

:w00t:

[datzenmike]

Wow that's 9.85 compression. I applaud the sensible daily driver 252 duration, an extremely modest increase over stock. Love the lift. That should add across the board without making it 'peaky'.

 

Sorry assumed flattops. Dished pistons would be 9.158

[john510]

I chose that cam because they say it has a strong broad powerband.A lot of the cams i checked into the power is good from about 3250-7250 rpms and i really dont want to rev the shit out this engine.

[Wide14u]

i would be happy with that :D

[Sealik]

Be interesting to see how that cam works out for ya....will have one with similar specs..256/491

Less compression though.

[banzai510(hainz)]

john

I have 2 of these cams also but never installed them.

I think its a perfect grind but youll be the first to let us know about it.

 

I hope your going to run sidedrafts on this. well maybe run a drowndraft to break it in. bUT MOST POWER GAINS WILL BE THE FROM THE SIDEDRAFTS,port matching and the cam.

 

another thing do you want those water ports open. you can get a 1/4 pipe plug. 1/4 in meaning the allen wrench size but the threading size is different. I did mine this way and installed the pipe plugs as once you put sidedrafts its just alot less hassle to deal with the water leaks and sidedrafts dont need water passages anyways. So best time to do that is NOW.

 

remember to prime the oil pump.

 

whats the setting on the cam sprocket? 1 2 or 3 .??????

[john510]

Hainz,im running SU's the manifold is port matched to the head.Im going to use the water ports ive never had a problem with leaks,i always use the nissan manifold gasket.I have a distributor- oil pump shaft that i took the gear off of so priming will be a lot easier.I got the cam gear set on number 1 because i put in a new chain and sprockets also new tensioner and guides.I know the L20 comes factory set on number 2 so i was not sure where to start with a different cam.Any suggestions ?

[banzai510(hainz)]

if your running SUs then yes dont worry about the water passages. I was think more like webers or Mikunis when you use those manifolds.

 

as for the cam setting? I myself am not a expert on this. But they say power comes on sooner when cam is more adv.

This being a daily driver you think one would want power sooner unless your a all out road racer where your in the high rmps all the time.

I myself your try #2 or maybe #3

[datzenmike]

The number is just a starting point. Factory L20B cam sprockets and chain are set on the #2 at TDC. But the deciding factor is the relationship of the horizontal etch mark on the cam thrust plate, to the notch in the cam sprocket. The etch mark should be above or slightly to the left of the notch. To the right is no good and the sprocket should be moved to the next number up.

 

Correct relationship below:

 

.

[john510]

Datzenmike,its right on just like your picture,thanks.Hainz ive watched your video probably 10 times just so i get this done right.I did the head gasket and put an L20b cam in the L18 thats is in the car now,so far no problems.Thanks guys.

[banzai510(hainz)]

i always use the nissan manifold gasket.

 

In a pinch you can use a Felpro gasket as its the same SSS spec size on the intakes. 1.5 inch. Incase the SSS intake/exhaust gaskets are harder to get.

 

I did the head gasket and put an L20b cam in the L18 thats is in the car now,so far no problems.

If you can do a head gasket then you can do a L motor!!!!!!!!!!!!!!!