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what goes on a l20b block? is it just


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L20 came with several different heads. They are known by their casting number. W53 w58 u67 a87 etc. Some have bigger valves than others and some have bigger ports. Some are open chambered and some are closed. Olddatsuns.com has a pretty good breakdown of whats what. Cruise over and read about head id and if you still have questions then ask away!

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Olddatsuns.com has a pretty good breakdown of whats what. Cruise over and read about head id and if you still have questions then ask away!

I don't see that at http://olddatsuns.com/

 

 

L20B came with U67/N58 or W58 heads. In Australia came with V91 heads.

 

U67 dry manifold, square port exhaust

W58/N58 wet manifold, round port exhaust

 

Valve sizes intake/exhaust (mm)

42/33 L20B

42/35 L20B

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I don't see that at http://olddatsuns.com/

 

 

L20B came with U67/N58 or W58 heads. In Australia came with V91 heads.

 

U67 dry manifold, square port exhaust

W58/N58 wet manifold, round port exhaust

 

Valve sizes intake/exhaust (mm)

42/33 L20B

42/35 L20B

what do you mean by dry/wet manifold. My understanding is that a "dry" manifold is only an air guide with fuel being delivered directly. I know Datun aint doing that on the L20b.

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You should try to stay with the nicest one that matches your exhaust ports,, unless he has a exhaust manifold (and Y pipe) you could buy also.   Bigger valves / larger ports won't really be noticed on normal day to day driving.

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A87 open chamber(round port Square port) $90
W58 open chamber(round port round port) $75
W58 semi peanut chamber(round port round port) $75
210 simi peanut chamber(round port square port) $60

 

 

I assume you want it for the '77 listed in your profile??? If so the L20b from '75 through '77 used a U-67 head on all cars and trucks. After '77 a W58 was used. You want a U-67 head with square exhaust ports to properly match your exhaust manifold. The best match is the A87 head. You do NOT want the 210 head which is for an L16 and has smaller ports and valves. The W58 have round exhaust ports.

 

You'll note that the A87 has coolant ports just below the two pair of round intake runners. Your U67 doesn't have these and has the intake and exhaust manifolds joined together under the carb. This allows hot exhaust to warm the intake air. Don't worry the '77 intake does not have these matching ports and the passages will be sealed off when the manifold is installed.

 

Your L20B cam and rockers can be swapped in... try to keep the rockers in the same position they came out of.

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Can't tell much from this picture. You would have to see the casting numbers to be sure

 

00f0f_kKUjJeTDFAM_600x450.jpg

 

Top two are likely the W58s as they have round exhaust ports. The second one is for sure as it has the exhaust liners. The top one is round and no liners but maybe removed as the second one has two missing and one crumpled up.

 

The bottom two could be anything except a W58 and not likely a U67 as they do have coolant posts for the intake.

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