A87 VS W58

[rojadoja]

I have a 79 620 with a W58 head and I picked up an A87-Open chamber in really nice shape. Any input on weather or not it would be a beneficial swap? As far as I have read it sounds like the W58 sucks ass, but since my A87 is not a closed chamber peanut head, will there be any gains?

[izzo]

check olddatsuns.com for some specs on differences between the heads. think the w58 has the intake liners which are kinda lame. W58 is an emissions head really, pretty sure the A87 even open chamber will be better

[izzo]

The W58

Open(with rare exceptions) This is the L-20B smog head usually found on '77 and later engines. 1.375" intake ports with ROUND exhaust ports. These exhaust ports have steel liners that help burn off emissions. I know of one of these castings that has closed chambers. These heads don't flow well and are avoided for high-performance applications.

 

 

A87

found on many L-18 and L-20B's. The "domestic" version usually came with open chambers. Many of the "used Japanese import" engines came with the peanut version of this head. Large quantities of these used engines were imported in the 80's, so the peanut version is fairly common. These heads usually have 1.25" intake ports and square exhaust ports. 1.65" intake valves. Exhaust valves can be 1.38" or 1.30"

[Skib]

depends on what kinda shape there in.

 

 

your not going to notice any performance gains driving around.

 

 

 

if you swap the heads do you know the condition of the valves, valve seats and valve stem seals?

[rojadoja]

yeah thats all of the info I could drag out of olddatsuns too. Thanks for the info. I know there has got to be someone that has done this swap. I'll just let this post stew for the night.

[rojadoja]

depends on what kinda shape there in.

 

 

your not going to notice any performance gains driving around.

 

 

 

if you swap the heads do you know the condition of the valves, valve seats and valve stem seals?

 

Valves/stems/valvetrain in killer shape, I was really surprised when I pulled the head.

[Skib]

its really up to you.

 

 

do you feel like pulling a head? lol

 

 

I like my W58, but then again its a closed chamber head :lol:

 

 

 

I personally wouldnt bother changing it out unless you had a closed chamber to put on it.

I wouldnt want to do the work just to be changing to another open chamber.

[rojadoja]

its really up to you.

 

 

do you feel like pulling a head? lol

 

 

I like my W58, but then again its a closed chamber head :lol:

 

 

 

I personally wouldnt bother changing it out unless you had a closed chamber to put on it.

I wouldnt want to do the work just to be changing to another open chamber.

 

Gotcha. By the way thanks for rubbing it in that you have a w58 closed chamber Thanks for the knowledge! I will try and pawn this thing off and nurture my w58.

 

[datsunaholic]

Big issue is you'd also have to change your exhaust manifold. You do NOT want to use a round-port exhaust manifold with a square-port head. The other way "works" but it's not optimal.

 

The A87 will have smaller intake ports too.

[banzai510(hainz)]

Waist of time brother!!!!!!!!!!!

 

Put a 38/38 DGES weber on there if anything