cylinder head exchange or rebuild

[maredlin1@hotmail.com]

Have a 1978 l20b 620 with closed chamber (peanut head) that has round ports. Does any one know where I can get a cylinder head exchange or rebuild for this head ? Also what type of 86 mm pistons would I use for a daily driver?

[john510]

Dont exchange that head have it rebuilt if possible.

[maredlin1@hotmail.com]

It is w58 closed chamber that I would like rebuilt, but don' know where to send it. Also will run a 32/36 weber and need to know what 86 mm pistons to use.

[DanielC]

It is a desirable head to have.  You want to rebuild this head, if possible.

 

Rebuilding a Datsun OHC cylinder head is more complicated than rebuilding a cylinder head off some American V-8.  The valve stem heights are critical, for the rocker arm geometry to be correct, and it cannot be adjusted with a different pushrod, or adjustable rocker arm.   

 

You might try asking at your local Nissan dealer who does their cylinder head work.  

[620Turbo4X4]

I would look for a machine shop that specializes in performance builds. Have no idea what you have in your area. Get out the yellow pages and let your fingers do the walking...

 

You'll want to find a FSM and print out the pages the deal with valve train specification and bring that too. As mentioned above there is more involved than the typical sbc. If head is warped have both bottom and top machined flat so cam dosen't bind and chew up bearings. Makes for noisy valve train too...

 

Why 86mm pistons? Stock head gaskets begin to protrude into the cylinder when you get above 85.5. Nismo head gaskets have a larger fire ring, but are 4 times the cost. Ideally you would want flat tops to get good turbulence with closed heads, but compression #'s will be up there pretty high for pump gas unless some massaging and un-shrouding is done to combustion chamber

 

I'm running l18 Pistons in my l20 w closed head

[Stoffregen Motorsports]

There's a shop in Westminster, quite a ways north of you, that does Nissan/Datsun. http://rallye-sport.com/

[banzai510(hainz)]

Why 86mm pistons?

 

same question

all L20s are 85mm unless you want this bored out then youll need to get a better gasket that is wider. What I have seen.

 

most start out 20thou over then work your way up unless ypou want flattop piston then its the non turbo 280zx flattop that is most likely sold for this.

But flattops on a dlaily driver closed chamber head to too much comp for the gas sold

[maredlin1@hotmail.com]

I was going to go with 86mm, because I read a reply to someone by Datsun Mike, and I believe he stated he would go with a 86mm because stock pistons are available for z cars. I really don't care what I should use for pistons, just want the best performance with pump gas. I realize that is a hard combination to achieve. I do appreciate any and all suggestions.

[docbainey]

Have a 1978 l20b 620 with closed chamber (peanut head) that has round ports. Does any one know where I can get a cylinder head exchange or rebuild for this head ? Also what type of 86 mm pistons would I use for a daily driver?

 

Just Google, There is at least 4 or 5 automotive machine shops in the Silver Springs area, just up the road from Fountain. Call or go see them.

 

https://www.google.com/?gws_rd=ssl#q=fountain+colorado+automotive+machine+shop