Head ID

[lil89ram50]

i would like to start this thread to help new guys out, or the ones like me that have not known.

 

what are the differences between the heads? and pics to show the differences. pro's cons, comparisons.

 

reason i start this is becuase i need to know how to tell if i have an open or cosed chambered head. its a w58 peanut head. will post pics later.

[ggzilla]

i need to know how to tell if i have an open or cosed chambered head

 

A, B and D are closed chamber

C is open chamber. It's round all around

Difference is about 2% hp.

[Skib]

its a w58 peanut head.

 

 

closed chamber heads are refereed to as "peanut" heads

[lil89ram50]

ok so closed chambered is just weeather or not its peanut thing, i thought it had to do with the valves.

[Skib]

nope. valve position is the same on L4 heads but the valves sizes are different on some.

 

 

from "how to modify your Nissan/Datsun OHC engine"

 

L16 early:

intake valve diameter: 38mm

exhaust valve diameter: 33mm

 

L16 late:

intake valve diameter: 42mm

exhaust valve diameter: 33mm

 

L18:

intake valve diameter: 42mm

exhaust valve diameter: 33mm

 

L20B:

intake valve diameter: 42mm

exhaust valve diameter: 35mm

[lil89ram50]

so what are the diffences between say a u67, u20, w50, 210, and the ones i didnt list? what makes one more sought after than the other?

[Z chopper]

I am curious as to which head was used on the bluebird sss engine.

What head is best for torque

what head is best for power

[datzenmike]

I am curious as to which head was used on the bluebird sss engine.

 

 

The SSS head was the 219 casting with huge 1.5" intake ports and valves. Very rare to find them today as most were snapped up for racing and that usually destroys them from the hard use. This head ia very desirable for certain classes of racing where it can be considered a 'stock Nissan' head. Nissan, seeing a market for this head, mainly for racing, re-introduced it again years later as the V912 casting. A rebuildable one is worth $350 and a good one 2 to 3 times that.

 

 

What head is best for torque

what head is best for power

 

Using the same cam: a smaller valve and port head is more efficient at mid RPMs where the intake velocity is high but this will choke off top end power. The opposite is true for larger valves and ports with better breathing at higher RPMs and more power. On a stock motor the differences are not much but on a built motor it becomes very apparent. In all cases an after market cam will move all torque and power higher in the RPM range at the expense of good strong idle and low speed driving characteristics.

[Z chopper]

ok which is better open or closed chamber?

 

 

[datzenmike]

Well performance better or economy better? Peanut heads are higher compression so they more efficiently capture the heat energy and use it but you run the risk of pre-ignition or pinging and may have to run premium ga$. They are great for racing where every hp is an advantage but on the street you probably won't notice it.

[lil89ram50]

Ok, so my question still persists, whats the difference between the different series heads?

[datzenmike]

Here you can read for yourself...

 

L head ID

[ggzilla]

So i read that L16 closed-chamber heads have larger chamber (41.5 cc) than L16 open chamber heads (38.5 cc). Is that a typo?

 

original SSS head ...The "peanut" combustion chamber volume was approximately 41cc...Most of the open-chamber heads found on the L-16 had a chamber volume of 38.5cc.

[wayno]

Ok, so my question still persists, whats the difference between the different series heads?

 

There is a lot more to it than just the head, if you have a U67 open chamber head, you can run flat top pistons to bring up your C/R. If you have a W53 closed chamber(peanut) then you would run a dished piston to get the same C/R as what I discribed above. The W58 head is an emmisions head with round exhaust ports, I am not saying there is anything wrong with the head, there just not sought after for performance engines, but for street use there as good as anything else I suppose. Here is a link about the differant heads.

http://www.olddatsuns.com/html/tech/head_ID_2.htm

[datzenmike]

Nope, I think the L16s that had the closed chamber heads also had flattop pistons too. Only the flattop pistons make the closed chamber head work properly. There has to be a pinch or quench area where the piston top and the head surface are separated only by the head gasket thickness. Dished pistons like the L20B only have true quench in a ring around the outer edge.

 

An L16 stock compression is 8.58

Adding a closed chamber head and stock pistons...8.21

L16 with flattops and closed chamber head....9.2

 

 

The exhaust liners can be removed from the W-58 and other than the exhaust port shape it pretty much a U-67.

[wayno]

Hey datzenmike, I was just trying to get an idea across. If you use a Z22e flat top piston block, and put a closed chamber L head on it, generally you would have to high of a C/R for the gas sold at the pump, is this correct?

[Z chopper]

from what I gathered from reading all this is closed chamber head with flat top pistons you need to use high octane fuel to get full effect

[wayno]

from what I gathered from reading all this is closed chamber head with flat top pistons you need to use high octane fuel to get full effect

 

There are so many variables, but in general, i beleave this statement is correct. There are so many differant engines out there made so many differant ways. one of the guys was going to put a peanut head on a Z22e block a while ago, turned out the compression ratio was somewhere around 9.5 to 1 or almost 10 to 1, I can't remember exactly what it was, it was to high for pump gas I beleave, so the guy bailed on that build. I put together a Z22 block with Z24 dished pistons, with a W53 closed chamber head, it supposedly is about 8.9 to 1. I can hear it knock a little when the engine gets really warm(i had to replace the thermostat today).

[lil89ram50]

Casting # Chamber type Description

A87 open or closed 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"

W53 closed (with some exceptions) This head is from the Japanese market. Some of these castings are for factory fuel injected engines and have notches in the intake ports to accommodate injectors. 1.25" intake ports and square exhaust ports. 1.65" intake valves and 1.38" exhaust valves.

 

219

 

11041-V9182

closed The true SSS head from imported used engines or ordered from the Datsun comp. catalog. Later versions could be ordered from the catalog with a V912 casting. 1.50" intake ports, square exhaust ports. 1.65" intake valves and 1.38" exhaust. These are hard to find. Any of the other closed chamber heads can be "converted' to this design by simply opening up the intake port to 1.50" (if that's desired) Some of these heads are marked "A87" on the side, but have "219" cast at the front of the head, just below the timing chain inspection plate.

 

210

(some have no number)

 

11041-N2202 SV

open (with rare exceptions) This is the head that came stock on the 510. Tiny 1.125" intake ports, square exhaust ports. 1.50" intake valves and 1.30" exhaust valves. There have been variations reported on the valve sizes. This head is believed to be originally designed for the L-13, and engine never imported to the U.S. I know of one that has the peanut (closed) chamber with 37cc displacement. The earliest versions had more of a "semi-open" chamber design but later examples were the open chamber design. These heads are usually avoided on performance applications.

U67 open The stock cylinder head for many L-20B's. 1.375" intake ports, square exhaust ports. 1.65" intake and 1.38" exhaust valves.

U60 open Identical to the U67 head, this number has been found on very early L-20B's. It seems to be fairly rare.

 

W58

 

11041-W5880

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.

N56 open(?) This is an emissions head that appears to be identical to the W58 casting.

The combustion chamber design has not been verified yet, but is probably open.

 

 

Ok, so according to this i have a pretty hard to find head? doesnt mean its any good, but hard to find? this guy said he has only seen one? any one else know of one of these?

 

[datzenmike]

Hey datzenmike, I was just trying to get an idea across. If you use a Z22e flat top piston block, and put a closed chamber L head on it, generally you would have to high of a C/R for the gas sold at the pump, is this correct?

 

 

There are so many variables, but in general, i beleave this statement is correct. There are so many differant engines out there made so many differant ways. one of the guys was going to put a peanut head on a Z22e block a while ago, turned out the compression ratio was somewhere around 9.5 to 1 or almost 10 to 1, I can't remember exactly what it was, it was to high for pump gas I beleave, so the guy bailed on that build. I put together a Z22 block with Z24 dished pistons, with a W53 closed chamber head, it supposedly is about 8.9 to 1. I can hear it knock a little when the engine gets really warm(i had to replace the thermostat today).

 

Sorry, missed you posts...

 

The Z20E and L20B are basically the same block so if running flattops on a 2 liter L20B or Z22E with peanut chamber head the compression would be... 10.65 and 9.9 with open chamber head.

[datzenmike]

W58

 

11041-W5880

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.

N56 open(?) This is an emissions head that appears to be identical to the W58 casting.

The combustion chamber design has not been verified yet, but is probably open.

 

 

Ok, so according to this i have a pretty hard to find head? doesnt mean its any good, but hard to find? this guy said he has only seen one? any one else know of one of these?

 

I had one of these. They were not offered on any cars I know of on N Am cars or trucks. The one I had was from a yard and had a '79 200sx tag on it. All I can add is a theory hat I have as to where these come from....

 

In Japan the cars are removed from the road when they exceed a certain mileage. These low mileage engines are cheaper to import than to rebuild the same motor here. In the '80's this was a common practice to drop an import motor in. This is why we have L16/18 SSS intakes with dual SUs, L series EFI intakes and the odd long dogleg trannys around. Possibly these closed chamber heads were imported on Japanese motors.???

[ggzilla]

W58 with closed chamber is an excellent head for low and mid-speed HP. If you don't rev the engine over 5k, that would be the head to use.

[lil89ram50]

thats what im looking for is mid and low, mainly all in town driving. and datzenmike, i read somewhere you said you could remove the intake linings in the w58, would that be something worth doing? and is it hard to do?

[ggzilla]

If you remove the linings, you wont' get the great low-speed power. Removing them is a high-RPM mod.

[datzenmike]

Size for size increasing or decreasing the exhaust ports has less effect than increasing or restricting the intake side. Exhaust is under pressure and it wants OUT! Those liners have minimal effect at low mid speeds and as ggzilla says it's really a mod for higher RPM breathing.

 

I removed a set once. Took 45 min for the first one and about 10 min for the last after I figured out the best way. Basically remove the valve and use a 6" chizzel to slice down the length of the liner in 2 or 3 places and split it open and colapse it into the middle of the port. You will need a small pry bar to crumple the 'soft' steel liner and some vice grips. There are several bumps cast into the port wall to support the liner and keep it from conducting heat to the head surface. This allows the liner to get glowing hot and burn off unburnt hydrocarbons. Just leave them or grind them off.