L20B A87 combo

[JumboFett]

Hey y’all,

If using a stock L20B bottom end, is the A87 head plus L20B cam combo the best setup for the street?

Thank you 

[banzai510(hainz)]

L20 bottom with a closed chamber A87 is VERY GOOD. L20Cam is nothing spec. same as a SSS I believe back in the day

matchport the intake to a 1.5 intake manifold if its a 1.5 size. alot of intakes are not 1.5in

 

Most A87s is just a L18 head. Some are closed and most are open I believe.

The W53 was a closed chamber but 1.25in intake ports

Edited October 10, 2022 by banzai510(hainz)

[datzenmike]

It's ok but you'll have to look at the combustion chambers to know if closed or open. If head is on the engine no easy way to tell.

 

A87 heads had small 32mm (1.25”) intake ports and intake valves are 42mm (1.65”) while exhaust valves can be either 33mm (1.30") or 35mm (1.38”). All A87 heads in N America were on one year only ('74) L18 engines and only the first year L20B in the '74 610 had them. With the small intake port it will give good air speed at mid RPMs good torque and mileage.

 

U67 head is better with larger 35mm (1.375”) intake ports and also square exhaust ports.  Intake valves are 42mm (1.65”) while exhaust valves are the familiar 35mm (1.38”). 

 

Both use the same cam. The A87 heads allow coolant to pass into runners in the intake to warm them in cold weather and cool them in hot. The U67 does not, but you can drill two 3/8" holes easily enough for use on engines that did have this feature. Nothing wrong with the A87 head but you asked about head and cam best setup for the street.

[JumboFett]

2 minutes ago, datzenmike said:

It's ok but you'll have to look at the combustion chambers to know if closed or open. If head is on the engine no easy way to tell.

 

A87 heads had small 32mm (1.25”) intake ports and intake valves are 42mm (1.65”) while exhaust valves can be either 33mm (1.30") or 35mm (1.38”). All A87 heads in N America were on one year only ('74) L18 engines and only the first year L20B in the '74 610 had them. With the small intake port it will give good air speed at mid RPMs good torque and mileage.

 

U67 head is better with larger 35mm (1.375”) intake ports and also square exhaust ports.  Intake valves are 42mm (1.65”) while exhaust valves are the familiar 35mm (1.38”). 

 

Both use the same cam. The A87 heads allow coolant to pass into runners in the intake to warm them in cold weather and cool them in hot. The U67 does not, but you can drill two 3/8" holes easily enough for use on engines that did have this feature. Nothing wrong with the A87 head but you asked about head and cam best setup for the street.

It’s a closed chamber peanut head. What I’m really hoping for is a slight increase in compression. 

[banzai510(hainz)]

4 minutes ago, JumboFett said:

closed chamber peanut head. What I’m really hoping for is a slight increase in compression. 

Perect. you cam match port to your intake if you have a larger than 1.25

[datzenmike]

Look along the front edge maybe on the distributor side for 219 cast into it. Some 219 castings were cast with A87 on the plug side. Now you really have a winner. The 219 was an SSS head with both large valves and ports and small combustion chamber. None of the heads on cars coming to N America had closed chamber heads. Many barge loads of heads came from Japan because it was cheaper to just swap them than do a valve job on them and some were closed chamber. A 219 head is highly sought after. All Nismo 219 heads were used up for high performance applications and the demand prompted Nissan to re-cast new ones called the 912 so a few of them will be 'out there' also.

 

An un-shaved closed chamber head will raise the stock L20B compression from 8.4 to 8.9.

[JumboFett]

3 minutes ago, banzai510(hainz) said:

Perect. you cam match port to your intake if you have a larger than 1.25

I have a cannon manifold with a 32/36, so I’ll definitely look into that.

[JumboFett]

1 minute ago, datzenmike said:

Look along the front edge maybe on the distributor side for 219 cast into it. Some 219 castings were cast with A87 on the plug side. Now you really have a winner. The 219 was an SSS head with both large valves and ports and small combustion chamber. None of the head on cars coming to N America had closed chamber heads. A 219 head is highly sought after. All Nismo 219 heads were used up for high performance applications and the demand prompted Nissan to re-cast new ones called the 912 so a few of them will be 'out there' also.

 

An un-shaved closed chamber head will raise the stock L20B compression from 8.4 to 8.9.

Thanks! I’ll definitely keep that in mind! Dude also said he had a Nissan “C” cam with the head; he says it was a competition option cam. I tried to look it up but couldn’t find any info. Y’all know what that is, or what the specs might be?

[banzai510(hainz)]

take a photo of the cam lobes. if a regrind then one will notice it right away .

 

 

[datzenmike]

You will not like a competition cam because it for COMPETITION. You want something that idles good with good intake vacuum, starts good in cold weather, docile in stop and go traffic, pulls hard and even from idle to 4 or 5 k, and gets reasonable mileage. A competition cam does not idle well because it almost never idles in a race, only has to start once for a race, never any stop and go in a race, power only comes on above 6,500, who cares about mileage in a race?

[Farmer]

A87 closed chamber, port match, l20b  block, L18 pistons, great combo

[JumboFett]

20 hours ago, datzenmike said:

You will not like a competition cam because it for COMPETITION. You want something that idles good with good intake vacuum, starts good in cold weather, docile in stop and go traffic, pulls hard and even from idle to 4 or 5 k, and gets reasonable mileage. A competition cam does not idle well because it almost never idles in a race, only has to start once for a race, never any stop and go in a race, power only comes on above 6,500, who cares about mileage in a race?

I hear that, but I’m just asking because someone’s definition of competition might differ from another’s. Like, if this “competition” cam moves my powerband up from idle-4000 to 1500-5500 then I’m gonna want that cam. But if it’s a cam that’s only likes to be above 3000 then it’s going up for sale. 

[JumboFett]

21 hours ago, Farmer said:

A87 closed chamber, port match, l20b  block, L18 pistons, great combo

That would be, but I’m not doing the bottom end. 

[datzenmike]

1 hour ago, JumboFett said:

I hear that, but I’m just asking because someone’s definition of competition might differ from another’s. Like, if this “competition” cam moves my powerband up from idle-4000 to 1500-5500 then I’m gonna want that cam. But if it’s a cam that’s only likes to be above 3000 then it’s going up for sale. 

 

You said Nissan Competition C cam. If so it will be for racing requiring header, multi carburetor, high compression, ultra close ratio transmission. It will likely only be happy above 6k. 

[banzai510(hainz)]

photo or the cam up close.

C could just be a casting letter of no importance. Most have a number of soem sort at the back of the cam.

[Stoffregen Motorsports]

A "C" cam is not a competition cam. They were stamped on the back with A, B and C from the factory. I forget which one is the better one, but they are all basically the same.