New question; L22s block and a87 peanut head?

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gumby510
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New question; L22s block and a87 peanut head?

Post by gumby510 »

Hello, I was looking at buying a 81 720 z22s engine and rebuild the the bottom end and swapping my a87 peanut head and l20b timing cover.

I didnt see this particular setup in the jason gray lists. Is this going to work or am I going to have to have custom pistons made? Just looking to keep it NA but on the upper end of street compression on midwest 91-93oct.

Thanks
Last edited by gumby510 on 19 Feb 2021 09:54, edited 1 time in total.
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Re: L22s block and a87 peanut head?

Post by Byron510 »

Wow, I didn't think I would forget these numbers, but they are slipping!

I do know from personal experience and measuring that the U67 head, with the 47cc chambers (not machined) on the Z22S block nets just under 10:1 C/R. My current Z22S with a shaved U67 head nets 10.5:1.

I believe that the closed chamber A87 (and closed chamber 210) heads were around 32CC volume - plus or minus, depending on how big the valves are and who did the machine work.
Given the 9cc dish in the stock S pistons at stock bore - now I assume you'll be over-boring - so this has to be taken into account, and the 92mm stroke, and accounting for the crushed head gasket thickness (volume) you use... you'll have to do some math, but I think your C/R will be too high for 92 octane.

Those are my thoughts and experiences. I've built a number of 2.2's with both E and S blocks and always used U67 heads to keep the C/R down.

Hopefully, that helps.

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Re: L22s block and a87 peanut head?

Post by gumby510 »

44mm exhaust
38mm intake

I didnt do the work. Came on the car when I bought it 8 or so years ago. He stated that it was not shaved.

So with that I may have to go the route of custom pistons.
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Re: L22s block and a87 peanut head?

Post by gumby510 »

Byron510 wrote: 27 Jan 2021 07:12 Wow, I didn't think I would forget these numbers, but they are slipping!

I do know from personal experience and measuring that the U67 head, with the 47cc chambers (not machined) on the Z22S block nets just under 10:1 C/R. My current Z22S with a shaved U67 head nets 10.5:1.

I believe that the closed chamber A87 (and closed chamber 210) heads were around 32CC volume - plus or minus, depending on how big the valves are and who did the machine work.
Given the 9cc dish in the stock S pistons at stock bore - now I assume you'll be over-boring - so this has to be taken into account, and the 92mm stroke, and accounting for the crushed head gasket thickness (volume) you use... you'll have to do some math, but I think your C/R will be too high for 92 octane.

Those are my thoughts and experiences. I've built a number of 2.2's with both E and S blocks and always used U67 heads to keep the C/R down.

Hopefully, that helps.

Byron
Alright Byron here is one for you and your wisdom.

Because of where I live (wisconsin) datsuns are few and far between, shipping an engine is expensive let alone finding datsun engine in a junk yard. The ones I do find are minimum 6-8 hours away (boo hoo woe is me, I know). The z20 I had a little over 2 years ago I ended up selling right after I got to a local that was in need. The z22s I was looking at was 6.5hr away and the crushed the car and didnt update there inventory. So now im back to my l18.

Would it be worth my time to build the l18 I have? The head is already built. Perhaps doing a bored long rod 18? Kameari has a l18 pistons that are 89mm (prob would do 88.5mm just to be safer) that I could use with l16 rods making it a 1941cc motor. My reason for thinking this is that I have the engine and can easily get the other parts. I just installed a 4.44 subaru lsd so having a little more reving engine isnt a bad thing. It also seem that going over 87mm on a l18 may not the best idea?

I know saying is it worth my time is subjective. I know it all depends on what im looking to do. For mostly street driving I think either engine would be fun but for the amount of interstate driving a higher reving motor makes a little more sense being paired with the 4.44 and my 280z trans.
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Re: L22s block and a87 peanut head?

Post by Three B's Racing »

gumby510 wrote: 30 Jan 2021 10:14
Byron510 wrote: 27 Jan 2021 07:12 Wow, I didn't think I would forget these numbers, but they are slipping!

I do know from personal experience and measuring that the U67 head, with the 47cc chambers (not machined) on the Z22S block nets just under 10:1 C/R. My current Z22S with a shaved U67 head nets 10.5:1.

I believe that the closed chamber A87 (and closed chamber 210) heads were around 32CC volume - plus or minus, depending on how big the valves are and who did the machine work.
Given the 9cc dish in the stock S pistons at stock bore - now I assume you'll be over-boring - so this has to be taken into account, and the 92mm stroke, and accounting for the crushed head gasket thickness (volume) you use... you'll have to do some math, but I think your C/R will be too high for 92 octane.

Those are my thoughts and experiences. I've built a number of 2.2's with both E and S blocks and always used U67 heads to keep the C/R down.

Hopefully, that helps.

Byron
Alright Byron here is one for you and your wisdom.

Because of where I live (wisconsin) datsuns are few and far between, shipping an engine is expensive let alone finding datsun engine in a junk yard. The ones I do find are minimum 6-8 hours away (boo hoo woe is me, I know). The z20 I had a little over 2 years ago I ended up selling right after I got to a local that was in need. The z22s I was looking at was 6.5hr away and the crushed the car and didnt update there inventory. So now im back to my l18.

Would it be worth my time to build the l18 I have? The head is already built. Perhaps doing a bored long rod 18? Kameari has a l18 pistons that are 89mm (prob would do 88.5mm just to be safer) that I could use with l16 rods making it a 1941cc motor. My reason for thinking this is that I have the engine and can easily get the other parts. I just installed a 4.44 subaru lsd so having a little more reving engine isnt a bad thing. It also seem that going over 87mm on a l18 may not the best idea?

I know saying is it worth my time is subjective. I know it all depends on what im looking to do. For mostly street driving I think either engine would be fun but for the amount of interstate driving a higher reving motor makes a little more sense being paired with the 4.44 and my 280z trans.
The L18 rods are I believe 0.100" shorter than L16 rods so wouldn't using L16 rods with L18 pistons put the pistons .100" above the blocks deck? We used L18 rods in a L16 with stock L16 pistons for a Turbo build back in the late 70's and it dropped the pistons down in the bores considerably really dropping compression which was great for boost, bad for fuel mileage but great for nut cracking acceleration.
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Re: L22s block and a87 peanut head?

Post by gumby510 »

The L18 rods are I believe 0.100" shorter than L16 rods so wouldn't using L16 rods with L18 pistons put the pistons .100" above the blocks deck? We used L18 rods in a L16 with stock L16 pistons for a Turbo build back in the late 70's and it dropped the pistons down in the bores considerably really dropping compression which was great for boost, bad for fuel mileage but great for nut cracking acceleration.
I was going off of the jason gray build sheet
Long rod L18

flattop Z20S pistons and peanut chamber head for 9.7:1 CR, better rod/stroke ratio for higher RPM.

Parts: L18 crank, L18 block, L16 rods, Z20S pistons

s/2+r+p: 207.66mm

piston deck height: -0.29 (below deck)
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Re: L22s block and a87 peanut head?

Post by datzenmike »

Would it be worth my time to build the l18 I have? The head is already built. Perhaps doing a bored long rod 18? Kameari has a l18 pistons that are 89mm (prob would do 88.5mm just to be safer) that I could use with l16 rods making it a 1941cc motor. My reason for thinking this is that I have the engine and can easily get the other parts. I just installed a 4.44 subaru lsd so having a little more reving engine isnt a bad thing. It also seem that going over 87mm on a l18 may not the best idea?

I know saying is it worth my time is subjective. I know it all depends on what im looking to do. For mostly street driving I think either engine would be fun but for the amount of interstate driving a higher reving motor makes a little more sense being paired with the 4.44 and my 280z trans.
L16 rods are 2.8mm longer than L18 rods but you can't use stock L18 pistons with this or they would pop up above the deck by this amount. A custom piston with a 2.8 shorter pin height will work but the stroke remains unaffected and the cylinder volume is the same. IF... the piston was 88.5mm it would increase the L18 to 1,918cc displacement. It would all hang on this mythical Kameari L18 piston's pin height. It would have to be 35.3mm or less. Why not get 1mm oversize Truck Z22 pistons??? They would be 88mm and 35.5mm pin height and produce 1896cc engine.... got to be cheaper and certainly more available!!!!

With a 9cc piston dish....
The above with a 41cc closed chamber head it would have a 10.18 compression or 9.4 with a 45.2cc open chamber. I would go with the U-67 open chamber as they have larger ports than an A87 head.

All L 4 cylinder engines can rev but seldom need to. Here is the 'red line' which is a theoretical limit imposed by the specs of the forged steel rods and fasteners. Beyond this the metal stretches and will eventually fatigue and fail. Below this it can run indefinitely under ideal conditions.

L16.............. 8,250
L18.............. 7,800
L20B............ 7,000

None of these engines in stock trim makes revving over 5K-6K worth the bother. There is just no power there. Modified with a large cam and more carb then yes. If going above 6K definitely better rod bolts for peace of mind, then custom rods, then....
"Nissan 'shit the bed' when they made these, plain and simple." McShagger510 on flattop SUs
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Re: L22s block and a87 peanut head?

Post by gumby510 »

datzenmike wrote: 30 Jan 2021 14:09 {quote]
Would it be worth my time to build the l18 I have? The head is already built. Perhaps doing a bored long rod 18? Kameari has a l18 pistons that are 89mm (prob would do 88.5mm just to be safer) that I could use with l16 rods making it a 1941cc motor. My reason for thinking this is that I have the engine and can easily get the other parts. I just installed a 4.44 subaru lsd so having a little more reving engine isnt a bad thing. It also seem that going over 87mm on a l18 may not the best idea?

I know saying is it worth my time is subjective. I know it all depends on what im looking to do. For mostly street driving I think either engine would be fun but for the amount of interstate driving a higher reving motor makes a little more sense being paired with the 4.44 and my 280z trans.
L16 rods are 2.8mm longer than L18 rods but you can't use stock L18 pistons with this or they would pop up above the deck by this amount. A custom piston with a 2.8 shorter pin height will work but the stroke remains unaffected and the cylinder volume is the same. IF... the piston was 88.5mm it would increase the L18 to 1,918cc displacement. It would all hang on this mythical Kameari L18 piston's pin height. It would have to be 35.3mm or less. Why not get 1mm oversize Truck Z22 pistons??? They would be 88mm and 35.5mm pin height and produce 1896cc engine.... got to be cheaper and certainly more available!!!!

With a 9cc piston dish....
The above with a 41cc closed chamber head it would have a 10.18 compression or 9.4 with a 45.2cc open chamber. I would go with the U-67 open chamber as they have larger ports than an A87 head.

All L 4 cylinder engines can rev but seldom need to. Here is the 'red line' which is a theoretical limit imposed by the specs of the forged steel rods and fasteners. Beyond this the metal stretches and will eventually fatigue and fail. Below this it can run indefinitely under ideal conditions.

L16.............. 8,250
L18.............. 7,800
L20B............ 7,000

None of these engines in stock trim makes revving over 5K-6K worth the bother. There is just no power there. Modified with a large cam and more carb then yes. If going above 6K definitely better rod bolts for peace of mind, then custom rods, then....
[/quote]

I wasnt intending on using the l18 pistons.
Kameari has a 88.5mm piston with a 35.5mm pin height. My only concern with them is there flat with valve relief cuts. Which if everything translated correctly the relief cuts only equal 2.7cc
Nismo headgasket that has a 1.5mm compressed height (allegedly)
Id give these rods a shot. https://www.ebay.com/itm/Connecting-Rod ... 890.l49292

Fuel wise I was going to itb and efi but i have twin solex 40's im going to run instead.
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Re: L22s block and a87 peanut head?

Post by 510rob »

datzenmike wrote: 30 Jan 2021 14:09 All L 4 cylinder engines can rev but seldom need to. Here is the 'red line' which is a theoretical limit imposed by the specs of the forged steel rods and fasteners. Beyond this the metal stretches and will eventually fatigue and fail. Below this it can run indefinitely under ideal conditions.

L16.............. 8,250
L18.............. 7,800
L20B............ 7,000

None of these engines in stock trim makes revving over 5K-6K worth the bother. There is just no power there. Modified with a large cam and more carb then yes. If going above 6K definitely better rod bolts for peace of mind, then custom rods, then....
What is the source of this data or the calculus used to derive these numbers?
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Re: L22s block and a87 peanut head?

Post by datzenmike »

Stroke in inches X RPM must be less than 4000 feet per minute.
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Re: L22s block and a87 peanut head?

Post by datzenmike »

gumby510 wrote: 30 Jan 2021 14:55 I wasnt intending on using the l18 pistons.
Kameari has a 88.5mm piston with a 35.5mm pin height. My only concern with them is there flat with valve relief cuts. Which if everything translated correctly the relief cuts only equal 2.7cc
Nismo headgasket that has a 1.5mm compressed height (allegedly)
Id give these rods a shot. https://www.ebay.com/itm/Connecting-Rod ... 890.l49292

Fuel wise I was going to itb and efi but i have twin solex 40's im going to run instead.
The info above 88.8mm and 1.5mm gasket gives a 9.51 but the 88mm Z22 pistons have got to be easier to source and cheaper. I think almost $60 Canadian each from the dealer. US probably $40??

Pistons and rings for $53...
https://www.ebay.ca/itm/Pistons-and-Rin ... Sw7JtffexI
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Re: L22s block and a87 peanut head?

Post by gumby510 »

datzenmike wrote: 30 Jan 2021 20:46
gumby510 wrote: 30 Jan 2021 14:55 I wasnt intending on using the l18 pistons.
Kameari has a 88.5mm piston with a 35.5mm pin height. My only concern with them is there flat with valve relief cuts. Which if everything translated correctly the relief cuts only equal 2.7cc
Nismo headgasket that has a 1.5mm compressed height (allegedly)
Id give these rods a shot. https://www.ebay.com/itm/Connecting-Rod ... 890.l49292

Fuel wise I was going to itb and efi but i have twin solex 40's im going to run instead.
The info above 88.8mm and 1.5mm gasket gives a 9.51 but the 88mm Z22 pistons have got to be easier to source and cheaper. I think almost $60 Canadian each from the dealer. US probably $40??

Pistons and rings for $53...
https://www.ebay.ca/itm/Pistons-and-Rin ... Sw7JtffexI
Much cheaper and easier to go that route but I worry about the quality and materials used. $53 vs $650 is the quality difference $600? Probably not but id have more confidence in the kameari over the china bay pistons.
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Re: L22s block and a87 peanut head?

Post by 510rob »

datzenmike wrote: 30 Jan 2021 20:22Stroke in inches X RPM must be less than 4000 feet per minute.
Always useful to have a few heuristics, with the theory behind them. Thanks.
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Re: L22s block and a87 peanut head?

Post by gumby510 »

So with a l18 is the long rod ratio of 1.71 vs 1.67 does that really make that much of a difference? Is a long rod worth it over the factory if bore is the same.

I can get the 88.5mm piston in either the l16 rods length pin height of 35.5mm or in the factory l18 rod length of 38mm.
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Re: L22s block and a87 peanut head?

Post by datzenmike »

Generally a long rod allows the piston to remain near TDC slightly longer than a shorter rod. The longer time it is there, the more time the expanding gasses have to push and impart motion to it. Important at high RPMs. All other things equal a longer rod has less side loading on the piston as it approaches and leaves BDC so less vibration and friction. No, it makes very little difference, it's splitting hairs. Any rod stroke ratio over 1.5 is fine.
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