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L20 swap for 510


JDH6

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Hi all,

I currently have a l16, A87 head, with a 200sx 5 speed dogleg tranny in my 69 510. I am wanting to gain some more power, thinking about an L20. How hard would it be to do? Or what would the experienced people recommend I do for power ? Or mods to a L20 ? Any advice would be greatly appreciated! 

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I'm not positive about the 510 but I did it in a 521 (truck) it's a direct swap. Depending on what head and carburetor(s) you have you might not notice much of a power gain.

Edited by bastardo
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At least 20 more hp and way more torque. Use the L16 intake and exhaust and the oil pan and engine brackets on the L20B. You can't use the L16 flywheel so you'll need one from an L20B or larger engine. The flywheel you pick will also determine the pressure plate size. Car flywheels were 200mm and truck 225mm. Either will work just fine. Make sure the release bearing collar matches the PP you decide to go with.

 

Depends on the L20B but definitely run the L 16 exhaust but if you can find a '78-'80 intake and carb that would be better. The later L20B also came with an electronic ignition which also would be nice and get rid of the points. It would need some wiring but not that hard to do. This is as close to a drop in swap as there is. The L20B block is 3/4" taller but visually they both look very much the same.

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5 minutes ago, datzenmike said:

At least 20 more hp and way more torque. Use the L16 intake and exhaust and the oil pan and engine brackets on the L20B. You can't use the L16 flywheel so you'll need one from an L20B or larger engine. The flywheel you pick will also determine the pressure plate size. Car flywheels were 200mm and truck 225mm. Either will work just fine. Make sure the release bearing collar matches the PP you decide to go with.

 

Depends on the L20B but definitely run the L 16 exhaust but if you can find a '78-'80 intake and carb that would be better. The later L20B also came with an electronic ignition which also would be nice and get rid of the points. It would need some wiring but not that hard to do. This is as close to a drop in swap as there is. The L20B block is 3/4" taller but visually they both look very much the same.

Would you recommend an aftermarket header for it? And say dual Weber’s ? What would be the best engine mods. ? Thanks for the advice 

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22 minutes ago, bastardo said:

I'm not positive about the 510 but I did it in a 521 (truck) it's a direct swap. Depending on what head and carburetor(s) you have you might not notice much of a power gain.

Thanks for the reply! 

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19 minutes ago, JDH6 said:

 

Would you recommend an aftermarket header for it? And say dual Weber’s ? What would be the best engine mods. ? Thanks for the advice 


I did a LZ22 (plenty of information on here) with dual Mikuni carbs. It sounded sick but I had really heavy wheels and was never able to tune the carbs properly. Then I sold it.

Best mod is a matchbox distributor, then a Weber downdraft or dual sidedrafts, then bore it and find a peanut head.

The matchbox won't really add power but it gives you a hotter(?) spark and eliminates maintenance of the points.

Edited by bastardo
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37 minutes ago, JDH6 said:

 

Would you recommend an aftermarket header for it? And say dual Weber’s ? What would be the best engine mods. ? Thanks for the advice 

 

Collective groan for all Ratsun members.

 

NO to the header. The L16 cast iron header is at least as good as a boughten after market header. You would have to heavily modify your engine to get it to the point where the L16 exhaust is more restrictive. You already have one, there's nothing to buy with your L16 manifold. It will NEVER wear out, or leak, it won't rust out, it already fits perfectly, it's quiet and the under hood temperatures are less. The only advantage with a boughten header is it's lighter.

 

RFFQD1p.jpg

 

To get the most out of multiple carbs you really need a bit more cam. This is a lot of money. Myself I would first get a 4.11 ratio differential. This revs the engine faster and increases acceleration with no engine mods at all. Fairly cheap and easy to do. Then maybe a Weber... depend how much you want to spend and how you plan to drive the car. If a daily driver I would keep it simple. Modified cars are hard to live with, fun, but not really as drive able.

 

 

I put an L20B into my 521 back in the day. Didn't notice much difference but it pulled hard in lower gears than the L16. Revving it out was unimpressive but up shifting at low speeds felt nice. This is a truck a 2,300 pound 510 will be even better.

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55 minutes ago, datzenmike said:

 

Collective groan for all Ratsun members.

 

NO to the header. The L16 cast iron header is at least as good as a boughten after market header. You would have to heavily modify your engine to get it to the point where the L16 exhaust is more restrictive. You already have one, there's nothing to buy with your L16 manifold. It will NEVER wear out, or leak, it won't rust out, it already fits perfectly, it's quiet and the under hood temperatures are less. The only advantage with a boughten header is it's lighter.

 

RFFQD1p.jpg

 

To get the most out of multiple carbs you really need a bit more cam. This is a lot of money. Myself I would first get a 4.11 ratio differential. This revs the engine faster and increases acceleration with no engine mods at all. Fairly cheap and easy to do. Then maybe a Weber... depend how much you want to spend and how you plan to drive the car. If a daily driver I would keep it simple. Modified cars are hard to live with, fun, but not really as drive able.

 

 

I put an L20B into my 521 back in the day. Didn't notice much difference but it pulled hard in lower gears than the L16. Revving it out was unimpressive but up shifting at low speeds felt nice. This is a truck a 2,300 pound 510 will be even better.

Great, would you recommend a LZ22 build over the L20? I was reading up on the forums about people building them. I have a 4.11 now. 

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1 hour ago, bastardo said:


I did a LZ22 (plenty of information on here) with dual Mikuni carbs. It sounded sick but I had really heavy wheels and was never able to tune the carbs properly. Then I sold it.

Best mod is a matchbox distributor, then a Weber downdraft or dual sidedrafts, then bore it and find a peanut head.

The matchbox won't really add power but it gives you a hotter(?) spark and eliminates maintenance of the points.

Makes sense! Thanks for the info, I’ll do some research on the 22

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Definitely go for more displacement if you can swing it. Basically it's a Z22 block and internals but everything else... will be from an L20B... head, timing chain and cover and the oil pan and pick up will be from the L16.  

 

If you bore the Z22 block from 87mm to 89mm you can fit stock KA24E pistons and this will bump it to 2,300cc

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19 minutes ago, datzenmike said:

Definitely go for more displacement if you can swing it. Basically it's a Z22 block and internals but everything else... will be from an L20B... head, timing chain and cover and the oil pan and pick up will be from the L16.  

 

If you bore the Z22 block from 87mm to 89mm you can fit stock KA24E pistons and this will bump it to 2,300cc

Is that a fairly simple block to install? Would it work with my 200sx 5 speed, and would a A87 Head work on that, from my L16?

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The Z22 block is exactly the same as the L20B but with a larger bore.

 

You have an A87 on an L16???? that gives you a 7.72 compression. You need the stock 210 head for 8.5

 

Myself I would rather have a stouter 5 speed like a 71B. The S10 dogleg is light even for an L20B.

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2 minutes ago, datzenmike said:

The Z22 block is exactly the same as the L20B but with a larger bore.

 

You have an A87 on an L16???? that gives you a 7.72 compression. You need the stock 210 head for 8.5

 

Myself I would rather have a stouter 5 speed like a 71B. The S10 dogleg is light even for an L20B.

Yep A87 I purchased the car a few months ago and that was what was on it, what would the ideal head be for a Z22 block with KA pistons? Thanks again for all of the advice!

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Any open chamber L head. I would prefer the U67 but your A87 will do. I assume it's an open chamber design. If closed your L16 would be 8.2 and with 2,300cc the compression would be too high. Keep in mind that with a 2,300cc engine you are trying to flow 15% more air through it than an L20B. You want the largest ports and valves  .

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9 minutes ago, datzenmike said:

Any open chamber L head. I would prefer the U67 but your A87 will do. I assume it's an open chamber design. If closed your L16 would be 8.2 and with 2,300cc the compression would be too high. Keep in mind that with a 2,300cc engine you are trying to flow 15% more air through it than an L20B. You want the largest ports and valves  .

Ok, makes sense. Thanks for all of the help!

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The SD diesels, KA24DE, RB and others do have them to reduce piston temperatures and detonation. Maybe Troy is misdirecting the competition.

 

 

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key is clutch set up. what size flywheel you have!!!!!!!!!200 or 225mm this tetermines the T?O bearing set up.

simple is get a 200mm flywheel for a L20 seden as they had the 200mm and you can use your 510 T/O bearing demensions(just get new and get a roadsterclutch.

 

use the 510 oil pan and oil pick up.

keep the 510 exhaust.

 

that's about it

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What head is on the L20B? Square port heads are better than round port heads.

 

I would keep the L16 exhaust and intake manifolds, get a Weber 32/36 DGV, have the original L16 distributor re-curved and install a Pertronix ignitor in it along with a matching Pertronix coil. Install a set of NGK B6ES spark plugs too. For exhaust, have a 2" exhaust built with a turbo muffler so it's not too loud.

 

Other than that, unless you have a couple grand to spend, I'd leave it stock.

 

Hainz had good advice about the oil pan and pickup. Use the L16 parts.

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55 minutes ago, Stoffregen Motorsports said:

What head is on the L20B? Square port heads are better than round port heads.

 

I would keep the L16 exhaust and intake manifolds, get a Weber 32/36 DGV, have the original L16 distributor re-curved and install a Pertronix ignitor in it along with a matching Pertronix coil. Install a set of NGK B6ES spark plugs too. For exhaust, have a 2" exhaust built with a turbo muffler so it's not too loud.

 

Other than that, unless you have a couple grand to spend, I'd leave it stock.

 

Hainz had good advice about the oil pan and pickup. Use the L16 parts.

Hi, it’s a A87 head. I currently have a l16 not a l20.  Price range is about 3-4,000. Would you recommend the z22 with the l20 head? Or what would you do with that budget. I have a 200sx 5 speed currently. Thanks for the advice! 

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1 hour ago, banzai510(hainz) said:

key is clutch set up. what size flywheel you have!!!!!!!!!200 or 225mm this tetermines the T?O bearing set up.

simple is get a 200mm flywheel for a L20 seden as they had the 200mm and you can use your 510 T/O bearing demensions(just get new and get a roadsterclutch.

 

use the 510 oil pan and oil pick up.

keep the 510 exhaust.

 

that's about it

I am not sure of the size of flywheel. Thank you for the info! 

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You can open a can of worms for 3-4K, but you can't really build a performance engine for that. You could start on the road to horsepower with the head. Have it (or another head) ported and install big valves, good valve springs and a nice cam. Then eventually, build yourself either a long rod Z20 bottom end or even a 2200 (which is a custom build entirely).

 

Dual carbs (Mikuni 44's or Weber 45's) and a good header with a 2.5" exhaust on your L20B with the good head and cam will make around 170 hp on pump gas. But carbs aren't cheap like they used to be. A Mikuni setup can set you back 3-4K easily. There is another brand of carbs that is gaining in popularity. OER carbs are similar to both Webers and Mikunis, but much cheaper.

 

For carbs, you could try Mike Malone in the Monterey, CA area. He restores and sells a lot of side draft Mikuni setups and his work is phenomenal. I can get you his contact info if you're interested.

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3 minutes ago, Stoffregen Motorsports said:

You can open a can of worms for 3-4K, but you can't really build a performance engine for that. You could start on the road to horsepower with the head. Have it (or another head) ported and install big valves, good valve springs and a nice cam. Then eventually, build yourself either a long rod Z20 bottom end or even a 2200 (which is a custom build entirely).

 

Dual carbs (Mikuni 44's or Weber 45's) and a good header with a 2.5" exhaust on your L20B with the good head and cam will make around 170 hp on pump gas. But carbs aren't cheap like they used to be. A Mikuni setup can set you back 3-4K easily. There is another brand of carbs that is gaining in popularity. OER carbs are similar to both Webers and Mikunis, but much cheaper.

 

For carbs, you could try Mike Malone in the Monterey, CA area. He restores and sells a lot of side draft Mikuni setups and his work is phenomenal. I can get you his contact info if you're interested.

I have send mikes work on FB. Great work. Thanks for the advice, do you build motors ? 

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I used to buildengines for a living, when I worked for Rebello Racing. Now I have my own business building and restoring vintage 4x4s.

 

Mike and I used to race 510s together. He's a really cool dude. And he comes across some pretty rare and valuable carb related stuff. All of his carbs come out looking out of the box new.

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