Blow through carbon kits ( turbo ish)

[Grimlid]

https://www.turbodatsun.com/Blow Through Carby Kit.htm

These blow through kits have always fascinated me . They look super cool and the mechanics are pretty straight forward.

  Just getting ready to rebuild my l20b . I talked myself out of a ka swap and into an old school all datsun build. (I get it , i will likely spend more to get a less efficient motor but it's what I'm doing. Plus I'll have a non electronic vehicle when the nukes drop and the emp Disables electronics lol)

Planning to do a semi performance upgrade when I rebuild the l20b and have been racking my brain over what kind of fuel delivery system to go woth (ie Dual side draft/ quadruple motorbike carns, fat downdraft ect....) I was likely gonna just put a downdraft on it to get it on the road while I decided.

 I have extra cash to mess around and wtf these look really neat and old school high performance. I do listen to those of greater knowdge than I so I'm interested to know if anyone has any info or experience on how these blow through carby sets really work.

Assumably im gonna want to beef up big time on the rebuild to not roach the motor or is it even possible for an l series motor to survive this level of abuse?

 Perhaps I will leave my l16 in and test the fucking kit on that and see what happens?

 Any thoughts and opinions appreciated. 

Thanks

Grimlid

[datzenmike]

The blow through 'kit' does not include the turbo or the exhaust manifold. The turbo kit shown is for a Z24 engine.

[Stoffregen Motorsports]

If you wanted to add boost to a stock L series motor, I would say no more than a couple pounds of boost. You'll break rings and crack pistons.

[datzenmike]

11 hours ago, datzenmike said:

 

The turbo kit shown is for a Z24 engine.

So unless one is available you will have to make one for the L20B $$$$$

 

 

There were a few carburetor turbo engines back in the day, the Chrysler 2.2 and the Ford 2.3. Both used stock hypereutectec pistons, boost was limited to about 5-7* pounds and it would live all day at this. Beyond this if you want the engine to live you would need detonation control, mixture control, ignition retard under boost, forged pistons, proper ring gap is now critical, water meth injection, oil cooler, O ring the block.... well as you can see you have to pay to play.

 

*In theory 1/2 bar would produce as much as 50% more power

 

 

What about an AMR500 supercharger? A 3 to 1 pulley would produce 50% more air so about 7.5 PSI and a lot simpler to rig up.

[Icehouse]

The problem with boosting an L series is there isn't that many exhaust studs.  They are fun but an ongoing project to keep them running.  I've done a few and learned my lesson.  A super charger might be a better be for reliability.  

[Stoffregen Motorsports]

I suppose one could drill the head for more studs and then make custom flanges for the exhaust and intake, but who wants to go to all that trouble?

[datzenmike]

Do like the KA intakes and run a strut down to an engine bracket to triangulate it.

[Grimlid]

On 3/2/2024 at 10:34 AM, datzenmike said:

So unless one is available you will have to make one for the L20B $$$$$

 

 

There were a few carburetor turbo engines back in the day, the Chrysler 2.2 and the Ford 2.3. Both used stock hypereutectec pistons, boost was limited to about 5-7* pounds and it would live all day at this. Beyond this if you want the engine to live you would need detonation control, mixture control, ignition retard under boost, forged pistons, proper ring gap is now critical, water meth injection, oil cooler, O ring the block.... well as you can see you have to pay to play.

 

*In theory 1/2 bar would produce as much as 50% more power

 

 

What about an AMR500 supercharger? A 3 to 1 pulley would produce 50% more air so about 7.5 PSI and a lot simpler to rig up.

Thanks for the info. The ad only shows the z series in pics but sells L series stuff. Mostly curious as Im rebuilding my L20 and planning on doing it well but can even  high end build stand up the stresses of something like this? 

the supercharger is cool idea especially since you can order them easily. Time to do some research. the amazon link to amr500 states 30 to 50 hp increase which is a nice # for me.

Thanks Mike

[datzenmike]

The L20B has 5 main bearings and can handle any load. Kieth Law has a 250 RWHP L20B that was running for about 15 years and is only now being rebuilt.

 

Can you guess which main bearing is for the L20B and which is for the 150 hp KA24E???? The L series bearing is on the left. That's a lot of support.

 

HP increase is a function of how fast you spin it. The AMR500 displaces 500cc. To fire all four cylinders the L20B must rotate two full turns so the AMR500 has only moved 1,000 cc or half of what's needed. Arranging a 2 to 1 drive only doubles this to 2,000cc. A 3 to 1 ratio would move 3,000cc or 50% more air and cramming that into a 2,000cc engine would produce about 1/2bar or 7.5PSI. Now here's the problem... the AMR500 is limited to 15,000 RPMs??? so at 3 to 1 it would be wise to not rev much over 5,000 RPMs on the engine. 7.5 PSI and 5,000 RPMs is easy for a relatively stock L20B. 

 

A 2 liter engine is about the upper limit for an AMR500.

[Stoffregen Motorsports]

An L20B with stock rods, ARP rod bolts and forged pistons can handle 250hp without breaking anything.

[Grimlid]

Thanks Mike and Stoffregen.

I have too many effin options . I've got a KADE with everything needed to swap (collected for a few years including rad, crossmember , can am box ect...,) I picked up an l20b and an l18 at Tycotts house cleaning at his shop. both need a rebuild and fuel delivery system . Ive got a r180 diff, 240z 5spd and all the necessities (flywheel, clutch , bell housing ect)....Ive got a mechanic and shop to do the hard work. Ive been collecting for years.

Ive been doing nothing but work up north 250 hours a month for the last 15 years so Ive got the money. I quit my job so I have time (not used to either). Just cant effin decide what angle to go.....

traditional (l20b) or comfortable (efi ka24).

You boys clearly know your L20b and KAs....... how many hp can I get from dual side draft with a 4000$ rebuilt L20b running 94 octane? would if be even close to the 140 hp I will get from the KA minus emission controls?

This has actually been keeping me up at night .....Ive googled it but seriously reading everything from L20b max at 120 hp  to max at 200hp (natural aspirated).

 

[datzenmike]

There were no 240z 5 speeds. The earliest was the '77 280z model year as an option. If it has this cover plate and vent with 6 bolts, it's a 71B 4 speed that was introduced in '72 to replace the earlier 71A. Naturally the later 71B 5 speed could have been swapped in and it is the exact same transmission used in the 620 truck and 810/Maxima.

 

 

 

L18 stock about 83 hp side drafts 90 with cam 95- who knows but the more cam the less streetable.

L20B with side drafts maybe 100-105 with cam 120- who knows but the more cam the less streetable.

Z22 with L head side drafts and cam over 130. Byron has/had this. L head has smaller combustion chamber so 9.8 compression. He tried EFI and gained just a few hp. Made and cast his own intakes for the side drafts...

 

 

KA24DE stock efi 150 (can't see side drafts worth the bother except for the sound)

KA24E stock efi 145

VG30 stock 165

 

There are any amount of EFI delete videos for the KA engines and it won't add any HP to a KA. If you are running side drafts the EFI is gone anyway and the CAS can be gone also, just throw a matchbox on it. L20B making 140 is straining like hell to make 50% more while the KA makes more not even trying. The choice is obvious.

[SupDoc]

This guy was designing a rotex supercharger kit that might be interesting. But hasn't updated the site in a while...

 

https://www.bossadesignengineering.com/products/rotrex-supercharger-kit

Edited March 6 by SupDoc

[datzenmike]

Basically a Pro-Charger.

[Stoffregen Motorsports]

16 hours ago, Grimlid said:

You boys clearly know your L20b and KAs....... how many hp can I get from dual side draft with a 4000$ rebuilt L20b running 94 octane? would if be even close to the 140 hp I will get from the KA minus emission controls?

This has actually been keeping me up at night .....Ive googled it but seriously reading everything from L20b max at 120 hp  to max at 200hp (natural aspirated).

 

There's a lot of misinformation out there, or to be more specific, old information about how to get HP from a Datsun.

 

$4000 put into an L20B will get you a very good engine, but that's assuming you have carburetors and a manifold. If you want to buy 44phh Mikunis and a good intake, you're going to spend $2500-$3500 right there. Weber DCOEs are good, but not as authentic, and they are a lot less money. OER carbs are kind of new to the marketplace and cost about $400 each. And there are six or seven different side draft manifolds to choose from. Rebello and Ermish are selling a billet BRE copy intake for $600. That's your best bet.

 

If you had carbs and all that money could go into the motor, you could build a "2200" and make around 200hp at the flywheel.

 

The KA motors I built were for SCCA GT3 racing. Someone else here may know what kind of HP you can get with a KA street motor. I do remember we built a KA24E street motor for Ralph Kenyon (forget what his name is here on Ratsun) many many years ago. If I recall, it was around 200hp with stock-ish EFI.

[Grimlid]

6 hours ago, Stoffregen Motorsports said:

There's a lot of misinformation out there, or to be more specific, old information about how to get HP from a Datsun.

 

$4000 put into an L20B will get you a very good engine, but that's assuming you have carburetors and a manifold. If you want to buy 44phh Mikunis and a good intake, you're going to spend $2500-$3500 right there. Weber DCOEs are good, but not as authentic, and they are a lot less money. OER carbs are kind of new to the marketplace and cost about $400 each. And there are six or seven different side draft manifolds to choose from. Rebello and Ermish are selling a billet BRE copy intake for $600. That's your best bet.

 

If you had carbs and all that money could go into the motor, you could build a "2200" and make around 200hp at the flywheel.

 

The KA motors I built were for SCCA GT3 racing. Someone else here may know what kind of HP you can get with a KA street motor. I do remember we built a KA24E street motor for Ralph Kenyon (forget what his name is here on Ratsun) many many years ago. If I recall, it was around 200hp with stock-ish EFI.

Thanks Stoffregen,

 Also thanks for the hook up on the OER carbs that's a pretty interesting site to add to the options list.

 Im probably gonna make a separate thread for carburetor opinions. Im likely going to go with dual side draft  weber for ease of about everything (I found multiple kits online which have everything including the manifold for around 1500$ plus shipping. I also located a guy selling a used set of SU carbs and manifold (half the price) but carbs would at least need to be jetted if not rebuilt (they are off a 1600 0r  18000 sss (he wasn't sure which)) but from what I'M hearing the SU carb will never get what a weber can and definitely not come close to a mikuni or some of the other higher end units. Some people go as far as saying the SU is useless? I've only ever had a 32/26 weber since I bought my car with the kit and had it jetted and cleaned up by Paul Silva 5 years ago.

 The dual SU carbs look so cool though its tough not to like the appearance for me.....but if the performance is that bad obviously why bother.

Edited March 6 by Grimlid
typo and additional info

[Stoffregen Motorsports]

Datsun Hitachi SU carbs are not going to give you anywhere near the horsepower that dual side drafts will. Even a DGV will make more power than dual SUs. They may be cool looking but if I had to choose, I'd go with the DGV.

 

DCOE carbs are fine, but don't have as many tuning options as Mikuni/Solex carbs.  They will work absolutely fine, but if tuning for perfection is your thing, 44PHH carbs are best.

[EDM620]

On 3/5/2024 at 7:04 PM, SupDoc said:

This guy was designing a rotex supercharger kit that might be interesting. But hasn't updated the site in a while...

I've always been a fan of super over turbo boost.