Rebuilding my L20B

[flatcat19]

Flattops and open head in an L20B will do just fine.

 

 

Easy enough build. Only real outlet is Machi e the block to match the pistons(never have the block bored without the pistons. Do t work with a machine shop that wont match.) And whatever you end up doing with the head.

 

Everything can be done in your garage with basic tools.

[flatcat19]

And, get this....

 

 

https://www.amazon.com/gp/aw/d/1931128030/ref=mp_s_a_1_1?ie=UTF8&qid=1494093696&sr=8-1&pi=AC_SX236_SY340_FMwebp_QL65&keywords=datsun+book&dpPl=1&dpID=61XQ92jjQ1L&ref=plSrch

[banzai510(hainz)]

your killing me!!!!!!!!!!!!

 

just buy that 38/38 and bolt it on today if you have a L20

[ErickwithnoK]

your killing me!!!!!!!!!!!!

 

just buy that 38/38 and bolt it on today if you have a L20

 

That's no fun! It's also way too cheap. 

 

Can't you see I'm trying to spend money and time for minimal gains?

[ErickwithnoK]

Flattops and open head in an L20B will do just fine.

 

 

Easy enough build. Only real outlet is Machi e the block to match the pistons(never have the block bored without the pistons. Do t work with a machine shop that wont match.) And whatever you end up doing with the head.

 

Everything can be done in your garage with basic tools.

 

And, get this....

 

 

https://www.amazon.com/gp/aw/d/1931128030/ref=mp_s_a_1_1?ie=UTF8&qid=1494093696&sr=8-1&pi=AC_SX236_SY340_FMwebp_QL65&keywords=datsun+book&dpPl=1&dpID=61XQ92jjQ1L&ref=plSrch

 

Thanks. 

 

Also, I'm halfway through that book right now haha. Plan to re read it alongside my shop manual for the teardown/build.

[racerx]

So what is the budget for said build

[Crashtd420]

This book is real good to.... might be a good read for you... has info not in the rebuild book....

[ErickwithnoK]

So what is the budget for said build

 

Tentatively, 2K. I will spend as little as possible but whatever is necessary until it gets rediculous. Which it probably will.

[banzai510(hainz)]

I have a semi built L16 w flattops and match ported the stock L16 intake with a Cam and run 38/38 and the HP gains were better esp when the 38 was on there. But went back to a 32/36 as the 38 went bad. personally the 460/260 Schneider cam I have in there should have came stock!!!!!!!!!!!!

Back then L16s were more plentiful as I was getting them near FREE.  The L18 is slightly better they SAY for higher RPM But really I cant tell the difference.

My 510 I rebuilt that motor as it was my first and it was pretty EZ but I have the block sent out with l18 pistonsinstalled. Machine shop cost money

Know ing wht I know now I would d L20s but a lot of them have a crack in the block and the motor builder wound garentee the block so  it depends if you want to risk it. Most time people don't know they are cracked

L20s are counter weeited while the Z motor are not.

 

Dave that hangs with Frank and Icehouse(Jeff Hino he has a Z block with L head but flattops and has detonation proplems . To get the power you have to run High octane. Most Datsun guys are the cheapest MOFos around so it don't last long esp on HOT days To get most power you got to advance the dist but with low octane gas it will detonate and have issues and maybe head gasket issues also.

 

 

if anyting I would do l18 4cc dished pistons on a L20 but they seem to be drying up if you can find them.

 

 

so with amount of questions you have I think best to get a motor on the side and you can spend all the money you want then do a 1/2day drop in.

 

 

My prople now is finding a good machine shopt hat wont seem to fuck you over. Most time they say they have a 1 to 2 month drop off time to get it back and may be wrong . Ones in the know are good and is simple to them. I seem diffent lash pads installed cause the Chevy machine shop sinks the valves and are not right when you put a new cam in there and you trying to source different lash pads are these are getting harder to find also. Just cause they supply the lash pads still doesn't mean youll use that size. Its all base on a new perfect head.

 

So Im telling you from experience.

 

But you can do what you want. 

[ErickwithnoK]

This book is real good to.... might be a good read for you... has info not in the rebuild book....

 

I've got that one too  :thumbup:

 

Started it awhile ago and decided to read the rebuild book first to learn more about the motors as they are before learning how to modify them

[ErickwithnoK]

I have a semi built L16 w flattops and match ported the stock L16 intake with a Cam and run 38/38 and the HP gains were better esp when the 38 was on there. But went back to a 32/36 as the 38 went bad. personally the 460/260 Schneider cam I have in there should have came stock!!!!!!!!!!!!

Back then L16s were more plentiful as I was getting them near FREE.  The L18 is slightly better they SAY for higher RPM But really I cant tell the difference.

My 510 I rebuilt that motor as it was my first and it was pretty EZ but I have the block sent out with l18 pistonsinstalled. Machine shop cost money

Know ing wht I know now I would d L20s but a lot of them have a crack in the block and the motor builder wound garentee the block so  it depends if you want to risk it. Most time people don't know they are cracked

L20s are counter weeited while the Z motor are not.

 

Dave that hangs with Frank and Icehouse(Jeff Hino he has a Z block with L head but flattops and has detonation proplems . To get the power you have to run High octane. Most Datsun guys are the cheapest MOFos around so it don't last long esp on HOT days To get most power you got to advance the dist but with low octane gas it will detonate and have issues and maybe head gasket issues also.

 

 

if anyting I would do l18 4cc dished pistons on a L20 but they seem to be drying up if you can find them.

 

 

so with amount of questions you have I think best to get a motor on the side and you can spend all the money you want then do a 1/2day drop in.

 

 

My prople now is finding a good machine shopt hat wont seem to fuck you over. Most time they say they have a 1 to 2 month drop off time to get it back and may be wrong . Ones in the know are good and is simple to them. I seem diffent lash pads installed cause the Chevy machine shop sinks the valves and are not right when you put a new cam in there and you trying to source different lash pads are these are getting harder to find also. Just cause they supply the lash pads still doesn't mean youll use that size. Its all base on a new perfect head.

 

So Im telling you from experience.

 

But you can do what you want. 

 

I'd run l16's if they were free, too!

 

If the l18 pistons are 85mm I probably wouldn't go with them because I'll want a fresh bore for new pistons. 

 

The shop I plan to use is Drummond Automotive in southern Oregon, Bob Drummond has supposedly been doing Datsun motors for 30 years so I'll bet he's aware of these things. Hopefully by trusting the right people I won't be betting as much on my own experience, because I have 0 experience. 

 

And about the 38/38, that's probably what will end up happening. It's affordable and I can run my stock air cleaner which I love.

 

Thanks Hainz.

[banzai510(hainz)]

you have to modify the stock aircleaner  as thr carb adapter is taller and might cause it to hit the hood. they is a short 1.75 tall weber aircleaner but most come with the taller one

 

as for the l18pistons, most just buy the over size in 020/040/060 thou over. or just buy the stock 86mm.  but then one can have headgasket issues and need to FIND 87mm bore headgasket. As I seen the edge of the Felpros near the bore or the edge is right there.  I have spare 87mm Durapro head gaskets I got from Austriala

[ErickwithnoK]

you have to modify the stock aircleaner  as thr carb adapter is taller and might cause it to hit the hood. they is a short 1.75 tall weber aircleaner but most come with the taller one

 

as for the l18pistons, most just buy the over size in 020/040/060 thou over. or just buy the stock 86mm.  but then one can have headgasket issues and need to FIND 87mm bore headgasket. As I seen the edge of the Felpros near the bore or the edge is right there.  I have spare 87mm Durapro head gaskets I got from Austriala

 

Thanks for letting me know, I saw a thread awhile back about how to get the stock air cleaner to fit a weber, I'll have to dig that up!

 

If you bore an l20 block do you buy a custom head gasket or can you trim a 85mm headgasket to be a 86mm?

[racerx]

So about 2k to spend, how much go you expect to gain, from head work and new carb?

[racerx]

Meant how much horsepower you expect to gain?

[banzai510(hainz)]

find a Motorsport one head gasket. Ebay had one someone listed on here for 75$  88.5mm

[ErickwithnoK]

So about 2k to spend, how much go you expect to gain, from head work and new carb?

 

I don't expect any certain amount of HP gain. If I gain 5hp that's great, if 20 then I've greatly over achieved. I'm not going into it with horsepower goals, more to build an interesting motor that probably has a bit more power and was fun to build. 

[ErickwithnoK]

find a Motorsport one head gasket. Ebay had one someone listed on here for 75$  88.5mm

 

Sounds good.

 

So if the head gasket is a little bigger than the bore won't it cause a (very slight) loss of compression?

[racerx]

Very easy, if u want 5 hp, then advance your timing...done

[flatcat19]

You won't find L18 pistons. Not new at least. And finding any oversized...no way.

 

 

The ones you'll find say fit L18 and L20B, but are L20B dish.

[Soundline]

You know... there are old timers on here that are speaking from experience on the "build the engine on the stand" while leaving a running one in the truck.

 

It gives you perspective and it will help keep you interested in the build. For instance, I have a non-Datsun project that I recreationally drive. I have a completely done engine on a stand, ready to go in whenever. In the meantime I'm killing the stock engine learning how to properly drive the thing. So, I have the best of both worlds. I got to build the next level motor, and, I get to enjoy the vehicle so I don't burn out on the project.

 

I hear some of these guys take the running engines out of their Datsuns, for alternator changes... just to put some paint on them and show off how fancy poppa smurf blue they can be... all while having a bad ass project engine slowly maturing on the side.

[distributorguy]

Yes.  Avoid having a disabled vehicle sitting around - at all costs!  They get way too easy to ignore after you start stacking stuff on them.  

[datzenmike]

Yes, when your source of pleasure and enjoyment is down you tend to look elsewhere for it. I try to avoid down time to the point things don't get done. Posting progress here helps keep the momentum going.

[Stoffregen Motorsports]

Motivation is hard to come by on some projects.

 

Professionals say the best way to keep the project going is to do something on it every day. Even if it's just organizing parts or wiping it down.

[datzenmike]

Here's another. Go out and stand looking at it. Imagination is a muscle that develops with constant use. Look at it and imagine what you would like to do or have done with it. Take it apart in your head, think of every step needed. Imagine it higher or lower or faster or sounding right or with a 5 speed. Imagine port matching it or an electric fan, or 100 amp alternator, better carb, better seats.........