Miss Piggy Resto

My front springs aren't as bad as yours was but still needs pulling out and cleaning.
The van came with the l20b motor and BW35 auto the motor sits in its datsun cradle with brackets attached and bolted to the chassis rails
and because it has a forward drop sump won't clear the steering arms, the motor is quite tall and the top of the carbie is pretty close to the engine lid
http://i1281.photobucket.com/albums/a508/mowoodie/Commer/WP_000119_zps831e258f.jpg
http://i1281.photobucket.com/albums/a508/mowoodie/Commer/WP_000120_zpsdf20fc92.jpg
http://i1281.photobucket.com/albums/a508/mowoodie/Commer/WP_000158_zps7fbc4d00.jpg
http://i1281.photobucket.com/albums/a508/mowoodie/Commer/WP_000170_zps2b4c6718.jpg
This one shows the cradle

Such is Life
 
I know these motors very well from my Datsun 1600 Rally car I had in the 80's. In case you didn't know, the 3 main versions of the 4 cylinder L series motors all have different sumps. The L16 has the deepest part of the sump at the rear of the motor. The L18 has the deepest part of the sump about 3/4 to the rear. The L20B has the deepest part of the sump at the front of the motor. The are all interchangeable, you just need to have the sump oil pick up and matching sump. In my rally car I had an L20B with L16 sump and pick up. Either of the L16 or L18 sumps will enable you to move the motor forward and or lower if you need to. By the way, I'm not sure about the sump on the L16 Stanza's, I didn't have much to do with them back then and I already had the L16 motor to pinch bits off.

I will need to check this out with my Z24 motor. All those steering arms are a pain. I think the base of the Z22/24 block could be a little wider for the long stroke crankshaft. I recall people needing to grind out the L20B block when fitting the Z22/24 cranks for bigger capacity. Yes the crankshaft are a straight swap. The Z24 block is pretty much the same as the L20b, the main difference is the head and front timing cover. I have read of guys now using Z22 or Z24 blocks with L Series heads and timing covers. A lot of interchange ability, that's why the Datsun 1600 was such a popular rally car in Australia

The standard carb on the L20b was pretty ordinary and always seemed to have a flat spot when turning right in a hurry. The SSS twin Su's and manifold, still often advertised on Ebay, bolt straight on and make the world of difference, though they could be a little wide for the engine bay, you would need to check.

With all that room in front of the motor you could fit 2 or even 3 radiators, which would be handy considering the hot weather we've been having lately

Cheers Stephen

Cheers
Stephen
 
My motor is not in the car at the moment but i think the top of the motor was really close to the under side of the engine lid giving me little room to raise it.
Thanks for that info on the sumps very interesting.
i've had the original carb recoed months ago in readyness for install and have finished welding the back firewall and don't really want to redo it at this stage.
I just finished that dreaded job of decruding the underneath , grinding, washing , blowing out a bucket full of dirt out of the chassis rails then brushing 2 coats of body deadener and filling the rails with fish oil, what a b---h of a job, now it's leaking excess fish oil everywhere.
Stephen you might know about the l4n71b 4 speed auto boxes i'm thinking about putting this behind the l20b i found one on gumtree out of a RB30 dunny door and was wondering if this would fit, maybe changing the bell housings over ?
I know the came out in the nissan maxima in 84, i'd like to get that extra gear for cruising.
you seem to be good at maths if i run the l20b + 4 speed auto + 205/65r/15 tyres what would this equate to.
Cheers Frank


Such is Life
 
Engine height is a problem, especially with OHC versions. I went for the Z series motor as they have a lowered/swept down inlet manifoldas used on the Nissan Urvan. It drops the height of the carbie considerably and the rocker cover height seems lower than the L20B. The old E20/Urvan used the H series motor and the Vanette used the A series OHV. I don't recall a Nissan Datsun van using the L series motor so an inlet manifold swap option might not exist. There are fuel injection manifolds around for your motor, but are scarce and often very expensive, then you have to make it work, though would be good if used with an LPG conversion.

Not experienced with autos. Almost 36 years on the road and never had an auto. The best place to get that sort of information is from the Australian Datsun web OZDAT http://www.ozdat.com/. Some very good information there on Datsun/Nissan cars and mods. Someone there will probably know or be able to point you in the right direction.

Regarding your road speed question, I have an Excel spread sheet that works it all out, I down loaded years ago from a Datsun website. I wrote a computer program in 1981 when I was supposed to computer studies while doing an Engineering Certificate, which did the same and used it often for setting up gearing on the rally car. This Spread sheet is great, you can compare tyre sizes to get the same rolling diameter. I have just used it again to check the tyre size equivalent to the 185R14's fitted to my Mitsubishi Express, I picked up a set of 225/50 x 16" and was surprised that they are slightly smaller in diameter which equated to reduction of 2 mph (3.22 kph) at 3000 rpm in 5th.

It's hours of fun and a very handy tool for anyone swapping Wheel/Tyres, gearbox/diff ratios. You will need to have the following information

Wheel size Width, profile and rim diameter, diff ratio(has provision for 3 so you can compare results), gear ratios and select the rpm you desire. It gives you speed at given RPM for the primary tyre selected with for 3 different diff ratios and a graph of speed in all gears to the select rpm, and suitable for up to 6 speed gearboxes

Also has a second page for calculating compression ratio but have never used it.

Would be good if it could be added to the download page for all to access. I can Email it to you so you can have a look, there are quite a few of these around these days if you have a search on the web. I'm used to this one and it does what I need. This one is in Miles per hour, which has never worried me as I grew up on the change to metric and all my early cars had old MPH speedos.

I also found one recently for motorcycles http://www.gearingcommander.com/ where you can draw on their data base of motorcycles then change Tyre,sprocket sizes etc to see the effect it has.

Cheers Stephen
 
OK what a wealth of info you are, i'll try and find out what the ratios are in the 4 speed in that web site you gave me and i'll let you know
Cheers

Such is Life
 
Found this about your proposed auto gearbox on another Datsun website, also a very good source if Datsun modification informationhttp://datsun1200.com/modules/newbb/viewtopic.php?topic_id=39732and
http://datsun1200.com/modules/mediawiki/index.php?title=L4N71B_Swap

Regarding expected road speeds I have had a play and come up with the following

I found out the auto box is 3rd gear 1:1 and 4th gear O/D 0.686:1. Using the Humber 4.55:1 diff with 205/65 x 15 tyres your road speeds equate to

2000RPM 33mph (53kph)in 4th and 48mph (77kph) in 4th.

2500RPM 41mph (66kph)in 4th and 60mph (97kph) in 4th.

3000RPM 49mph (79kph)in 4th and 71mph (114kph) in 4th.

3500RPM 57mph (92kph)in 4th and 83mph (134kph) in 4th.

Using the same wheel/and gear ratios, but using the existing Commer 5.125:1 diff the figures are as follows

2000RPM 29mph (47kph)in 4th and 42mph (68kph) in 4th.

2500RPM 36mph (58kph)in 4th and 53mph (85kph) in 4th.

3000RPM 43mph (69kph)in 4th and 63mph (101kph) in 4th.

3500RPM 51mph (82kph)in 4th and 74mph (119kph) in 4th.

To me using the standard Commer diff would be the better option as I think the L20B motor would struggle with such tall gearing using the Humber diff. From experience this motor with a weber, extractors and a very mild cam are happy running around 3000-3500 I the higher gears.

There could be another version of the proposed gear box with a less tall alternative 4th gear ratio which could work well with the taller Humber diff ratio.

Other alternative is you could go to lower 60 or even 50 profile tyres using the tall Humber diff.

The call is yours, but shows what a handy tool the spread sheet is. Can save a lot of work, as no swapping and changing things to see what effect it has, you get much closer to what your desire first time.

As the sun has been out, I expect you have been getting more done on the van. I'm heading out to the shed to make some space so I can hopefully get things moving again.

Cheers
Stephen
 
The diff ratio in my van was 5.65:1 as i counted out the crown and pinion.
Ive since been hunting around the local wreckers here and in brisbane i've found some but they are off the rb30 6cyl cars
and the vibe i'm getting is that the BW35 would be the better choice for that motor not sure anymore.
The BW35 ratios are 1st - 2.393
2nd - 1.450
3rd - 1.000
with your calculator would this be a better fit.

I've had a bit of time off with a back issue so getting under the van has had to wait for a while.
It's a bugger when you want to down and dirty but can't so i just keep making lists of stuff to do.

I have fish oiled the inner subframe and between the hidden panels and body deadened 3/4 of the under floor.

Next job take the front end out for cleaning and i've made 2 of those patented spring clamps of yours,then refit the fuel tank and springs
as well as fitting shocky mounts.



Such is Life
 
Using the same 205/65 x 15 tyres with the BW35 Ratios and Humber 4.55:1 diff you get the following results

2000 RPM 14mph (23kph)in 1st 23mph(37kph)in 2nd and 33 mph (53kph) in 3rd.

2500RPM 17mph (27kph)in 1st 28mph(45kph)in 2nd and 41mph (66kph) in 3rd.

3000RPM 20mph (32kph)in 1st 34mph(55kph)in 2nd and 49mph (79kph) in 3rd.

3500RPM 24mph (39kph)in 1st 39mph(63kph)in 2nd and 57mph (92kph) in 3rd.

4000RPM 24mph (39kph)in 1st 39mph(63kph)in 2nd and 65mph (105kph) in 3rd.

To me the above results confirm you definitely need the overdrive 4th gear or a higher diff ratio.

As the L20B block is similar to the 2.0, 2.2 & 2.4 litre Z series blocks, I wonder if the auto out of a Navara or Urvan will bolt up. Pretty sure they had 4 speed autos and there should be plenty of old Navaras around the wreckers. Will have a search and see if I can confirm one way or the other.

Cheers
Stephen
 
This is excellent stuff, thanks for sharing[8D]

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Member of the Non-Facebook Club
 
Stephen i really appreciate all the research you are doing and i sort of thought i needed a 4 speed but not knowing which way to go,
awsome mate Thanks

Such is Life
 
Hi guys here are some recent photos to gauck at

[/IMG]
Before cleaning

WP_000651_zps11fdf4fe.jpg

Before cleaning

WP_000696_zpsd775588c.jpg

After with 2 coats of body deadner and cavitys filled with fisholine

WP_000695_zps97ea5295.jpg

WP_000698_zpse363cc63.jpg

Fuel tank ready to go back in

WP_000693_zps27614221.jpg

Humber super snipe rear brake drum sitting neatly in the rim with only a few mil of play i'll be using these eventually

WP_000691_zps1d717e81.jpg

this has the Commer rear brake drums quite a bit of difference

WP_000634_zpsbbc8d792.jpg

Commer diff on the left at 5.56:1 and humber on the left at 4.55:1

WP_000642_zpsc78c36ad.jpg

Humber wheel note no breather holes

WP_000639_zps7beb42e2.jpg

Commer wheels with breather holes the humber brake drums just fit between them with a few mil play


Such is Life
 
Wow - what a difference a wire brush, a couple of months, a knackered back a slow decent into madness because all of the time spent alone on your back - makes[8D]

41fa30c8-22ce-43e8-bd12-188475a80292.jpg

Member of the Non-Facebook Club
 
Nice job, coming along well [8D]

4650583641_dba2503b41_o.jpg

"You,re only supposed to blow the bloody SLIDING doors off"
Founder of the 6 speed club
 
The man is on fire, talk about getting on with it. I hang my head in shame.

Regarding the diffs, description a little wobbly, I am assuming the bigger diff is the Humber unit on the right. Seems an interesting diff centre, as most are open like the picture on the right and you can see the inner gears as in the picture to the left. Closed diff centres that I have seen that are enclosed like the right hand one have been Limited Slip Diffs. It would seem hard for oil to get in there to lubricate the inner diff gears, where as an LSD is packed with clutch plates and diaphragm springs. Is the centre totally enclosed or is it further around and cannot be seen in the picture.

Cheers Stephen
 
Had a quick hunt on the web and found this comparison that shows what I mean



This is the diff type I used in my Datsun 1600 Rally car years ago, it is called an R180 and comes from the Z and K series 6 cylinder Datsun's of the day, stronger than the std R160 fitted to the car and an easy swap with LSD centres more easily available. The one on the left is the standard "open" type diff while the one on the right is fitted with an LSD Centre. The diff I fitted to my van, from a Nissan Navara has a LSD and again looks like the diff on the right.

Cheers Stephen
 
Humber and Commer used interchangeable parts so the diffs were the same bar the crown and pinion and much bigger drums, i'll check out what you said about it maybe a LSD.
Today i refitted the fuel tank and rear springs, i had the springs reset an extra 1 1/2in but after refitting them it looks like the back end might be quite high, it might be ok it'll give me a little more room to get the wheel off after fitting the bigger drums.


Such is Life
 
went to pick up the humber disc today and took my wheel to try before i buy they fitted
into the rim but the caliper piston hit the bulges in the rim and also rubbed against the flat
has anyone found this as well and if so what is the solution, i thought this was a straight swap

Such is Life
 
You could fit thin spacers. I think Martin M had the same problem, he modified the wheel slightly with an angle grinder - just took the edge off the breather bulges. Will the Humber wheels fit OK?

41fa30c8-22ce-43e8-bd12-188475a80292.jpg

Member of the Non-Facebook Club
 
All has been going slow lately i've removed the front end cleaned, and painted ordered new wheel cylinders and have tossing up weather to keep the original brakes or change to humber super snipe.
Then one the long weekend i had my 53 Morris oxford traveller book in for the cooly rock festival at coolangatta, before i went i had water pump issues which i fixed a couple of days before and drove it around
for couple of days to make sure it was good -- all good, so thursday arvo all packed up headed off from Caloundra towards Brisbane and stopped at the first BP servo hopped out the car to see all my coolant running down the road, yes the pump s++t itself so a quick RACQ tow back home swap cars and off to the show with out my pride and joy---TOTALLY pissed off.
But wow what a weekend 1300 customs and classics so i've now been thinking going down the V6--V8 road, now even more confussed.
So how are you going with the 2.4 convert?







Such is Life
 
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