Home Built Z 'full Video Build'

[HomeBuiltByJeff]

Good work Jeff. Another way to clean up the rust areas under the bonnet skin where you removed the section is to blast it outside with a hand held garnet gun. You end up covered in garnet but it removes all the rust and you can then hit it with zinc gal. To reduce warpage when you are doing large flat sections, just do it one tack at a time and move around the patch using an air gun to cool it down, it looked like you had run a bead along the join, it should be a series of spots. I would recommend James at MIA for engines, but it wouldn't be home built then!

I did tack and cool, tack and cool. I have done it a multitude of different ways, and from my (admittedly limited) experience, if you are doing a large repair on a flat panel, it is always going to warp a bit. I did run some short beads in sections, as often even at the lowest setting, the tacks would blow through. It was easier with a bit of movement, to spread the heat and stop the blow through. The beads were still probably only 2 second welds on one spot, cool, move to the other end for the next one and so on. I will be doing plenty more of that sort of welding in the next few weeks, so I should hopefully be able to get some footage instead of stuffing up the camera again    

[gav240z]

With the heat shrinking it looked like you put quite a bit of heat into the panel, you don't need to add a lot of heat, it's literally on for a couple of seconds and then off again. Better to do lots of small heat shrinks than big ones! Good that it seems to have fixed it for you though all the same.

 

Not much you can do about the surface rust under the skin of the bonnet, when you cannot access that area. You could try dipping the panel and converting rust that way, but if you're going to use fish oil make sure you do it after you're finished painting (not before) as it can lead to "fish eyes" in the paint etc..

 

By the way is the motor head a P90a? I'll bet it had compression but you need to work on your guns and turn the motor with more effort . It probably would have run ok, but worth re-lapping valves etc.. cleaning it up from all that carbon build up and doing something about the camshaft. It's probably sat for many years like that.

[HomeBuiltByJeff]

With the heat shrinking it looked like you put quite a bit of heat into the panel, you don't need to add a lot of heat, it's literally on for a couple of seconds and then off again. Better to do lots of small heat shrinks than big ones! Good that it seems to have fixed it for you though all the same.

 

Not much you can do about the surface rust under the skin of the bonnet, when you cannot access that area. You could try dipping the panel and converting rust that way, but if you're going to use fish oil make sure you do it after you're finished painting (not before) as it can lead to "fish eyes" in the paint etc..

 

By the way is the motor head a P90a? I'll bet it had compression but you need to work on your guns and turn the motor with more effort . It probably would have run ok, but worth re-lapping valves etc.. cleaning it up from all that carbon build up and doing something about the camshaft. It's probably sat for many years like that.

Good to know with the heat levels. I went off of some dodgy backyard youtube video, as I couldn't find anything more current. I will keep that in mind for the rest of the repairs.

 

The head is a 90a. What one of the YouTube comments mentioned was that as it has hydraulic lifters, it would need oil pressure to get full tension on the valves.

 

My plan now is to do a full rebuild. I just need to think about how far I want to go. I at least want to put in a mild cam. Basically I am looking to do something that is still streetable, but getting a bit more out of it. I plan on keeping it naturally aspirated (love that noise  ), with some sort of triple carbs (brand to be determined).

 

Any suggestions are more than welcome. I am looking for a nice build, that I can do myself, and that others can reasonably replicate. 

[gav240z]

The head is a 90a. What one of the YouTube comments mentioned was that as it has hydraulic lifters, it would need oil pressure to get full tension on the valves.

 

90a or P90a? I've never heard of a 90a before. If it's a P90a then yes they had hydraulic lifters but apparently they can go bad and you can replace them with the older style lifters relatively easily I believe.

 

As for suggestions on the engine, have you read this thread yet?

http://www.viczcar.com/forum/topic/1738-l26-refresh-thought-id-share-the-results/

 

I like it because it's very methodical in it's approach, but yields excellent results and drivability. It shouldn't break the bank.

[HomeBuiltByJeff]

It is a P90a sorry. I will have to check the lifters to see how they are.

 

I will check out that thread now, thanks.

[Andrew_L26]

I'd just like to add that not all P90a heads had hydraulic lifters from my knowledge.

Loving the build!

 

Andrew

[HomeBuiltByJeff]

I'd just like to add that not all P90a heads had hydraulic lifters from my knowledge.

Loving the build!

 

Andrew

Ok, that is something I have to look into then. I did read on one site that said that was the difference between the P90 and the P90a, but just because it is on the internet, definitely doesn't mean it is true 

[gav240z]

It is a P90a sorry. I will have to check the lifters to see how they are.

 

I will check out that thread now, thanks.

 

By the way this might be useful to you.

 

[HomeBuiltByJeff]

This week I tear down the bottom end of my L28 and repair some rust holes in my front cowl.

 

[gav240z]

Well the fender repair was good, the cowl panel... hmmm not so much lol..

 

I have a spare cowl panel here that was given to me, it is also warped because of someone using a mig welder (so the whole panel has twisted) but that area that looks less than ideal on your 1 (passenger side upper corner) could probably be cut out and used.

 

Let me know if you want it? I have good cowl panels on my cars (no previous owners did poor repair work on them). So I don't really have a use for it other than a spare.

[HomeBuiltByJeff]

Well the fender repair was good, the cowl panel... hmmm not so much lol..

 

I have a spare cowl panel here that was given to me, it is also warped because of someone using a mig welder (so the whole panel has twisted) but that area that looks less than ideal on your 1 (passenger side upper corner) could probably be cut out and used.

 

Let me know if you want it? I have good cowl panels on my cars (no previous owners did poor repair work on them). So I don't really have a use for it other than a spare.

Sweet. I will see how it goes, when I have to start lining everything up properly. If it is too far out I will hit you up. What I do need is an old dead engine someone has lying around, as mine was stripped, but didn't come with all of the nuts and bolts. They are not easy to replace.

[gav240z]

I believe many fasteners are still available from Nissan particularly those for the engine as the L-series was used for so long on so many cars.

[AndBir]

Pity they are not in NSW however these cowl panels look in good shape should you find you need a straight one.

 

https://www.gumtree.com.au/s-ad/berwick/auto-body-parts/datsun-240z-260z-scuttle-cowl-panels-/1162776558

[MATTY]

also don't know if anyone's mentioned it (well not what i could see) grinding back your welds can also distort the panel if the grinder is in the same spot too long best to try to keep grinding evenly across the welded surface.

[HomeBuiltByJeff]

also don't know if anyone's mentioned it (well not what i could see) grinding back your welds can also distort the panel if the grinder is in the same spot too long best to try to keep grinding evenly across the welded surface.

I actually think the grinder caused more heat into the panel and more warping than the welder did. I am biting the bullet and getting a 5 inch grinder this week and also some super coarse discs. As someone commented on Facebook, the bigger the disc and the faster it takes away material, the less heat that is transferred.

[MATTY]

I actually think the grinder caused more heat into the panel and more warping than the welder did. I am biting the bullet and getting a 5 inch grinder this week and also some super coarse discs. As someone commented on Facebook, the bigger the disc and the faster it takes away material, the less heat that is transferred.

i use fibre backed grinding discs for the majority of any grinding work i do. i find they are easier to use and come in a variety of grits as well giving a better finish than a flap disc or normal grinding disc

[HomeBuiltByJeff]

i use fibre backed grinding discs for the majority of any grinding work i do. i find they are easier to use and come in a variety of grits as well giving a better finish than a flap disc or normal grinding disc

I have not seen them? I know most grinding discs I have used have a mesh grid construction, is that what you are refering to?

[MATTY]

I have not seen them? I know most grinding discs I have used have a mesh grid construction, is that what you are refering to?

theses are pretty much like a sanding disc off a orbital sander but designed for a grinder with a nyon backing plate for a lack of a better description and look like this

 

 

few grinding brands stock their own versions of them but. They are also good because you can use the whole surface area of the disc unlike the conventional grinding disc or flap dics

[HomeBuiltByJeff]

Interesting. I wear out the solid grinding discs pretty fast when I am grinding back welds. Do these last? It looks like sandpaper to me, and I went through half of a flap disc in 10 mins today?

[MATTY]

Interesting. I wear out the solid grinding discs pretty fast when I am grinding back welds. Do these last? It looks like sandpaper to me, and I went through half of a flap disc in 10 mins today?

for a 5'' grinder depending on the grit and angle you grind on they don't last a longer than the normal grinding disc. strange that you're going through grinding discs like that now, that for a 4" or a 5" grinder?? a flap disc is more of a finishing disc and not designed for removing a great deal of material. id prefer the fibre backed discs any day of the week personaly and have been a favorite in most workshops worked in. might be worth trying them out for your self and see what you think but

[HomeBuiltByJeff]

Up to now I have been using a 4" grinder on the welds and, probably due to my birdsnest welding, there is generally a lot to grind back  

[HomeBuiltByJeff]

This week I stripped down my P90a head to see what I am working with. I also tackled my most difficult rust repairs to date.

 

[AndBir]

Looks like they did a very rough patch up job, this is what the inside of the lower rear double skinned section of the front guards is meant to look like (including "period" surface rust) - so you got it right with your opening:

 

 

Water draining down from the windscreen cowl flows down to this area and through the double skinned section and this does block up especially when the rubber seal on the panel breaks down allowing dirt etc. flicked up be the wheels to enter this area - not a good design.

Edited October 20, 2017 by AndBir

[gav240z]

I mentioned on the Youtube channel, but I think some P90A's had solid lifters. So you may not need to swap your ones over.

[HomeBuiltByJeff]

Looks like they did a very rough patch up job, this is what the inside of the lower rear double skinned section of the front guards is meant to look like (including "period" surface rust) - so you got it right with your opening:

 

IMG_2946.JPG

 

Water draining down from the windscreen cowl flows down to this area and through the double skinned section and this does block up especially when the rubber seal on the panel breaks down allowing dirt etc. flicked up be the wheels to enter this area - not a good design.

Thanks for that. Mine were way too far gone to have any idea of what they were originally suppose to be like. Looks like I wasn't far off the mark, I just made mine a bit short.

 

I mentioned on the Youtube channel, but I think some P90A's had solid lifters. So you may not need to swap your ones over.

Yeah, it looks like I got lucky