Where to go with unknown build ive acquired

[Elliott000]

 

I grabbed a 240 of my buddy who had plans for it but it then sat for like 10 years. The engine has been rebuilt and from what I've been told and can see, never run. Ill post what specs I know

 

P30 block, unkown as to 2.4 or 2.6, n42 head, unkown cam and valve train. Im going to mount it on my stand and take the pan off to measure bore and get an idea on con rods. Through the plug holes it appears the pistons are a dished type. Ive done work on a few v8's but never a l series or straight 6 in general. I'd like to know what avenue to go before committing to this motor. It's supposedly a 3 litre stroker. I have a brand new stage 4 cam that came with it aswell as triple Webbers and intake but according to the cam instructions I should have certain valve and rockers etc. Maybe let me know your thoughts aswell as if u know by appearance any part numbers for the rockers etc. First thing I noticed is a gap between the unloaded rocker and the cam? from my experience we set up for zero lash? Thanks

 

 

 

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Edited May 8, 2018 by Elliott000

[Elliott000]

[siteunseen]

The cold gap for setting the lash on these motors is .010" for the exhaust and .008" for the intakes.

I bought a similar unfinished project that came with triple webers and a over bored .030" block with dished pistons.  I never fooled with that stuff though and ran the dual SUs carbs like you have pictured and the stock 2.4 motor.  Great running fun car that never gave me any trouble.  Your SUs in one picture is missing the vent bung on top of the float chamber lid.  It looks good to me as is.  I'd put some molly grease on the cam lobes and pour 10W-30 all over the rest, especially the timing chain, and turn the cam sprocket bolt with a 27mm socket by hand to make sure it's not binding.  Plugs out with some oil squirts in those 6 holes too.  Good luck.

Oh yeah, a great book to get that helped me go from outboard boat motors and dirt bike engines to the L series Nissan's  https://www.amazon.com/Rebuild-Your-Nissan-Datsun-Engine/dp/1931128030

[Elliott000]

Thanks for the reply, I actually just bought that book and the modifications one too.

 

Is there a way to spin up the oil pump with a drill, just to check flow and that it is oiling out of all the spots it's supposed to? Under distributor? Also which direction to turn

 

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[JSM]

As long as you coat everything with oil, have it well lubed up and turned over a few times by hand,  with the plugs out and use the starter.  I've even left the valve cover off to make sure it's coming out the top.

[siteunseen]

24 minutes ago, Elliott000 said:

Thanks for the reply, I actually just bought that book and the modifications one too.

 

Is there a way to spin up the oil pump with a drill, just to check flow and that it is oiling out of all the spots it's supposed to? Under distributor? Also which direction to turn

 

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yes you can but you'll have to remove the oil pump, take the spindle drive out then remove the distributor and come in with a steel rod flatenened like the spindle gear and spin it counter clockwise or reverse on your drill.  

I found the thread that explains it all. 

here's mine running half speed on a drill, be careful or it'll shoot out running on high.

 

Edited May 8, 2018 by siteunseen

[Zed Head]

14 hours ago, Elliott000 said:

P30 block, unkown as to 2.4 or 2.6, n42 head, unkown cam and valve train.

The original engine size should be stamped on the flat spot above the #6 cylinder, the back one, on the right side of the engine (passenger side in the States).  The cam looks like a stock cam, the base circle has not been reduced.  The tag from the rebuilder makes it look a like a .030 overbore, so 3 liters seems unlikely.  I'm going to guess that it's an L26 that's had an L28 head installed.  The L26 had dished pistons, as I understand it.  Using the N42 head is probably a simpler way to get bigger valves.

The gap between the lash pad and the cam lobe is sign of a loose anti-rattle spring (aka mouse trap spring), I think.  Not a huge deal.

[Elliott000]

Ok good intel, the stroker deal comes from the PO saying they used a 2.8 crank. Ive read a bit about it but not a lot of info.

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[Zed Head]

 

Edit - maybe call that machine shop and see if they have records.  The tag has a number.

The longer stroke crank started with the L26.  So, it could be an L24 stroked out to L26 size.  The rebuild tag could be an old one of course, but .030" is a common overbore size.

Here are the stock bores and strokes for the three engines.  And piston types, as I understand them.  

L24  83 x 73.7 flat tops

L26  83 x 79 dished

L28 86 x 79 dished

Edited May 8, 2018 by Zed Head

[Elliott000]

I tried to call the engine shop but they have been closed down for years

 

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[Zed Head]

I'm thinking that you have, basically, an L26 with a bigger than stock valves.

Here's an engine calculator to play around with.  Looks like about 8.3 CR,which is 280Z L28 range.  The head doesn't look shaved, the letters still have a lot of metal under them.

http://www.ozdat.com/ozdatonline/enginedesign/

I would check valve lash and the wipe pattern on the rocker arm pads.  People make mistakes, or sometimes just throw a bunch of parts together.  The N42 head's valves would hit the sides of an L24 bore, unless the bore has been relieved.  Might want to turn the engine carefully by hand to be sure there's no interference, before using the starter.

[Elliott000]

I got er on the stand and pulled the pan off. I can confirm it's an l24 I found that casting number. That in itself makes me want to pull the head and check for valve clearance as I've read an dbeen told from you guys there's possible co tact points. I lubed er up in n out top and bottom and turned it over, everything it smooth as butter. I did notice crank and rods are used but pistons are new and the motor is definitely un run. I have another head gasket, should I oull the head? Darcy is confident it's a 3.0 stroker but how can I confirm this?

Thanks in advance.

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