L16 to L20b parts compatible?

[sondat]

Has anyone used ITM rocker arms? This is also an option via e-bay.

[Crashtd420]

Ordered new rockers from Nissan. Pre paid for 2 boxes of 5, but when they arrived the quantity of 2 units was only 2 rocker arms. (1 part box). The price Canadien was $64.93 per box so total paid was $129.86. Nissan parts looked into it with Nissan Canada and they are saying that 1 rocker arm is $64.93 even though when I ordered he stated I was receiving 2 boxes (10 pieces). Curious what your cost was Crashtd420.

Ya something seems wrong.... let me see what I can find in my notes....

[Crashtd420]

Well it looks like i paid around 30 us each .. so that would be 45 canadian... I got 8 rockers and the springs, plus a bag of dowels... $260... I don't remember but I believe I ordered from a nissan parts deal online.... they say 45 is retail, that would be 58 canadian. ...

If you went right to the dealer they might be a bit more... 65 canadian would be 50 us, so. . Not sure if that helps...

[Crashtd420]

And as far as Itm... if they only cost $10 How good can they be?.... my oem are still good .. if I didn't regrind my cam I would have reused them.....

If cost is an issue you could return the 2 you got and have your old ones reconditioned. But that can bring up other issue around the wipe pattern.. but that can be corrected with different lash pads.

[datzenmike]

Ordered new rockers from Nissan. Pre paid for 2 boxes of 5, but when they arrived the quantity of 2 units was only 2 rocker arms. (1 part box). The price Canadien was $64.93 per box so total paid was $129.86. Nissan parts looked into it with Nissan Canada and they are saying that 1 rocker arm is $64.93 even though when I ordered he stated I was receiving 2 boxes (10 pieces). Curious what your cost was Crashtd420.

 

I get $34 each suggested retail of which the dealer gets $20 of that for a 521 rocker arm. It's the same for all L series rockers. Take away the dealer mark up and that's about $15 each. This was 15 years ago but I doubt they went up that much. Go back and complain.

 

If you have the old ones and they are in fair shape you can lap them with wet 220 grit and a sheet of glass.

[sondat]

I was thinking of going back to that option of lapping them, out of the 2 sets of used rockers we have 6 don’t appear to have any visible wear or divot in the middle of the lash pad. So the next best 2 do have the mentioned wear. Unsure of the process on lapping, what’s the sheet of glass for? I get the 220 grit to dress them but not sure on the glass. What about keeping the 2 overpriced new rockers to use with the 6 decent used ones? Would there be to much of a variance in thickness between the new and old ones?

[Crashtd420]

I was thinking of going back to that option of lapping them, out of the 2 sets of used rockers we have 6 don’t appear to have any visible wear or divot in the middle of the lash pad. So the next best 2 do have the mentioned wear. Unsure of the process on lapping, what’s the sheet of glass for? I get the 220 grit to dress them but not sure on the glass. What about keeping the 2 overpriced new rockers to use with the 6 decent used ones? Would there be to much of a variance in thickness between the new and old ones?

I have no idea if that's a good idea or not. Trying to think how you would even measure them to compare...

I have about 16 old rockers and lash pads, i would have to pull them out and check condition but i don't see me ever needing .. I'll send you 2 good ones for the cost to ship... pm me if your interested...

 

And there are places that will reconditioned the rockers for you ....

I think they get around $10 to $15 us to do it...

[sondat]

Might be a good option, thanks for the offer. Don’t start digging for them till I know which route we will go.

[Crashtd420]

Might be a good option, thanks for the offer. Don’t start digging for them till I know which route we will go.

I know exactly where they are so let me know.... I actually have the full set from the head I am running now... I remember the cam looked really good before I sent it out for a performance regrind. ... I'll part with all 8 if it helps... Might be easier to start with a matched set..

Offers there if you need it.....

[sondat]

Thanks again Crashtd420. Just looked at the 2 sets we have, the set from the l16 has a substantial grove wore into pad that cam lobes contact. Second set from l20 head is much better. I am going to take those to local machine shop to get ther opinion and if they can re condition them. Will try and post pics later of the wear I’m talking about.

[datzenmike]

I was thinking of going back to that option of lapping them, out of the 2 sets of used rockers we have 6 don’t appear to have any visible wear or divot in the middle of the lash pad. So the next best 2 do have the mentioned wear. Unsure of the process on lapping, what’s the sheet of glass for? I get the 220 grit to dress them but not sure on the glass. What about keeping the 2 overpriced new rockers to use with the 6 decent used ones? Would there be to much of a variance in thickness between the new and old ones?

The glass is just for a smooth flat surface for the wet sandpaper. This will keep the rocker surface flat side to side and prevent a divot. Just use a rocking motion while dragging it across the paper.

 

 

 

 

 

 

[sondat]

I did get the original L20 rocker arms re surfaced at a local cam shaft machine shop so they should be good to go. I have also sourced a couple missing pieces to complete this engine build, the additional flywheel bolt which i posted under the 620 section and also an intermediate plate. 

So onto the next set of issues. As mentioned at the beginning of this thread my son and I bought this L20b apart, no reference pictures before disassembly. We do have his L16 which is older and some slight differences when it comes to cooling lines and emissions. 

 

Heres a picture of where we are at with the build

 

 

We have done some reading on ratsun about eliminating EGR system which we are doing. Also researched the routing of water lines, example is the water to the intake manifold. Still left with questions do to the mention of different configurations depending on what generation of L20b. I'm not sure what generation of L20 we have but here are some reference pictures with our questions following.

 

 

To start, I believe the vertical facing water outlet (on rad hose outlet above alternator) routes around the front of the engine and ties into the intake manifold? The tube on the left. we did read the question of there not being an exit for this water path from the intake. good question! FYI we will be adding the block off plate for the EGR system.

 

 

 

Next is the extra port from the thermostat housing (L shaped metal spigot). is it for turbo cooling? which we don't have. should i plug it off? Also what i believe is the water sensor for the EGR system (2 little black water or vacuum lines). We read that this can be plugged off if not going with EGR. The little double spigot piece could be used as a plug because it doesn't have any passage to the thermostat housing, right? 

 

 

Just to confirm, we believe the PCV valve is piped between the metal pipe out of the drivers side of the block and it goes to the longer metal tube from the intake manifold (pictured on the right side of it). 

 

This is a non EGR exhaust manifold not requiring any plugs, correct?

 

 

Thanks for any help with all these questions.

 

Here are some pics of 2, 620's slowly decaying into the earth. stumbled across these and have already offered up a couple of key missing pieces for our build.

 

 

 

 

Gotta like the old "sport truck" sticker, weren't those factory stickers?

Edited July 19, 2018 by sondat

[datzenmike]

This pipe mentioned in your text...

 

 

... and this pipe sticking up at an angle form the front base of the carb...

 

 

... should join at a metal Y pipe and travel down and over the front of the timing chain cover to this pipe...

 

 

This allows coolant to flow through the intake and warm it on cold days and cool it on very hot days. The intake air temp is more consistent and the engine runs more consistent regardless of the weather. The other pipe on the thermostat housing is the by-pass. The thermostat is not even on the engine and is surrounded by cold water even though the engine may be well warmed up, even close to over heating. Having coolant flow past the thermostat allows it to sample the true coolant temp and react by opening as soon as needed.

 

Look along the bottom of the head on the spark plug side just above the block it should say MADE IN JAPAN U67 With the U67? between the #1 and #2 plugs. It may also say W58 or A87. These are the most common stock head IDs.  If you have a U67 you will need to drill two 3/8" holes in it for the water cooled intake to work.

 

You can't run a PCV valve the way you have it now. The PCV valve would have been mounted on the EGR manifold that was attached to the left (driver's side) of the intake. What I did was grind away the intake and fill the bolt holes with JB weld. Drill and tap for the PCV and another for a vacuum port.

 

 

 

The holes that might have been in this exhaust manifold were for air injection. The air provided by a mechanical belt driven pump. An EGR manifold would simply have a fitting for a pipe to send exhaust to the EGR on the intake. I also switched to the L16/18 exhaust but just welded the air pipe hold closed.

 

 

 

Just now noticed it's a Sportruck. I think only sold in Canada with that decal. In thee States they were the L'il Hustler? So this is a '76 or '77??? Saw one in Sask. near the Alta border on the trans Canada.

[sondat]

Thanks mike, think I’m picking up on the waterline routing your talking about. There will still only be one passage of water into the intake manifold, no exit of water, is this the reason for drilling the intake if I had a U67 head? The stamp on the head is U60, will I need to do the drilling mentioned.

[datzenmike]

If you look on the intake you will see two holes, one each under the two runners. Look on the head and you should see the two matching holes. See picture.

 

 

I had a U67 head and simply used the intake/exhaust gasket to mark the locations on the head and drilled them out.

 

 

[Charlie69]

I personally do not run the coolant through my intake manifolds in the Pheonix AZ area.  I believe this is used to help warm the carb up in cold areas of the world.  Phoenix is not cold so it is not needed,

[datzenmike]

It doesn't warm the carb, so much as it warms the cold air and gas coming from it in the winter.  A warmed intake helps evaporate the gas before it gets to the combustion chamber. Gas itself won't burn until it evaporates. The more complete the evaporation, the sooner and more efficient the engine runs. Gas also absorbs heat as it evaporates.

 

Ahhh but it works equally well removing radiated heat from the hot exhaust manifolds just an inch away.  The intake is literally baked by the 400-600 F exhaust but with coolant flow through the runners, it is kept at or near engine temp. These two passages also help remove over hot coolant from the left side of the head around the intake ports.

 

So just like Goldilocks..... sometimes the air is too hot, sometimes it's too cold and then sometimes it's juuuuust right

[Charlie69]

^ LOL

 

I do not run married manifolds.  That is a NO NO in Phoenix for me.

Edited July 23, 2018 by Charlie69

[datzenmike]

What I find is the coolant ones just keep working while the co-joined ones have a heat riser valve that rusts in place. It's a thermostat that opens/closes a flap gate to regulate the exhaust that heats the intake. They can stick in any position unless cleaned or lubed and the external bi-metallic coil on my 710 was simply rusted away. They heat the intake but do nothing to cool them.

 

I modified a '79 L20B intake to look like an L16 and kept the PCV valve.

[sondat]

 

 

So comparing this manifold to your example Mike, I could drill the location for the PCV but the vacuum port you added I see there is already a hole on mine I could utilize instead of the block off plate where the EGR manifold was. What is the purpose of the tall tube off the right side of my manifold? Also any comments on the head we are using being a U60? herd of them? what would the differences be to a U67?

Edited July 23, 2018 by sondat

[datzenmike]

The tall tube is the vacuum source for the brake booster. The small one on the side of it, is for the modulator valve on an automatic transmission and blocked off on a standard.

 

I tapped a hole on an angle so the stock PCV hose would reach and filled the others with JB weld. The vacuum source was for the stock thermostatic air cleaner but you could easily run a line from the brake booster fitting.

 

The U60 appears to be identical to the U67 but I haven't seen one. If it is, you will need to place the new gasket over it and mark and drill these two small holes. I think 3/8" is large enough. 

[sondat]

Pictures havn’t shown but our intake already has the water jacket holes so good to go there. We went to dual reservoir but not power on the breaks so I guess we could cap tall tube off incase we ever upgrade to booster. Thanks for all the info Mike, so just the block off plate for EGR and drill/tap for PCV 

[datzenmike]

1 hour ago, sondat said:

so just the block off plate for EGR and drill/tap for PCV 

 

You can do that or just drill and tap the manifold for the PCV valve and any other holes just JB weld them closed. JB weld is a two part epoxy with metal reinforcement. Takes about a day to fully harden but can be filed a drilled, even taped for threads.

 

 

This intake is identical to yours with bolts and holes, I just got creative is all.

 

[sondat]

We have prepped the intake, took out the 2 long studs that the egr apparatus bolted to and cleaned out the 2 ports which were plugged with carbon. Think we are going to go with the block off plate (not JB weld). Want to make sure that the placement of the PCV and an additional vacuum port can line up with any of the 3 holes that the block off plate would cover. I see your example Mike then another option with block off plate. 

[sondat]

Heres our stab at the block off plate to do away with the EGR system.

 

 

 

 

 

 

 

 

Managed to source an intermediate plate and an extra fly wheel bolt since these were required going from the L16 to the L20b. This will allow us to mate the dogleg 5 speed and mount onto the frame tomorrow after work. 

Edited August 15, 2018 by sondat