"HEAD" question???

[Dirttrack510]

My apologies to Wayno, I didn't mean to mis-quote you. You said you had the Z valves and those are the 44mm ones. My machinist just said that the 46mm will probably work, just be real close to the wall of the chamber. Anyways, sorry again. :D You may still be correct, as he hasn't tried to fit the 46mm ones yet.

[wayno]

What does "notched" mean regarding valve seats?

 

 

What I mean by being notched is that they install the big intake seats into the head, then to install the big exhaust seats, when they make the hole for the exhaust seat, they actually grind/notch a little bit of the intake seat off with a tool they have, so the exhaust seat will fit, the seats actually over lap a little.

I just took another W53 head to the shop to have it done again, install 280Z valves with hardened seats(no brass), port the intakes to match the dual SU manifold, and check to make sure it has the L20b spec cam.

When I get it back, I will try to get photos of the overlap on the valve seats.

As you can see in this photo below, the valves are very close together, I will try to get a clear close up photo of the area when that head is done that I took in today.

I am still unsure about what I may be correct about dirttrack510, I just have the Z valves put in the heads, I don't know shit about it other than it can be done, I have others that know what they are doing take care of the specifics.

[EricJB]

Keep in mind, I dont have the greatest memory, but when I put Z valves in my head, I dont recall changing the exhaust seats. I think the Z exhaust valves are the same size as the L20. (1.38) Valve seats come in many different thicknesses. I'm wondering why they put oversize seats in your head. I know you run your work truck pretty hard, and the fact that they dont fall out say's they're doing it right. But if you ever need to replace a seat, you wont be able to.

 

Kinda like turning a crank -.040, when it only needed -.010 to clean up. Scratching my head.

[Dirttrack510]

It's not a "head" question, but it's related... Does anyone know the factory deck height from the top of the FLAT HEAD L16 pistons to the top of the deck? I've been looking on the internet and haven't found the info. I'm gonna be ordering my forged Wiseco pistons soon and I want a "0" deck height with flat top pistons. :D I don't wanna have to shave any material off the block to get it.

[Laecaon]

L16 pistons protrude from the block...

 

Check the Jason Grey info on the deck heights of assembled motors.

[Laecaon]

L16 ('68-'73 510 and later years 521pickup)

bore 83mm, stroke 73.7mm

(stroke/2)+connecting rod+ piston pin height = 207.95mm

piston deck height: 0.10mm (above block)

[Dirttrack510]

Thanks, I just found it... Thanks for the help. We're trying to get the highest compression we can outta this engine. Compression = Horsepower :devil:

[Laecaon]

Thanks, I just found it... Thanks for the help. We're trying to get the highest compression we can outta this engine. Compression = Horsepower :devil:

 

If you have a chance with your motor apart, could you measure your L16 rods? I have seen mention of 133.3mm rods, not 133.0mm. This was over on OZdat, so I am not sure. Doesnt make sense when you account for the piston height and the stroke, they would have to be 133.0 .

[Dirttrack510]

I haven't got all the parts handy, but I will when I can. :D I'm not going to use the factory rods though. I'm getting ready to order forged H beam rods. :P

[docbainey]

I haven't got all the parts handy, but I will when I can. :D I'm not going to use the factory rods though. I'm getting ready to order forged H beam rods. :P

 

Stock rods are actually quite good when prepped right.

 

I defer to the original HP book.

 

Are you putting in domed pistons?

[Dirttrack510]

I don't know for sure yet, it depends on how much clearance I have inside the head. More than likely I'll be running forged flat tops.

 

As far as the rods go, I realize the factory rods are pretty good, but in all honesty I can't bring myself to use them. I'm going to probably have $1200+ dollars in the head, $500 dollars in the pistons, a couple hundred in machine work on the block, plus bearing, etc... not to mention all the time involved in putting it together. With all that considered I just can't justify risking everything else to save a few hundred bucks on the rods.

[wayno]

Keep in mind, I dont have the greatest memory, but when I put Z valves in my head, I dont recall changing the exhaust seats. I think the Z exhaust valves are the same size as the L20. (1.38) Valve seats come in many different thicknesses. I'm wondering why they put oversize seats in your head. I know you run your work truck pretty hard, and the fact that they dont fall out say's they're doing it right. But if you ever need to replace a seat, you wont be able to.

 

Kinda like turning a crank -.040, when it only needed -.010 to clean up. Scratching my head.

 

Hey there Eric, fact is, I don't beleave these are not L20b heads, although I could be wrong.

I had one of these W53 heads rebuilt using the stock valves, I had the intakes ported to match the SU manifold, and I put a RV cam in it, my thinking was that even though I was using the stock valves, the cam would make up for not installing the bigger valves.

I realize now, that was defective thinking, as that fresh L20b engine, wasn't near the engine my wore out L20b was with the big valves and a stock cam.

The freaking engine has no torque starting out because of the RV cam, and it is terrible on the hiway, I am floored all the time just trying to do the speed limit, but you have to understand how I am using this truck, I rarely drive it without the fully loaded trailer connected.

I have sent another W53 head to the shop to have the big valves installed, I have before photos that will be posted in my LZ engine thread tonight, and when it is finished, I will post the finished photos there also.

[Jester]

Another guy on here is building a LZ24 that is getting valves that are just under 1.80" It is about as much valve as you can physically make fit. He is having the cambers reworked to make room for them. I'll make him post some pics on here when it gets back from the machine shop.

 

Stopped by the shop on my way home to check the head that came back this week.

 

Check out this beautiful head work. Those are 1.81" intake valves and 1.45 exhuast valves in a U67 head. Notice the material that was removed to make room. They machinist also rounded off all the sharp edges to remove any possible hot spots.

I think he said final came out to 46.5cc's.

 

 

He also had some port work done. Both short and long sides were "cleaned up".

 

[Dirttrack510]

WOW!!! 46.5mm is FREAKIN' HUGE!!! The work looks awesome too, and here I thought I'd have the biggest valves on RATSUN. :angry: I guess I'll have to settle for 2nd biggest!!! :hmm: I can't wait to hear how those work in the engine. It should really breath well. :thumbup:

[wayno]

Keep in mind, I dont have the greatest memory, but when I put Z valves in my head, I dont recall changing the exhaust seats. I think the Z exhaust valves are the same size as the L20. (1.38) Valve seats come in many different thicknesses. I'm wondering why they put oversize seats in your head. I know you run your work truck pretty hard, and the fact that they dont fall out say's they're doing it right. But if you ever need to replace a seat, you wont be able to.

 

Kinda like turning a crank -.040, when it only needed -.010 to clean up. Scratching my head.

 

 

I just read this post again, and I noticed something I didn't notice before, my head has been worked on 3 times now, the first time was when the big valves were installed in about 2000, the second time was a year later when It had to have all the seats replaced because brass was used the first time, and with the unleaded gas these days, the valves sunk right into the head, and the last time was just recently when I had it gone threw to ready it for the LZ23 I just built, and this last time they replaced all the valves because they were slightly to long/tall, and I was running out of valve ajustment after 10 years.

I am hard on engines I guess, but they always seem to get me home.

[wayno]

Now you guys have me wondering what I have for valve sizes, that U67 head is an open chamber head, so it is hard to judge the differance in the valves, but I took before photos this time, so I will be able to compare this time.

That head above looks sweet, it should breath well, what's the engine getting this head going to be used for?

[Jester]

Well.....the car was suppose to be just a fun run around, but, being he is an ex drag racer, he is building an LZ24. Cam will be around the high 460's or low 470's lift with a little higher duration than his current one in his L20. He hasn't decided on that number yet. Today he was talking about spreading ou the lobe centers a bit too.

 

A oic of his car.

 

[EricJB]

If you take a look at the lower head ( my junk) around the the valves and the lower pad by the spark plugs, you will see that the valves have been unshrouded. Material laid back around the valves. While this increases CC volume, it gives the charge someplace to go around the head of the valve.

 

IMO, the intake ports of a U67 dont need much more than straightening, smoothing, and match porting. The combustion chambers are in need of some work. I've seen a few heads on here with intake ports opened up HUGE, and nothing done to unshroud the valves. If it cant get in the chambers, it doesn't matter how big the ports are. I dont own a flow bench, or have any flowcharts, but I have done it to many different heads with good results.

 

 

Not to disrespect anyone elses work, just trying to share another way to increase flow. The heads are where the HP is

 

 

 

 

 

 

 

[EricJB]

I just read this post again, and I noticed something I didn't notice before, my head has been worked on 3 times now, the first time was when the big valves were installed in about 2000, the second time was a year later when It had to have all the seats replaced because brass was used the first time, and with the unleaded gas these days, the valves sunk right into the head, and the last time was just recently when I had it gone threw to ready it for the LZ23 I just built, and this last time they replaced all the valves because they were slightly to long/tall, and I was running out of valve ajustment after 10 years.

I am hard on engines I guess, but they always seem to get me home.

 

Wayno, your flatbed is definately a rolling testimony for how tough these motors are.

[wayno]

I didn't realize that I had these photos of the valve seats touching each other on my head, so here they are.

As you can see in the photo above, the intake is notched slightly, and the exhaust is left whole.

[Dirttrack510]

I just bought one of these to correct my timing issues for the shaved down head. I thought it was pretty cool and I won't have to figure out where to drill another hole in a stock sprocket. :D All I need to do is figure out my optimum timing adjustment. ;) Plus, once I have this sprocket I can use it as a template to mark my other sprockets. :thumbup:

 

[docbainey]

As far as the rods go, I realize the factory rods are pretty good, but in all honesty I can't bring myself to use them. I'm going to probably have $1200+ dollars in the head, $500 dollars in the pistons, a couple hundred in machine work on the block, plus bearing, etc... not to mention all the time involved in putting it together. With all that considered I just can't justify risking everything else to save a few hundred bucks on the rods.

 

Have you then considered Carrillo? Had a set made for our 2000, they where a 100 grams lighter then stock! Totaly indestructable. Cosworth also makes a killer rod. Either company will make what ever you want. Their pistons aren't to shabby either!

 

Here is a link to everything you wanted to know about con rods but where afraid to ask!

 

http://www.carrilloi...76/Default.aspx

[EricJB]

I just bought one of these to correct my timing issues for the shaved down head. I thought it was pretty cool and I won't have to figure out where to drill another hole in a stock sprocket. :D All I need to do is figure out my optimum timing adjustment. ;) Plus, once I have this sprocket I can use it as a template to mark my other sprockets. :thumbup:

 

 

I would still shim the cam towers, and use that to degree the cam. You dont want a slack chain slapping around in the cover.That is a nice piece. If you dont mind me asking, how much $$

[Sealik]

I would still shim the cam towers, and use that to degree the cam. You dont want a slack chain slapping around in the cover.That is a nice piece. If you dont mind me asking, how much $$

 

 

http://www.courtesyparts.com/nissan-motorsports-adjustable-cam-sprocket-s30-p-227555.html

[Dirttrack510]

What he said... lol... It was $92.00 plus shipping, I'm just hoping it's not back ordered and unavailable. :unsure: I already have the shims for the cam towers too. :D

 

As far as rods go, I'm considering the Pauter X-Beam rods, they're about $900.00. I'm also looking at the Carillo H Beam rods, around $1000. I haven't decided yet. Both are great quality parts. I'm gonna try to make this engine so it can really spin and not go... BANG!!!