Newbie L30ET Build

[EvilC]

69-72 vs 73 Connecting rods

 

When using the L28D crank, most people including myself thought you had to find 73 240z rods because they have the 9mm bolts vs the 69-72 240z rods are 8mm. If you are going to use STOCK bolts then you will want to use the 73 rods because of the 1mm difference of the bolt because it is "stronger" than the 72 and down bolts but they will work also if you have them. At the same time if you are building a 3.0 or 3.1 then using ARP bolts should be bought. These bolts are harden and are 9mm. If you have the 72 and down connecting rods, your machine shop can open the bolt holes to fit the ARP bolts. The bolt heads will need to be eyebrowed to make clearance for the bolt head to cylinder wall clearance. This is because the duration of the L28D crank is larger than the L28 crank therefor the clearance is smaller.

 

If any of the wording is incorrect, please let me know and I will edit it guys. I know some of you have way more engine assembly experience than I will ever have, so your input would be great!

[EvilC]

Boy time is flying!

 

Well wanted to update everyone what is going on with the build. I picked up the block and head yesterday from the machine shop....they look good! What did I get done so far?

 

Block:

 

Boil/Clean block

Magnaflux

Bore & Hone

Deck the block

 

Head:

 

Port match the head with the intake gasket

3 angle valve job

port n polish

shroud the head

new valve guides and new valves

installed Nissan Comp AL valve spring retainers

 

So I will try and get pics for you guys soon. My next step is to find a nice cam to match the work done to the head. I also will drop off the entire rotating assembly to the shop to get them balanced. I am moving slow but very excited!

 

Also I have to make an edit to the first post.....the red 71 Z car is now getting my V8 setup from the 73.

 

This car is getting the L30ET:

2/70 Z!

[z-ya]

Hi Clive,

 

Thanks for the update.

 

What are you doing with the 73'? Dedicated track car?

 

 

Pete

[EvilC]

Hi Clive,

 

Thanks for the update.

 

What are you doing with the 73'? Dedicated track car?

 

 

Pete

 

Pete,

 

No idea yet. I gave it to a friend but he has no where to store it and can't touch it for another 2 yrs!. I can't store it at the house cause my mother wants me to down size from the three. Between the v8 car and the turbo build....I can't keep it and make it a track only car. Any ideas? Maybe my new Z club track car?

[z-ya]

Any ideas? Maybe my new Z club track car?

 

That is what we did with a spare parts and a spare shell we had kicking around. After 7 years of upgrades, tuning, chassis work, it's damn good track car.

[nine2five]

hey man everything sounds pretty sweet! cant wait to read more good stuffs

[EvilC]

Well I had some time to snap some pics for you guys of my parts back from the machine shop. Please voice and concerns or thoughts that come to your head because I am trying to learn here. I took some nice size pics so you guys can see some of the work done. Next week I hope to take the other parts to the machine shop and get them balanced. Enjoy for now!

 

P90 Head:

Notice anything?

Gasket Matching of the ports:

Port n Polish...3 angle valve job:

Light Weight Nissan Comp Retainers:

Ready to be cleaned and painted:

Bore n Hone:

[Xnke]

Those chambers have not been unshrouded completely...look at the casting ridge around the intake valve seat. Everything i've been able to find on Hybrid, every L6 head porting post by 1FastZ, Braap, jmortenson, Johnc, all of them, says that that is one of the first things that needs to go. Maybe I'm wrong?

 

Chamber looks to have been beadblasted, but i don't see anything really unusual; care to let us in on what we are to notice? (I've been staring at pictures of P90 heads for three hours now trying to figure it out...)

[EvilC]

Xnke, exactly! I was reading through other post and saw that maybe I didn't get the chamber unshrouded enough..... maybe the experts can chime in here.

Here is some of the info I had read and pic I saved. Maybe I can finish up the next step myself based on Paul's pic I posted. Anyone know the % increase of flow that this step produces? I know it may be a silly question...don't yell at the newbie! lol

 

jmortensen-

You want to smooth the area from around the valve seat so that there isn't a ridge around the seat. This will allow the head to flow better at low lift. You want the max open area around the side of the valve where it comes closest to the headgasket. This is the unshrouding part. What you need to do is take the headgasket and lay it on the head, then use a scribe to mark where the headgasket sits on the head. Don't go past the line, because you don't want the top of the headgasket exposed. Then you grind away until the max amount of room is available around the side of the valve.

 

 

BRAAP-

And a P-90 that we just shipped out this week.

[EvilC]

For those who are noobs like myself and really wanting to understand what/why head work is needed...I hope this post can help out. I was able to contact a few guys I know who know their L motors and recap concerns and thoughts.

 

 

Here was my original picture that I had some concerns with:

…

Notice anything?

 

• That is a stock untouched chamber. It has only been bead blasted, No valve unshrouding was performed. You see the factory machine marks on the chamber wall beside the valve. Both intake and exhaust will have this. Some shops idea of valve unshrouding is using a dedicated cutter that just knocks back the chamber wall, which technically, is unshrouding, but only for the sake of calling it that, not for the sake of gaining air flow, which is why we unshroud the valves in the first place. A true performance port job that includes valve unshrouding, even if done with a machine, is still hand worked to some degree or another, regardless!
  

 

Intake Ports:

 

• The taper from the apex at the top of the injector slot is not consistent. Air flow wise it doesn't matter much but it may show the quality of the port work throughout. The inlets are not round or smooth. None of the bolt holes have been chamfered. They don’t really need to be, but it helps in keeping the aluminum that is adjacent the fastener from bulging out keeping the gasket from getting a nice flat seal between the head and manifold. On a decked block, chamfering the head bolt holes is mandatory, PERIOD!

 

Here is how the chamfer on the deck of the engine block should look, (sorry guys this was the only picture I was able to find on HBZ (head with chamfered holes));

 

Here are some pictures of a TRUE valve unshrouding. I was able to find this via search and thanks to Paul for letting me borrow these pics for my write up.

 

 

 

 

 

 

 

• Here are some pics of intake ports. Note how the entrance is round, not jagged. Also note the injector slots are consistent as they should be and not how mine are.

 

 

 

Another picture showing the port walls are smooth from the entrance to the seat.

 

 

So for a future head build here are some pointers to remember and think about. Also I would copy the pics here and make sure the machine shop can see what you are trying to describe to them.

 

If the step in the roof of the exhaust port was not reduced then all that work in the intake port was for nothing. Porting an L-6 square port head, in order of priority based on the air flow restrictions “through†the head, 1st is to unshroud the valves, a close 2nd is reduce the step in the roof of the exhaust port surrounding the exhaust valve guide.

 

This picture should help illustrate that. Note the hump where the valve guide resides is less pronounced in this picture vs a stock exhaust port.

 

 

 

So in the end my head needs a little more work and I hope to have it corrected. I hope this all made sense and a better understanding was made to why we port/polish the head and why unshrouding "the correct way" is important.

[Daeron]

awesome write up, good pictures for comparison, I hope that anybody whose pictures you used anonymously doesn't mind.

 

Really, having read these things many many times, I have to say plain and simple: the pictures tell the story. At least to those of us who are coming from Amateurville.

[S30TRBO]

Nice write-up Clive!

[EvilC]

Thanks guys, I just took the great info and posted it. My head will be going out again to be "fixed" will let you guys know how it goes and what was done.

[EvilC]

Ok, got my head back and will take some pics for you guys as soon as I can. Everything the first shop did was corrected or reworked. Thanks to the new shop that did the work, I have a better understanding of what kind of work goes into quality head work and why things are done. I am in th process of ordering a few parts for the block and hope to have it together within the next 2 weeks. Getting closer but still so far away. I plan to get the motor together and have it sitting inside the car by next month....fingers crossed.

[EvilC]

This is probably the most fun I have had with any Z car besides driving one!

 

Here is what we started with:

 

 

 

So to start off, two days ago.....painted the block with engine paint. Also installed new core plugs and clearance the connecting rod ARP bolts to the bottom of the cylinder walls. I used a grinding stone to do this about an inch wide. Be sure to clean the block and cylinder walls when done!

 

After some paint on the engine:

 

The next step was to install the bearings in the block and be sure to put oil on them. Then I rested the crank on the correct bearings, so I can install the main caps and check the clearances with plastic gauge (old school). The main caps were recommended to be installed to 40 lbs each. After I did that and checked the gaps, they were all good.

 

Next step was to install the connecting rods with pistons. BE SURE THE CAPS MATCH THE CONNECTING RODS. There are numbers on the side that you will see once you have them in your hand. Joe, showed me the method you want to use to install the rods and then torque down the caps. So I started off with cylinders 5 and 2. After installing both connecting rods to the crank....I go to turn the crank and....it does not move! Hmmm, Joe showed me that the oil sprayer needs to be on the passenger side of the block in the first rod we installed. So after 5 mins of looking at the motor, I check the rods and caps. Ha, now don't tell Joe but I think he turned the crank around while showing me how it is done and it was installed 180 degrees wrong direction . Now I did not help by installing #5 cap on # 2 and vice versa. I am myself here, so yes I made a mistake too So easy fix, take the piston and rod out...install it the right way and switch caps...and...torque it all back down. The crank turns!!!!!! So basically, I finished up the other 4 and I have no problems with clearance and the crank turns no problem. Lots of oil is needed as you oil the bearings, cylinder walls, and clean off the pistons before you shove them down the cylinders.

 

Me working on the block in Joe's garage:

 

Ready to install timing chain kit and finish up the block:

 

As it sits for now, this should be ready for the head next week:

 

 

Here is a pic of the head....doesn't look like much here but the sender was Braap. Paul cleaned up my head for me and did not do the intake port matching on my head...the original machine show did that. I will say Paul's work is very very very very very neat!!! Very good person to deal with and answers all my newbie annoying questions .....more pics to come:

 

 

 

So thanks to Joe for helping build this thing, I know I owe him a garage floor

[Rustyfriend]

BLUE??!?!?! NO NO NO....Lamborghini Yellow!

 

...just kidding Clive. But seriously, that is a sweet looking piece of machinery you got there!

[EvilC]

Thanks Adam...I hope to enjoy this turbo motor like you are with yours by Spring next year. Still waiting for the vids =P

[Rustyfriend]

I'll try to get some footage when I go drifting next week and head up to the drag strip as well!

[rags]

You, my friend, are good! Master mechanic! I hope one day to be able to keep up. Though that's not looking too good right now!

[rturbo 930]

Nice shirt.

 

 

Progress looks good!