Building my 3.0 L soon - pics

[inline6]

Try going at it with a carbide bit first, and then following up with the sander. I'd imagine that the casting flash would cut through those belts rather quickly!

 

Where are you getting your rods from?

I had come to the same conclusion when I was designing an over the top turbo build for a customer who wanted to "keep it all datsun" under the hood.

 

Hmmm. Hadn't thought to use the carbide cutter... Thanks for that. A great example of when two heads are better than one. As for the rods, I am using Eagle brand for a Toyota Celica. My engine builder says they are ok, but not as 100% ready to go as others. That is probably why they tend to be more affordable. I forget the weight, but something like 560g vs. 710g stock - I think?

 

I will be taking the block to my engine builder after I finish removing the casting flash. I don't anticipate any issues with the block... I better not have any that is, because it would be wasted time and effort to remove the flash only to find out that I should find another block. He'll spec out the block, proceed with mocking up crank and rods to see what we need spec-wise for the pistons.

[inline6]

The crankshaft has arrived from Castillo's! Stroke came in a little less than I had hoped (3.165 instead of 3.188), but it was dictated by the factory stroke being a little under spec as well as tolerances when stress relieving the crank which happens during rod journal resizing.

 

As was mentioned before, it probably isn't worth the bucks spent for the small amount of stroke increase I have ended up with. However, those of you buying Rebello 3.0 liter stroker motors are pretty much doing the same thing.

 

Here are some large pics:

 

Edited May 10, 2011 by inline6

[280zfreak]

Holy **** dude! You're really going all out. What did that crank cost you? $3165? lol

[inline6]

Yeah, spensive. A little less than my first car cost me. Which is really insane...

 

Took my N42 block to be cleaned and sonic tested last week. Should get it back this week. Still looking for some Glyptal if anyone has some sitting on a shelf. Otherwise, I guess I'll have to buy some new and then what is leftover will sit on my shelf... probably until I'm dead.

Edited May 19, 2011 by inline6

[Kali]

Looks like the build is going well. Havent gotten mine started but i have 3.1L built just working with the MS and tunning for now. Hope you get it running soon. Here she is outside and in the car for the moment:

Edited May 22, 2011 by Kali

[inline6]

***********Edit: Moved the following post to a separate thread...

 

I dropped off most of the engine parts with my engine builder today. The block is an N42 from a 77 Z (had round port head). Quick measurements on the bore thickness in a couple of accessible areas make me think I won't be able to do the 89mm overbore. This is going to be a NA engine... but we measured .175" in one spot on the front cylinder (freeze plugs are removed). Back cylinder, where accessible was in the .2 something territory.

 

It will be sonic tested in the coming days. From some threads I found here, the guidance seems to be .125" thickness for cylinder walls. Anyone have thoughts on this? I hoped to go 89mm on the bore with this block. Now, I'm thinking 88.5 will be more likely.

 

Garrett

Edited May 29, 2011 by inline6

[duragg]

Delicious.

 

Which cam are you using? Looks like the base circles are min'd out at the shaft diameter.

Know the specs?

 

TJ

[inline6]

Which cam are you using? Looks like the base circles are min'd out at the shaft diameter.

Know the specs?

 

TJ

 

I got it from Kinetic Sunbelt in GA. It has a lot of duration.

 

Based on some info in the forums here, Sunbelt was one of the last who did any L series development with the cams. That lobe profile is assymetrical, and designed to work with valve springs that only have 190 lbs at .550" (max) lift. At installed height, spring pressure is only 56 lbs. Less spring pressure (if adequate) should translate to more power and less stress on the valve train. Max rev dictated by the springs is 7700 RPM.

 

Intake

Seat duration 320 degrees

.050" duration 290 degrees

Valve lift with zero lash .565"

Hot valve lash .015"

Net valve lift .550"

 

Exhaust

Seat duration 315 degrees

.050" duration 274.8 degrees

Valve lift with zero lash = .565"

Hot lash = .015"

Net valve lift =.550"

 

G

[inline6]

So, I have been held up with the decision of what to do about my head. It is a late style E88 and I didn't realize the lack of quench issues with it. I explored all kinds of options, popping a flat top piston up out of the deck, welding chambers, etc. After chewing on it for some time, I decided to mill the heck out of it. At this point, it has had .107" taken off of it. Here is a pic of one of the chambers. The .6mm Nismo gasket is laying on it.

 

 

Chamber size is 33.2 cc. So, the idea now is to order custom JE pistons that will work with this chamber. I'll be running zero deck. Based on some earlier mocking up and measuring of piston to valve clearance, my valve reliefs will need to be around .160" intake and .180" exhaust. Piston to deck clearance will be the Nismo gasket = .024".

 

I calculate that between valve reliefs and a dish in the pistons, I'll need to find 11.75 cc's to bring the compression ratio down to 11.0 to 1. I could also open up the chamber a bit on the spark plug side, but I'm thinking it would be good to have the flat area there for quench.

 

I am hoping to run this thing on 93 pump gas with 35-36 degrees advance. If I can't do that with the Mikuni set up, maybe the Tec GT fuel injection setup can make it happen.

[Xnke]

Definitely open the spark plug side up...unshroud your valves before you call that head done. You can make that into a nice medium-quench chamber pretty easy, with a piston that matches the shape well. Look at some of BRAAP's photos here to see where to make the cuts, and it'll really help with the amount of material that has to come out of the pistons.

[josh817]

Don't worry too much about milling the head down a lot. You spent the money for the adjustable Kameari idler gear and if I remember it can adjust up to 3-4mm of slack plus you can shim the cam towers a little too before you run out of valve adjustment/lash.

[inline6]

Don't worry too much about milling the head down a lot. You spent the money for the adjustable Kameari idler gear and if I remember it can adjust up to 3-4mm of slack plus you can shim the cam towers a little too before you run out of valve adjustment/lash.

 

Yes, you also have to use an adjustable cam gear and time the cam because although the Kameari unit takes up the slack, the distance between the cam and the crank gets shorter. And this alters the cam timing in relationship with the crank.

 

Xnke, I'm not sure where to do more unshrouding work. The Nismo gasket is 91mm wide at 3:00 and 9:00 if I recall correctly. As you can see, the gasket is right at the edge of the intake valve. There is a little room left on the exhaust, but my bores are only going to be 88mm... As it is, I'll need to eyebrow the block for flow reasons. Should I take the exhaust valve area out to the edge of the gasket like on the intake side? Or, are you talking about more unshrouding elsewhere in the chamber?

[Xnke]

Look at the angle of the valves...open the valve slowly and watch what edges it gets close to. You want to keep at least 1/8" of free area around the valve periphery during the valve travel, where you can. More is good, until you start loosing chamber volume that you want.

[inline6]

It's been a while and I have an update that is worth sharing. Some more chamber mods have been roughed in, and I have a chunk of aluminum that my engine builder has made to hopefully provide guidance to JE for the custom pistons. With my E88 head cut about 110 thousandths, and valve unshrouding done, the chambers look quite a bit different than stock. Milling the head this much was done to try to get some quench. Welding was not a viable option because I had done all of the valve and valve guide work already.

 

Looking at the pictures, you can see that cutting this much off of the head does in fact give it some quench, but nothing like some of the other L heads.

 

 

The chamber is at 33.2 cc at the moment. I am shooting for 11.0:1 compression and will be attempting to run 93 octane. It you've read the previous posts, you know I've got a big cam, which will help... and I'll eventually be running EFI. To get the compression down from where it would be with a flat top piston, I'll need a piston with about 12.75 cc's of dish. We still have to add valve reliefs, which should add some more cc volume. So, the finished pistons will likely have a shallower dish than this blank:

 

Edited September 4, 2011 by inline6

[NewZed]

Curious - you said you milled the head to get some "quench." But you're using dished pistons. To get a properly shaped "quench" wouldn't you be better off to mill a pocket that matches your cylinder head chamber, in a set of custom pistons? It looks like the way you're going, you'll just have an odd shaped combustion chamber, with no real "quench" or "squish" action (as I understand the meaning of quench) during the compression stroke.

[rsicard]

Inline6:

 

NewZed is correct about the squish situation. The piston should have the same squish pad as that of the cylinder head or greater. The cylinder head could have more squish pad area to enhance squish. Then have the dish portion of piston deep enough to accommodate the proper static compression ratio. Good close squish is essential to avoiding detonation. The more squish the better. Additionally, the piston crowns, cylinder head chambers, quench pads, exhaust port, exhaust intake valve chamber faces should be ceramic coated.

[inline6]

Inline6:

 

NewZed is correct about the squish situation. The piston should have the same squish pad as that of the cylinder head or greater. The cylinder head could have more squish pad area to enhance squish. Then have the dish portion of piston deep enough to accommodate the proper static compression ratio. Good close squish is essential to avoiding detonation. The more squish the better. Additionally, the piston crowns, cylinder head chambers, quench pads, exhaust port, exhaust intake valve chamber faces should be ceramic coated.

 

I think I am doing what you and NewZed describe with the piston and dish area... it's just that the "quench pad" is quite small. Note that the piston is marked as .600" - for the distance from edge of piston to end of flat area, and the rest is dished. That .600" matches the flat portion of the combustion chamber in that pic. Also note that the piston has a .250" flat shelf running all the way around the perimeter. The idea is to have this work with the flat area on the spark plug side of the chamber... as well as the flat edges that are near the "main" quench pad. The flat areas of the piston will be put right at TDC and I am using a .6 mm (.024") thick head gasket.

 

When the valve reliefs are cut, I'll see if there are any other options to improve the quench (maybe a slight raised area on the piston to match the slant of the combustion chamber until the valve reliefs are encountered).

 

Does this make sense?

[NewZed]

I see what you're doing now. I missed the .600" quench area on the piston that matches the same on the head (basically I missed the point of your description and the point about your custom pistons - my fault). Looks like two squish areas, a small and a medium, across the combustion chamber.

 

I would think that you would need a certain ratio of squish to un-squished to push enough of the unburned charge to get the full benefit. I hope you have enough squish there to get some solid effect.

 

Looks interesting, good luck. Hope I didn't get your thread off track.

[Tony D]

After I have the motor together, this TWM 45 setup is going on to replace the Mikuni's. I plan to use the Electromotive FI for ignition with both setups... get the Mikuni combo dyno'd and then switch over to see how much more I get from the FI.

 

There was a Japanese Magazine that just did this, but to make it even MORE 'apples to apples' they simply removed the ventruis and booster chokes from the Mikuinis, bolted on a TPS Adapter bracket for them available in Japan, and installed a fuel rail on the carburetted manifold.

 

I can dig up the results when I get back to the hotel, but their improvement was along the lines of what we experienced on the LSR Car going from DCOE 45's to TWM 45's and Emotive TEC2.

 

I'll post back on the 'street car' article the Japanese Mag did, but our difference was this:

 

45 DCOE Power Peak 7500 rpms, 267

TWM 45 Power Peak 8250 rpms, 307 (40HP Total) Difference at 7500: 25HP

 

Total power area under the curve and torque was better with EFI, and the car would IDLE AT 900RPMS! With the Webers it was rough at 1700... And on a 39F morning for the November meet...oh man that was not fun to start. But EFI? Turn the key, and fires up to 1700 fast idle, then steps back down to 900 idle.

 

I recommend highly you do a good optimization and also try to record track times with the different setups. ESPECIALLY midrange acceleration out of a curve. The EFI should make drivability a dream if you had a formerly 'squirrely' cam! It let us play with gear spreads in the box becuse there was so much more torque at the changepoints. Not to mention the ability to run higher rpms when needed. Gearing may need to be changed a hair lower to take advantage of the higher rpms available with the EFI.

 

This same cam combination has not floated yet. This is the same cam and head (and EFI System!) that we run to 9500+ on the 2 Liter engine!

[inline6]

This same cam combination has not floated yet. This is the same cam and head (and EFI System!) that we run to 9500+ on the 2 Liter engine!

 

Hi Tony,

 

When you say 'this is the same cam', do you mean it is identical to the cam and valve springs from Kinetic Sunbelt that I have?