Oddmanout84

If you search for slide hammers on ebay, theres a great custom made one that some guy makes that threads into the back of vice grips. Comes in several sizes, and is relatively cheap (like $30-$40). Screw the appropriate size bolt into the main cap, lock the vice grips onto it and slam it out. Unfortunately, I don't have one. I had to lever the cap out like the Datsun book says. I used a pickle fork and some pieces of wood to isolate it from the oil pan gasket surface while I levered the bearing cap out, constantly repositioning it to make sure it came out at the right angle. It was a pain.

Just a few of the top rings. All results were consistent. I was seeing if i could garnish any input based on the top rings first, because if I needed a new set because of excessive clearance checking the second rings and oil scrapers seemed like a moot point.

If someone ever crammed a 3 or 4 rotor setup into a Z... That would be pretty sick. Especially if it was a built NA. Although personally I don't think the sound fits a Z as well, it still screams like a banshee!

Well, I have a ring filer wheel, but it has the unfortunate inconvenience of only taking material away from the rings and doesn't add it! If my gaps were smaller than spec, I'd have no problem at all grinding them down. Unfortunately, they're a bit larger. I hope so. I'd like to imagine that it wouldn't make much of a difference either, but I'm trying to keep tolerances as tight as possible. Guess that's why I'm freaking out about it all. At worse I'll just end up with a lot of blowby and oil burning?

Any anecdotes on ring gaps used? Oil consumption issues?

So I'm rebuilding my shortblock and after all my clearances for the crankshaft have checked out well, I moved on to gapping my piston rings. I remeasured each bore (overbored the F54 block .50mm last summer) with a bore gauge and vernier micrometer with the garage temperature at about 50*F, and came out with a 3.409" bore. That's about 86.58mm, where the machinists bored to based on my 86.5mm ITM cast pistons and me telling them it was going to be turbocharged to 20psi max. There were no specs or instructions written on the box of pistons or the supplied rings. I have not been able to find much about the rings online, either. The boxes have no brand label on them whatsoever, but thankfully they do have a part number: SWN30066-2 CYL. Searching around discovered that this in an NPR part number, but still no specs. I looked up average gap specs both in my Datsun rebuild books and on the internet. The rebuild book says between .013" and .017", for stock engines. The "How to Modify your Datsun OHC" book says .004" gap per inch of bore, up to .002" more for high power engines. Online sources from Wiseco says .005" per inch (.0055" per inch second ring) for street modified turbo/nitrous. This site: http://www.aa1car.com/library/ring_end_gap.htm says .0045" to .005" per inch for a street performance engine. When I squared my first top ring into the bore, the smallest feeler gauge I could fit into the gap with a light drag was .020". Using the equation above, that's about .006" per inch of bore, which puts the gap into the recommended for "race only" category in just about all the sources I found. ****. I'm wondering, is this way too excessive? It sure seems like it, seeing as I intend to use the engine for a hot street car, not full blown race. All of the pistons are really just similar to OEM cast specs, except they've got Swaintech coatings. The most boost I plan on running is about 20psi (when I replace the stock turbo with a T3/TO4E). I'd have a hell of a time returning the rings, since the box set they came in with the pistons was purchased on ebay over a year ago. The only other option I guess would be to find another set of L28ET rings meant for a .50mm overbore, and even then are they going to fit my current pistons (if the ring manufacturer was say, Nismo or Perfect Circle)? Or am I really just flying off the handle and .020" is a good gap to go with?

Ebay. Should be a 4 bolt T3 flange with 2.5" ID.

Are you sure you want to bump the compression up that high? From my understanding (unless you're running very high octane race gas), using flat tops in addition to a 1mm head gasket and E88 head is going to result in an extremely high and likely unmanageable ratio. What's your current measured CR with the dished pistons?

How is that setup wrong? Its exactly as you describe it should be. The cold side is going directly to the throttle body.

Sounds like a vacuum leak to me.

Fix that rust first!

I hate to be a downer, but unless those coatings on the pistons are baked on, I can't help but comment on what a bad idea that looks like. In answer to your higher oil pressure question, there are spring and shim kits sold to adjust oil pressure. You should be able to get your hands on a DL Potter kit for a good price on ebay. http://cgi.ebay.com/ebaymotors/Oil-Pump-Relief-Valve-Spring-Kit-all-L-Series-Datsun-/160484571361?pt=Vintage_Car_Truck_Parts_Accessories&hash=item255da038e1#ht_500wt_900

There is a setup on Blackdragon auto that works really well. Just modify the mounting point on the bottle and you're set to go. Very easy, inexpensive, works excellent.

If you never try, you will never fail.

I will give this thread yet another bump for its useful information. When I got my turbo motor, the stock turbo on it was plumbed for water cooling, but there was little indication that the fittings were ever used. The line coming off of the coolant inlet was about 3" of hose mysteriously capped with a coarse thread bolt. Thermo housing only has two threaded holes left now with two NPT plugs blocking them. I had been curious as to if this was the proper way to plumb the turbo, and now I know. And knowledge is power. If I ever do that cylinder head cooling mod, that will mean I have used every single port on that thermo housing!

Because after power washing about 5 times the surfaces of my engine are finally clean enough to eat off of.

I didn't get much done today, but I did make progress. I've cleaned this block about 5 times now to make sure there's no contaminants or bits of metal and cloth. Clevite 77 main bearings are in. Plastigauged all the mains and everything is within specs. I hate removing and installing the main caps over and over again. The Datsun rebuild book I've been following says to wet everything with oil, but I figured I'd do it one step better. The Clevite engine assembly lube I'm using is the color and consistency of strawberry jam. Very thick, very sticky and gooey. It doesn't taste like strawberries though. Dropping the crank in was nearly a panic attack scenario. Rear main seal was smeared with molybdenum and put on the crank first. After laying the bead of RTV in the groves of the rear main, I had to rush to get the crank into the block and torque it down... along with several other things in between. Its also really hard to do seeing as I can barely squeeze fingers between the back of the block and engine stand. Though that assembly lube is great, its so thick that I could barely tell if the crank was moving back and forth when I aligned the thrust faces of the bearings. After everything was cinched down to final torque the crank spins freely... as freely as one can imagine something spinning in a jar of fruit preserves. Tomorrow if all goes well I'll be sizing the piston rings and installing the rest of the internal rotating assembly.

Yeah, I hear you. This is only enough for me to complete the block. I still want/need to get fuel lines, big front brake kit, LSD, and do a bunch of welding among other things. Progress is still slow...

Play him off, keyboard cat.

BRRRRAAAAAAAAAAAAAAAAAAAAAIIINS!! Seriously though, its not too hard, just time consuming. Label and disconnect your wire harness and other plumbing and test fit over and over to see if it fits and looks good. If it doesn't either deal with it and compromise for something a little less than ideal (but still functional and neat) or pony up and buy the needed parts to make it the way you want it. Just don't get so obsessed with hiding wires and lines that you forget to use proper isolation mounts and such, especially when it comes to SS braided lines and electrical wires. They tend to eat through each other when they touch for a long time, and the end result isn't pretty. In a helicopter, an insulated electrical wire will "eat" through an adjacent hardline carrying 1500-3000psi of normally non-flammable hydraulic fluid. The end result is a red mist aerosol that will most certainly turn into a gigantic fireball when exposed to a source of ignition (like electrical generators or the wire itself). Think about that when running fuel lines especially.

I smell the smelly smell of impending progress.... ... and a full set of new ARP hardware. The rod bolts and main studs had been held up in the midwest for quite some time.

Or you could go turbo KA24DE and have that torque and a smaller mid engine... But yeah, an L6 will always sound better.

A lot of people will say SR20 for the reason you just stated.