madkaw

Here's some more pics of the project, mostly of the L-28 that supposedly only had 100k. The cylinders looked great as I said, but a good amount of rust on the crank around the flywheel end. A very strong groove in the seal area that I think might be an issue. The issue being that the amount of surface rust across the whole surface doesn't allow for moving the seal much to avoid the groove. I think I will be installing a speedy sleeve on there. Also interesting to me that the pistons all were labeled P79, I wasn't aware that Nissan did that. Am I assuming too much? Also asking(which makes me wonder if this engine was not touched) is the markings on the main bearings a normal numbering system? The machine shop said the block was straight across the top and I decided to reassemble the block with one piston to check deck height. Well it seems the rumors are true- about .019 above the deck. I guess I will be taking the block back to get shaved!!

Disconnect it and see if makes a difference

Megasquirt is already installed if that's what your referring to. Have another head coming from Florida of all places. Keeping my fingers crossed on this one.

Correct. You can do it yourself(drilling) and it's cheap and pretty much what all engines use now. Flywheel is very stable.

Cliff, I believe the bigger the jugs, the better( I leave that alone-) A bigger bore would allow for more unshrouding of the chambers which would lower CR to compensate for bigger bores. The unshrouding of the head would allow for better breathing!

First set back-head is so warped that it's junk. Good news is the junk yard refunded my money and I get to keep everything! So now I have a head to experiment and cut up on!!

Cliff, Better in the fact it's about a bolt on with no real modifications, Worst in the fact of the small chambers gives you less control of CR . The P79 allows you to choose your CR based on how much you shave. They both have a great modern combustion chamber. And as Jeff pointed out; there are other options than swapping out valves to make the p79 work, i.e. adjustable cam sprocket. The slight advantage of the Mn47 , from what I've read, is that the head was designed with small chambers and the ports have a smoother transition into those chambers. Where as the P79 with it's tall chambers has a tighter turn to make it into the combustion chamber. I'm going for broke with a high CR motor. I have 93 and 94 octane around here in Indiana. 1fastZ swears that with good fuel control and ignition this combo works well running full ignition. I do have an advantage running MS. Not sure if this motor will see Mikunis mounted on it or FI right away. I have a stock FI intake coming USPS.

How do you remove the shaft and still drive the oil pump?

Pic of your dizzy and the "small box" you described. Sure sounds like ignition .

You might want to read my megasquirt install thread on Hybridz. I think I also entered info here. I used the flywheel as my trigger and a 20$ Hall sensor. With the engine apart it's a good time to do this.

Those LS1 coils will weld steal! Great plan to use Megajolt. Looking like great project, should run strong.

So my engines apart and I'm wanting to check the carbs over before putting them back on. Since I was having running issues with my engine I really wanted to eliminate the Mikunis as the source. Everything checked out on the carbs, but I was suspicious of throttle plate damage from slamming the throttle(maybe a few times:o) Looking down the barrels with back lite I tried to eyeball the light making it through and see if the openings were the same. Checked for looseness in the throttle plates also. Some looked suspect, but still not sure how to measure the opening. Then I had an idea(careful now), what I checked the air balance with the carb off the engine. If I had a consistant suction I could use my unisync to measure any differences. So I dragged out the Oreck( my wife got excited for a second), and I hooked it up to each carb and measured. If this is an accurate test, then my carbs were pretty spot on. I plan on stteing all my idle screws using the vacuum. At least I will know they are all set equal. never did like using the feeler gauge

MN47-39cc p79-53cc 42 intake but 35mm exhaust Flow numbers are out there in the archives somewhere. Stuff I've read that it's plenty good to 8000rpm. The ports are Dshaped, but not sure how much smaller, but I don't think it's alot. I believe i measured 35mm across the inlet. Don't think there is any angle difference.

Putting a thread together now on this combo. We can discuss such options. As far as the head gasket; the L24 gaskets are oval shaped and should allow for room for notching.

I bought a f54/P79 zx motor about a year ago. Paid 200$ for a motor that came from a running car that had 110K miles-DEAL! I was just wanting a L28 block with flat tops so I could put my e88 head on when I was done messing with my L24. The bores looked great and it all cleaned up well. Had the block tanked and a ball hone on the cylinders. They magnafluxed the block and measured out the bores for me to check specs, all was good. 120$ At this time, I wasn't planning on using the P79, so I sold it off for 150$ Since my L24 project is going so badly, I thought I might try and work the L28 at the same time and use whatever engine is done first. But was headless. Always have been intrigued with the maxima head. It might be the best value out there for performance. They aren't as scarce as I thought and they are pretty cheap. It bolts on and has a more modern chamber like the P79, just a LOT smaller. I have read the archives and several builders swear by them. Maybe myth busting or adventure seeking, but a street gas 11:1 l28 would be a hoot. I have an advantage to the average guy that bolts it on and crosses his finge; I have MEGASQUIRT to fight detonation and lean spots and timing curves and.... I found an "A" rated head for 150$ shipped to my door. It was very clean and I bet I could have bolted it right on and it would have worked. But it is getting freshened up to get ready for a Rebello cam.

Here's my mn47 that's going on my L28

Zed, Not sure that Nissan would be the only ones that actually relieved bores on factory engines -at least from my research. You could be careful and notch the bore without dismantling the engine. Shaving cream and a drum sander would make quick work of it. A 2" drum sander with 80 grit and a couple of hours of prep and done.

That head is from a Datsun 810 or something? Bolt on, but you would need the exhaust manifold because its round port. Also need to relieve the bore for the larger exhaust valve to clear if you are at stock bore. In the end, you should have a better running motor than the stock. Should put you 10+ to 1 and detonation resistant. Getting ready to put that head on a L28.

Well blue just don't cut it in a red engine compartment. Black is kind of dumb, especially when you start trying to find oil leaks. Red off the shelf actually matched really well to my car, so there it is. The side seals; Guy, appreciate the tip, but the rear main is already bolted down and I don't own a puller, so it's a pain to pull back out. I've read numerous posts regarding these damn things and I have read no rtv, yes rtv, cap in place, cap not in place. I don't own the how to rebuild book, but i'm ordering it tonight! I have time to sort this out because my head is on B.O. I guess. Blue; I had SS valves in there before and I guess the machinist ordered SI valves to replace my old ones.

HUH?

Getting some stuff done, but need some verificaion. Ready to put rear main side seals and I need to be sure so this doesn't haunt me. See pics. "lips" to the block side, and stake to the crank side. I also noticed that the rubber seal has a slight taper to it. It definetly when in one way easier then the other. Not easy to see, but easy to feel. Still no head. The machinist found a flaw in the SI SS valves. Defect in the material. So looking for maybe a better 1.73 intakes.

I also was running 54 gears and a T5

My first long haul with my fresh L24 to Zcon 2010 I got over 30. SU's running very lean running max or 37 total advance. Amazing was that fuel gauge was dead nuts accurate using my CJ 5 gas tank - This was with a 480 lift cam and headers and electronic ign.

Those diesels are gone already

Curious that you are using he shorter rod-130mm?