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About Atomic

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    Datsun B310 Turbo Coupe 1978 & Datsun B310 Coupe 1978
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    Music, photography and DIY
  • Occupation
    Mechanical Designer

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  1. I have seen that video few years back. I'm not sure tho if the A15 block would require siamese rings between cylinders 1-2 and 3-4 due to relatively thin wall, maybe single ones could be doable. Somebody just suggested that I should just run only with copper spray between the block and the head, but I shrugged that as a funny joke.
  2. Got some quotations from couple of engine machining shops. I'll ask for couple more details before I make a decision. The cylinderhead should come from the machine shop this week. I'm most likely going to trance the cylinder bank and order a waterjet cut copper headgasket. I just need to know some material specs before i send it. This is turning out to be quite expensive to boost A15 motor with the results I'm seeking for. Probably would have been cheaper to buy another engine with same hp on stock. But most likely that would have been bigger displacement one. Oh well, let's see how far this A15 will let me push it. And then I got some license plate lamps from the post:
  3. I took the cylinder head for quick check in our local shop. Meanwhile I went to the garage to weld in some temperature sensors: Also got a new phone, loving the wide angle camera. It captured the discoloration of the stainless steel really well. I should be able to control cylinder spesific fuel target after installing these and then the cam position sensor. The temperature sensors will mainly act as a +-2% correction for the individual cylinder based fuel map.
  4. I wonder if the bore size on Tomei gaskets of 79 mm is just for the gasket hole size, looks like almost close to stock one between the cylinder liners:
  5. Alright, I'll add that to the machine list next time. I should find some place where I can get the copper gaskets made to fit. I might leave the oil squirts out as it is making things a lot more complicated. But I can talk with the machine shop about that. I might end up running just E85 and that will keep the temperatures lower compared to gasoline only.
  6. I have a ceramic liner on the cylinder head and valves. I'm unsure about the piston coating now that they have been pre-heated and designed to take high heats. Aka my fear is that there is not enough heat to get a proper sealing anymore. I was going to put some oil squirts to cool the pistons but we'll see how it turns out, I must talk with the machine shops about that, there is very little space from the oil galleys to the cylinder walls as the crankshaft balancers are quite big. Not sure If I'm able to O-ring that block, the gaps between cylinders are small, maybe if using siamese rings. I was under impression that copper gaskets will almost always require combustion sealing via O-rings in boosted applications? I'm trying to find MLS or copper gasket manufacturers for custom order or stock option for A15 motor. All I can find is Tomei head gaskets for 79mm bore or smth
  7. Anyone knows a custom head gasket manufacturer?
  8. As for niddy-griddy stuff from the new pistons, * They have moved the first ring landing to 7 mm from previous 5 mm to move them away from the high temperatures. * On top landing they have contact reduction grooves which reduce the friction by minimizing piston material in contact with the cylinder wall above the top ring. They also serve as a way to disrupt pressure spikes caused by detonation which helps to resist ring unseating * The accumulator groove between the first- and the second ring to provide relief space for pressure that is escaping past the top ring before it attempts to pass the second ring. Therefore, it will support the top ring sealing by relieving pressure and it helps reducing ring flutter caused by pressure changes. * ArmorFit skirt coating is a self adjusting liner that will reduce noise and improve piston stability when it's moving up and down. http://blog.wiseco.com/piston-coatings http://blog.wiseco.com/ring-grooves
  9. Should be the same as before 8.9:1, or 8.5:1
  10. I have a plastic syringe in the garage actually. Everything was in inches, so that's why it was confusing what kind of unit it might be, but we will soon see I guess. The pin center hole goes to all the way to the top, so it's basically same as the stock piston as seen from the specs. They added valve pockets for some reason, even tho normal ones doesn't have them. Compression ratio will thus remain the same.
  11. Got these fast conversions and so far things are matching up: Huge improvement on top land thickness If anyone has an idea what might be the dome rise and dome volume units, would be nice to know. Datsun A15 turbo pistons Convert 25.4 Original Piston specs Forging F40097X Inch mm mm Comp Height 1.184 30.0736 30 Bore Size 3.0118 76.49972 76 Suggested Skirt Clearance 0.0035 0.0889 0.035 Pins Diameter 0.748 18.9992 19 Length 2.5 63.5 63 Width or Wire Dia 0.49 12.446 NaN Rings Top Land thickness 0.28 7.112 5 Top Grvoove width 0.0401 1.01854 Top Groove Root Dia 2.746 69.7484 Second Ring Land thickness 0.18 4.572 Second Ring Groove width 0.048 1.2192 Second Ring Groove Root Dia 2.7098 68.82892 Third Ring Land Thick 0.08 2.032 Third Ring Groove Width 0.048 1.2192 Third Ring Groove Root Dia 2.7158 68.98132 Dome and Valve Pockets Dome Rise -0.325 Dome Volume -20 Deck Thickness 0.525 Intake pocket Dia 1.6 40.64 37 Exhaust pocket Dia 1.325 33.655 30
  12. Got some goodies: I still have to confirm that all the dimensions are correct as ordered, so haven't had time to cross check yet
  13. I'll let the guys at the machine shop to handle them and check dimensions. What I just tested with new pistons and pins they work great together, nice snug fit.
  14. I will use the New forged rods that i have pictures on previous pages
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