Dattoman's Datsun 1000 Chronicles
Down to the business end of things with the power plant.
Basically we have a Datsun A14 block and head with A15 crank.
The following specifications are reasonably current however its a work in progress and has been stripped and re-assembled twice since this configuration began. I'm thinking of reducing the compression ratio again and fitting a larger camshaft as 12.9:1 is a little high for available fuel. However this means probably redoing valve springs ,rocker geometry ,valves, pistons, pushrods etc.
Nissan A Series Engine
Block: Stripped and acid bathed. Bored 40thou oversize ( 77mm )
Crankshaft tunnel bored for mains
Block face decked for straightness
Orig Nissan cleaned and polished
Conrods: Orig Nissan deburred/shotpeened/balanced/polished
Pin holes enlarged to take 20mm Mazda gudgeon pin
Rod bolt holes modified to accept ARP units ( poss Holden 6 or Chevy v8)
Mazda UC series 4 cyl units ( dished )
Top milled flat for deck height and comp ratio (12.9:1
Camshaft Engineering regrind cam Flat tappet mechanical
Clear hot Cam
inlet opens 40 deg before TDC closes 76 deg after BDC
exhaust opens 40 deg before BDC closes 76 deg after TDC
Datsun A series 1400 oval port
Datsun L series valves 38mm inlet 33mm exhaust ( inc lash caps )
Welltite inserts 3 angle seats
Ported , flow tested , chambers cc’d ( H.I.T.)
Holden 6 cylinder double valve springs ( crow cams )
Crow cams pushrods
Yella Terra Nissan A series shaft mount roller rockers 1.65:1 ratio
Mazda UC series std rings cast top ring
A Series std main , conrod and cam brgs
series gaskets ( head is A15 for valve clearance )
Carbs: Matched pair 40DCOE Webber side drafts
Modified throat sizes and jetting by Automotive Tuning Centre
A14 block bored .040 fitted with Mazda UC pistons with tops milled off.
ACL part # 2699. Crow pushrods just hanging out.
Block has been bored, cleaned (though it doesn't look like it) ,tunnel bored ,crack tested....blah blah.
Crow cams pushrods 6.650 inches long 0.080 wall thickness hardened moly.
You need to use this standard type pushrod with the YT Rolla rockers instead of the cup and ball type normally used on A series.
A14 cylinder head. No casting #'s on it so I don't know much about it. Note grinding between pushrod holes. I think this helps with oil return. I haven't blended the area around the exhaust valve. My flow tester said this wouldn't be required as the swirl is excellent.
Close-up of chambers. L16 cut down valves.38mm intake valves and 33mm exhaust. 24cc chamber volume. I need to mod gasket slightly so its not shrouding water galleries.
Assembled head with roller rockers and double valve springs.
Crap close-up of ports. They measure 30mm x 33mm exhaust (rectangle) and 28mm x 36mm intake (oval)
Yella terra roller rockers........yum.
1.65:1 ratio. Special order $590 in 1997 I was working for Repco at the time so I got them at very minimal markup. Kit comes with full shaft and pedestals. YT6024 is the part #.
Holden double valve springs with damper. Crow cams. You can just see the 8mm lash caps on top of the valves. After cutting the valve stems shorter to suit A series I didn't want them flattening out. Apparently this can happen due to the exposure of soft metal on the stem.
Mandrel bent headers in need of blast and jet-hot coating. These came with the car so I don't know much about them . I will be getting them cleaned and coated soon.
Top view of headers. I assume they are setup this way for maximum ground clearance. I have dunked them in acid and caustic and stripped them clean for ceramic coating since this pic.
These should help make some extra HP. Originally 40 DCOE rebuilt and throat size changed to 32mm if I remember right. EFI would be nice but out of the budget for this build......maybe next time when I dry sump the car and freshen the engine in a couple of years.
Flow chart for those who know what it means.
I don't understand it but it looks better than stock so hopefully we can extract some power and rpm out of this thing. Safely.Running gear Brakes and Suspension