Getting power out of an N/A KA - Page 3 - Zilvia.net Forums | Nissan 240SX (Silvia) and Z (Fairlady) Car Forum

PoorMans180SX · 11-08-2005, 07:02 AM

I was also interested in building my KA naturally, so I got some info on automotiveforums from NissanElitist here's what he said:

8500 is not going to happen reliably, neither is 8000 RPM.

The piston speed in a KA is too high to make it a high revving engine.

What you need to do is punch it out to a 90.5mm bore with a 11.5:1 piston with a Datsun fully counterweighted crank and an elongated rod. The pistons should be clayed for reliefs, and you more than likely want to drop the bottom oil control ring so you can move up the rod in the piston.

The stock DE head isn't that bad, run something around 235 degs. @ 0.050" duration with a moderated lift. Mild port and go to a 48mm ITB setup running a moderately long horn. Weld the chambers and rework their design, cloverleaf works well for swirl patterns. Keep the stock HG thickness to support the OEM quench.

You will need to modify the oil pump to supply consistant pressure at those RPMs, and check the water pump for cavitational flow (I would underdrive it about 15% anyways).

Large primary stepped header with a 3" burns collector.

Or you can save yourself alot of money, and build a RWD SR20VE engine and have 20 times the driveability for less cost.

I wouldn't recommend dropping the oil control ring unless your really serious though.

shinrekka · 11-08-2005, 08:13 AM

from what i've been reading up on, you cant go very high compression with aggressive cams on the ka24de, on the SOHC engine its another story. I've ordered quiet a few parts for my sohc.
Hotshot header, R4 cam, electric fan, light weight crank pully. I already have an injen intake and apexi n1 3" with a test pipe. Summer time hopefully i'll have enough money to get my head ported, new valve springs, dif valves and the engine rebuilt with custom high compression overbore pistons. Engine should be at around 11:1 compression ratio and 2.5litres. I am also going to get a custom intake manifold made up. I would think, i would be making around 200hp to the wheels. Im also currently looking into using the R5 cam, but i know of no one that has it or knows about it. Not many people have this much work done to a sohc KA, and the ones that do dont post here. There usualy in 510 or other non- 240 cars.

**Phlip** · 11-08-2005, 08:38 AM

1. this thread is a year old
2. this argument is even older, but 9 times more a pain in the ass

11-08-2005, 08:38 AM	#63
Phlip Yes, I look like that Join Date: Mar 2002 Location: In my supervillain's lair Posts: 27,980 Trader Rating: (19) Rides Gallery: Phlip Feedback Score: 19 reviews	1. this thread is a year old 2. this argument is even older, but 9 times more a pain in the ass __________________ Weirdo And I write too!

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11-08-2005, 07:02 AM	#61
PoorMans180SX Zilvia.net Advertiser Join Date: Nov 2005 Location: Michigan Age: 37 Posts: 5,616 Trader Rating: (16) Rides Gallery: PoorMans180SX Feedback Score: 16 reviews	I was also interested in building my KA naturally, so I got some info on automotiveforums from NissanElitist here's what he said: 8500 is not going to happen reliably, neither is 8000 RPM. The piston speed in a KA is too high to make it a high revving engine. What you need to do is punch it out to a 90.5mm bore with a 11.5:1 piston with a Datsun fully counterweighted crank and an elongated rod. The pistons should be clayed for reliefs, and you more than likely want to drop the bottom oil control ring so you can move up the rod in the piston. The stock DE head isn't that bad, run something around 235 degs. @ 0.050" duration with a moderated lift. Mild port and go to a 48mm ITB setup running a moderately long horn. Weld the chambers and rework their design, cloverleaf works well for swirl patterns. Keep the stock HG thickness to support the OEM quench. You will need to modify the oil pump to supply consistant pressure at those RPMs, and check the water pump for cavitational flow (I would underdrive it about 15% anyways). Large primary stepped header with a 3" burns collector. Or you can save yourself alot of money, and build a RWD SR20VE engine and have 20 times the driveability for less cost. I wouldn't recommend dropping the oil control ring unless your really serious though.

11-08-2005, 08:13 AM	#62
shinrekka Zilvia Member Join Date: Oct 2004 Location: Long Island Posts: 251 Trader Rating: (0) Feedback Score: 0 reviews	from what i've been reading up on, you cant go very high compression with aggressive cams on the ka24de, on the SOHC engine its another story. I've ordered quiet a few parts for my sohc. Hotshot header, R4 cam, electric fan, light weight crank pully. I already have an injen intake and apexi n1 3" with a test pipe. Summer time hopefully i'll have enough money to get my head ported, new valve springs, dif valves and the engine rebuilt with custom high compression overbore pistons. Engine should be at around 11:1 compression ratio and 2.5litres. I am also going to get a custom intake manifold made up. I would think, i would be making around 200hp to the wheels. Im also currently looking into using the R5 cam, but i know of no one that has it or knows about it. Not many people have this much work done to a sohc KA, and the ones that do dont post here. There usualy in 510 or other non- 240 cars.