KA24e in my 510, R1 carbs & MegaJolt. Ready for a bit more oomph - need suggestions

SON240sx Automotive
1

Long time reader, very rare poster.

I’ve got a '72 Datsun 510 with a D21 KA24e mated to a 240sx tranny (PITA to find a starter that works).

Here’s the engine details:

  • Yamaha R1 Mikuni carbs (rejetted) with 50mm velocity stacks, carbs are mounted on a Bogg Brother manifold.
  • Timing started with an electronic Datsun L series distributor retrofitted to the KA timing cover, but I moved to MegaJolt EDIS-4 crank fire for more power/control.
  • I rebuilt the engine with a .5mm overbore (89.5mm), with close to stock compression.
  • JWT S1 cam replaces the D21 cam.
  • Head is an eBay vendor rebuild with 3 angle valve, compression is 150-160psi.
  • Exhaust is OEM manifold to a 2" exhaust.
  • eBay lightweight flywheel
  • OEM crank pulley with trigger wheel welded on the back

The car drives great, sounds really nice at WOT, and overall is quite strong - my Speedhut Speedometer GPS 0-60 feature shows high 6 seconds (shift into 3rd doesn’t help). I really enjoy the car but am looking for just a bit more power - 25-30hp/TQ would be perfect.

Understanding that there are limited gains (KA24e after all), should I bother with any or all of the likely additions:

  • High comp pistons. I’m already running 91 Octane due to the bike carbs not liking Ethanol in the lower grades
  • Customer header - any recommendations in Ontario
  • Head Port & Polish - any recommendations in Ontario

Any other suggestions? With the tanking Cdn dollar I’m looking to limit ‘investment’ to $1000-1500.

http://www.son240sx.org/attachment.php?attachmentid=35573&stc=1http://www.son240sx.org/attachment.php?attachmentid=35570&stc=1

2

Maybe a JWT Stage 1 camshaft? Not a lot of cost, I noticed the extra power when I installed one in my KA24E

3

car looks great man! I think I sold you the transmission. Header and exhaust would definitely help you get a bit more power, ka’s love to breath you should go with at least 2.5" 3" wouldn’t hurt either. If you still don’t have enough out of it maybe nitrous?

4

Quite likely - did you accidentally throw in a Yankees toque? It’s kept me nice & warm the past couple of winters of the garage. :tup:

Thanks for the S1 cam suggestion, I’ve had one for awhile (listed in my specs above). While I never had a chance to compare before & after, the cam seems to offer good pull to close to redline.

This winter I’m going to install a 2.25" stainless mandrel exhaust which should help over the current 2" crush bent setup.

My next option is likely head work. Ideally I’d also love to shave the head a bit and gain some compression but am unsure if there’s any adjustable cam for the KA24e to bring the cam timing back into specs. Any suggestions?