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

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.


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

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?

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?