Hi guys, I have a 72 240 with a 2.9 stroker. F54 flat top block and N42 head. Dual Z Therapy SU's with SM needles, nismo motorsport 6-2-1 header, 2.5 inch exhaust all the way, port matched intake and exhaust.

its got a stock l28 cam in it however, and it falls on its face around 5500rpm, and has a nasty flat spot right around peak advance (3000rpm) that might have something to do with my static compression ratio from what I have read.

I have also read that with my compression (should be over somewhere just over 10:1) i should be running a cam with somewhere in the neighborhood of 270-290 duration on this build.

is this about right for this engine? and will i need better valve springs and lifters as well? or will the stock ones do the job?

Also, i'm not sure if I need an oil bar, I believe my n42 is from a newer engine, so I will need a cam that is right for my head i believe. or does it matter what type of cam you use?

I'm in the market for a cam as we speak, so if you have a combo that is suitable for the car, please let me know.

Call Isky: ISKY Racing Cams - Do It Right. Race with the Legend. Camshafts, Connecting Rods, Valve Springs, Lifters

I agree.....Isky is the way to go.....have them regrind your camshaft to Stage III. The Datsun metals are compatable with other parts in the L series engine. I would suggest that you install new or remanufactured rockers and make sure you understand geometrying a camshaft (centering wipe patterns) with the rockers. Also remember to run Isky valve springs to allow for the extra lift, which requires the shorter valve seals. H.P. is expensive eh? IMO

Edited September 2, 201410 yr by Diseazd

Looks like the Isky stage 2 or 3 cam is what i will want. coupled with springs and thicker lash pads.

While i'm doing this i plan on having the head ported out more. I'll also replace the valve guides and seals (she smokes a bit on decel) so i'll just have the shop install all the replacement parts since the stock stuff will be removed anyway.

Probably looking at about a grand for the job I'd imagine. but she should go like a raped ape after shes done.

I run a Web Racing #91 grind cam and my 260's 2.8L pulls strong to 7k. They too know what they are doing and have been making Z cams for decades. My cam is a new billet, but they also sell regrinds. Bryan Little talks about the Web Cam on his site.

Datsun Z Garage- ZCAR Performance Mods

Web Cam Inc. - Performance and Racing Camshafts

I'am also running a Web Cams #91 re grind on my 10:1 L28. Very happy with it, pulls hard to 7k no problem.

I've run a Schneider cam with good results

  AlexS13 said:

I'am also running a Web Cams #91 re grind on my 10:1 L28. Very happy with it, pulls hard to 7k no problem.

Alex, are you running L-Jet or carbs/aftermarket FI? I could not get my L28 L-Jet to run at all with a performance cam. I went back to the OE cam in that car and used the Web cam in my L28 SU car. It runs great with SU's.

Does their #91 grind require new springs and shorter valve stem seals?

Thanks!

I've heard, anything over .460 lift requires new springs to prevent stacking. Dave Rebello sells an outter spring that can be used with a stock inner spring that allows up to .500 lift. You can use the stock retainers with up to a .210 lash pad according to him. I like the Isky Valve Springs, but in the early heads, you need to use a shorter valve seal to prevent contact with the bottom of the retainer (not good).

Jeff, I'm running SU's on my L28.