My engine drivetrain combo, looking for 10.5:1 or 11.0:1 compression.

[Jason240z]

Hi all.

I've used the search function;)

Bits below are what i've collected so are fixed(ish).

I'm 100% going to use the original block in my car(09/1970).

4.44 subaru plated LSD

Nisaan 200sx gearbox(C type) with shortshift

Mallory unilite with hyfire ignition-cdi

40mm webbers

Performance damper

Piper 286 cam, 290 duration, I can't remember the full specs off hand but can dig them out.

A set of 240z +1mm pistons

new rockers etc

I've got a 280zx engine in bits(f54 flat top/p90 head), exhaust will be a 6-2-1 with 1 5/8" primaries.

I want a slightly 'cammy' engine, thats why i've gone for the cam and 40mm carbs to work with it. 150-160bhp at the wheels would be nice.

What I can't work out is the best way to get to a higher compression ratio to make it all work. In the UK 95ron fuel is the norm, 97-98 ron in most garages.

I've a e31 head(that'll need hardened valve seats fitting for uk fuel), also depending on cost the option of a lightly worked over e88 head.

What will be the best way forward?

[madkaw]

Hello Jason

You are on the right track. I am running the l24 with early e88, basically a e31

9.55 ratio with SU's and made 155 running too rich.

I haven't had issues with detonation yet running 38 degrees full advance with 93 octane.

My cam is mild compared to yours and you will have 40's.

I just recently installed 40's , but not dynoed yet- definitely picked up some HP.

I'd recommend 280z valves and unshroud the chambers. Then work on the compression you want.

My head is shaved .016, but my block is heavily notched for the bigger valves and for better breathing.

I'd recommend you search Racer Brown and read is article on cams and Datsun motors.

I think you will be happy with the L 24 based on your HP goals.

[madkaw]

I will add that you should be looking for a quench distance- head to piston clearance- of .022-.025.

So you can shave the head to get your compression keeping the quench in mind.

Hopefully you have on hand the book- " How to hotrod your Datsun engine", lots of good info there.

[Jason240z]

Thanks steve

Seems like I am on the right track, I've got to get the block bored/honed and decked then measure where the piston sits at TDC. It seems like you've almost got the same spec engine, how does it feel? nice and revvy?

I've got 'tee books', I was more looking for people with the same spec and other useful info. The modern 5speed box and 4.44 rear end should make it quicker through the gears anyway.

[madkaw]

I'm running the subby 3.90 with the t-5 and I wouldnt want any lower than that for me. I'm running cast pistons so I can't be revving out too much - at least not like an engine with forged pistons and a big cam.

I do have a lightened flywheel that helps it rev up a bit quicker. Blipping the throttle is fun with the triples.

What I am always impressed with is the torque of this motor, and I only dynoed 155tq.

[Jason240z]

I've a lightend flywheel too, -5lb I think.

My gearing gives me a nice real world gear set, 60 in second(60profile tyre) and 135mph top end.