Mario,
I'm still having trouble with this quad SU thing. I've never heard of it and it sounds like overkill. Seems like the intake pulses would give you a poor idle.
To tell what engine it is look on the passenger side of the engine, right underneath the last sparkplug. Should say "L-16" or "L-18" or whatever. If you can't make out the writing see the end
of this message for a more "visual" check.
Did you have a look at the car yet? Did he use a custom intake manifold? Does it have a balance tube?
I thought the Roadster used the R-15, R-16, and U-20. And the 311, 410, 411, and 520 got the J-13.
The L-20b (or larger) crank WILL NOT fit a L-16 or L-18 block. The journals are a different size. You CANNOT take a L16 out to 2300cc, 1900cc is probably the max for a "small block". Well
maybe you could if you ground down the journals of the crank and overbored the block to the max (the LZ-23's use a 89-90mm bore). But then your rod to stroke ratio would be crap.
A L-18 (or L-13 if you ever find one in the states) crank will fit a L-16 block giving you a L-17 (great MPG engine) unless you overbore the block.
A L-20b can use a NapsZ-20, 22, or 24 crank. LZ-22 "Frankenstein" motors, long rod LZ-23, or long rod L-20b w/ fully counterweighted cranks seem to be the "premiere" L-series powerplants (the
VG, SR, and KA motors are the current hot swaps). Check out this page to see all the possible combinations of L-series engines:
http://home.att.net/~jason510/Motorspecs.htm The L-16 and L-18 blocks have only one bolt above the water pump on the passenger side. These blocks are identical except the L-18 has a larger bore and ribs on the outside of the block.
The NapZ block will interchange w/ a L-series block. The only mod is a little bit of drilling to the oil jet. The L-20b, Naps-Z20 and Z22 have 3/4" taller blocks with TWO bolts above the
water pump. A Z-24 block (1.5" taller than a L-16) will have 3 bolts. Don't ever use a Z-24 block, they crack at the headbolt holes. You can even fit a L-series head to a KA or a KA 12V to a
L or NapsZ block.
Okay, I'm done,
Daniel