SU Help

[dan_2k_uk]

I don't think you should have too many issues with the hybrid engine. The g13 has a higher lift and longer duration cam so what you lose in valve diameter is made up in opening time and distance.

We did the same thing to a friends SJ and it worked well on the SU.

[Rhinoman]

The g13 has a higher lift and longer duration cam

No it hasn't.

[twiss]

No it hasn't.

very constructive lol
any more information or just NO?

[ScottieJ]

I have read that the 1.3 carb and SPI cams have different profiles and different ratio rockers carb (1.3:1 and SPI 1.5:1)

Any truth in that?

Found these figures over on Pirate

1.3L Carb (1988 model)
215 Lift
166 deg Duration
36 deg Overlap
1.3L EFI (1990 model)
240 Lift
168 deg Duration
46 deg Overlap
1.6L EFI ('80s model, press in wrist pins)
255 Lift
175 deg Duration
74 deg Overlap

Note: Lift and duration measured at the cam and does NOT include the rocker arm ratio (1.6). Duration and overlap measured at .050 lift on the cam. Degrees are referenced to the crank.

One item I don't have is lobe center to 'degree' the cam. You'll have to guess on that one. If you run several numbers I'd be interested in what effects the cam degrees have (rpm power shift). I used a 1.3L EFI in my 1.6 motor, and degreed it 4 degrees retarded for added bottom end. How much of an RPM shift comes from 4 degrees I'm not sure of....

[Rhinoman]

Scott found it first :-) although that is a very odd way to measure a cam. As far as I know the rocker ratio difference is between the 1.3 and the 1.6. You can swap the rockers to get higher lift and more duration but at the risk of breaking them, I read that in an article about 10 years ago, no idea where, the guy fitted a performance cam and was snapping rockers so he fitted the 'softer ones'.

[ScottieJ]

I think I got rid of the 1.3 carb'd head i had otherwise I would compare the rockers with the spi head.

I've heard about a guy running the spi cam with the carb'd rockers with really good results, he said that it performed better than the Isky Cam he had.

[Rhinoman]

These are the numbers that I have from Superf1y on Teamswift, measured at the valve? with 0.5mm of lift.:

1.3 8V 330L/192D
1.6 8V 356L/202D

1.3 16V SOHC 308L/184D
1.6 16V In 308L/192D Ex308L/198D

[Rhinoman]

and degreed it 4 degrees retarded for added bottom end.

You advance a cam to get more bottom end power, does this guy really know what he is doing?

[ScottieJ]

good question

[Rhinoman]

Delving into the parts database there are at least seven camshafts listed and at least six different rockers, the rockers have the same part numbers as the G16A Vitara. If I randomly pull up the SJ413V-7 then it shows carb or fuel injection but only gives one number for the camshaft (with six supersessions!). The cams for the 1.3 and 1.6 have different numbers, the 1.6 shows different cams for carb v EFI
The SH410 Alto uses the same rocker arms as well.