3.5 carb V 3.5 EFI

[tvrmk363]

Morning gents,

What is the difference between the Carb'd version of the 3.5 and the EFI version if you only talk about the long block engine?
I know the EFI is better if running properly but I was wondering if the basic engine from the fuel system down is the same or might it have a different cam or other changes.

[Boosted LS1]

I suspect the efi could have slightly higher compression. Can you see the numbers stamped by the dipstick tube?

[tvrmk363]

Not near the engine at the moment but what does the number indicate? compression ratio?

[Boosted LS1]

Yes. Usually there will be an engine serial number and a compression number. Pre sd1 engines will be 10:1, sd1's 9.35:1 and vitesses etc 9.75:1. If 8:1 then it's low comp for the export market.

[The Hatter]

The heads changed at some point too, an older carb engine will not flow as well.

[adam quantrill]

The P6 engine was 10.5:1 and was supposed to run on 5*

Mmmmm num num tetraethyl lead.....

[Boosted LS1]

Yes, the early heads are are naff, very much so :-) allegedly.