MORE POWER..... No, im not clarkson, yet...

[carlo rossi]

Thanks 105 for putting on track
My understanding and I think what 105 is inferring is that the only difference that I know a group 1 head is that its been shaved so that you get a 9.7:1 compression to get the extra 30hp there are changes to the carbies cost around $200
the Reason they dont rev is 2 fold 
A)The cams are setup wrong and are poor
b) the jetting is wrong
sounds like your bottom end is fine check the compression above 175psi is fine
the cams should be set up 102 lc's standard they are between 110 and 114 inlet and 108 exhaust
set the cams at tdc on the pulley and send photo of the cam marks
in the mean time get some euro 10548 cams mild but they will rev only about $200 make sure you check the lift should be around 10.1mm your stock cam is 9.6mm
get back to us with photos

[GG105]

You're not likely to keep up with a late 70s on 911 no matter what you do, unless its being driven in 3rd gear or by a learner. For a start you are down one litre and give or take 120hp+, depending on the 911. Weight will be about the same as your GTV and it will handle at least as well.

Its a noble endeavour, some years ago I used to regularly race a Viper Green 911 part of the way to work in my stock GTV6. I simply couldn't stay with it.

By all means modify the Nord or install a twin spark, but you won't stay with a 911 driven moderately well. Better to just enjoy the Alfa, or get a Porsche

[105junior]

I very much doubt you'll get an extra 30 HP just by shaving the head and some carb changes

[carlo rossi]

well im quoting Jim K and the homologation tables for a group1 tune that I have posted and as well as personal experience
started at 74hp rear wheel to over 105hp rear wheel and that is tabled as well and I haven't shaved the head!
please read alfa homologation under general discussion
BUT
to get this I changed the cams and set the LC's as stated
the carb undergoes different chokes, emulsions,main jet,idle jet,and air corrector
jim quotes 128hp rear wheel with these mods in a 105
which is around 160hp flywheel
up from 130hp stock
I spoke to some of the top end tuners in this club and they tell me a transaxle model losses around 45 to 50hp
from the flywheel to the rear ,much more than the 105's at around 30hp
so even at 45hp loss plus my modest 105rhp  thats 150hp reliable happy days idling at 800rpm
after this it gets very costly ask RIGI

[V AR 164]

 

[carlo rossi]

does your group1 head come with cams ( send photo) numbers on the cams
and can you measure the head to see how much has much it has been shaved
i think you might have what you need it just needs adjustment

[will lesslie]

Hi Will, From your post I assume you mainly use the car in the road and would like to keep it that way. You mentioned you have a Group 1 head available, is this something that you'd like to use to keep costs down, is it serviceable as is or does it need full reconditioning? What makes you think the head you have actually is a group 1 head?
Seems everyone missed your real question of the bottom end of the engine.
Sounds like your engine is just tired and lacking full potential hence you're not revving as freely as you'd like.
I guess my question to you is what are you wanting? A full race engine or just a nice bump in power and drive-ability keeping it roadable yet fun?
Many pros and cons come with engine transplants from other variants including TS swaps.

Its a race car, will be forever.... No need to drive it on the road really... The Head is certified from an ex Alfa Delta Engineer as a full GR1.... But the engine could do with a freshen up.

[carlo rossi]

depends where and how you race it will dictate which motor your allowed
assuming its the current nord version
this group1 head does it have cams? if so what numbers
can you check the size of the valves ? within reason
and it will have 9.7-9.8 compression on stock pistons
great find! before you play bottom end check compression

[martym00se72]

Just a simple thing but have you checked your plugs? My 3.0 would refuse to rev past 5.6k, started looking at ignition, timing, cams , fueling etc and then I read something about plugs, had a light bulb moment as they were pretty old, changed them and it was like I had changed the engine. May be 30 bucks well spent...

[Paul Gulliver]

Would agree with Marty on that one. Also add a few extra bucks and change leads. distributor cap & rotor button for that new engine feel. As I posted earlier getting an old engine to perform anywhere near original specs assumes all consumables on and around the engine are up to speed. 

[LukeC]

Don't forget to check to see if the carburettors are actually opening right up....

I could tell a story or two about cars that have done the rounds of Alfa "Specialists" and still not revved as hard as they should. New plugs, leads etc etc etc.... Yet the mechanic had failed to check one of the most basic issues with older Alfas:

The linkages get out of adjustment/wear. The worst case I have seen is one where the car would only just get to 120 km/h flat to the boards, let alone overtake. It was only getting 1/3 throttle.

When the pedal is on the metal, the carb should just be shy of being on full open... no stress on the linkages.