Holden Sunbird power ups...

savage1987 · #1 25-01-2008, 10:09 PM

My girlfriend is looking into buying a 1978 Sunbird (4cyl Torana basically)...
I understand they make a dismal amount of power from the factory (60kw). What sort of power gains are there to be had from simple and cheap modifications??? Living in the hills a 60rwhp car really isn't ideal...

Any ideas let me know!!

Any info appreciated,
Cheers
Sam

Peanuts Inc. · #2 25-01-2008, 10:15 PM

lol.... well shave the head for higher compression... advance the timing about 4 degrees... run premium and thats about it

its basically a 6 cylinder with 2 cylinders chopped off the front

savage1987 · #3 25-01-2008, 10:22 PM

Just on that one.. how do you tell the difference between the Opel 1900 and the Starfire four?? The 1978 models came out with both... The Starfire four is the cut down 6 you're referring to... a motor with a bad reputation, apparently.

How much power do you get from the above mods?? Roughly, of course, not expecting a figure within 2hp lol; and how easy is it to shave the heads?

Sam

Sami · #4 25-01-2008, 10:35 PM

I've read about someone who's gotten their sunbird's engine ported and polished and had a "double throat webber carby"... that sounds impressive. Is it though? (I'm a bit of a novice here)

commsirac · #5 25-01-2008, 10:38 PM

The starfire motor will look exactly like a six cylinder red motor with two cylinders chopped off and is blue.......ive never seen the opel to describe it though. I believe that the code is L16 for the opel and L18 for the starfire, which is found on the vehicle's details plate on the left of the plenum chamber under the bonnet. On the motor itself the starfire will have a serial number starting with UN, whereas the opel will be UA.

I wouldnt be bothered spending any money trying to make it go faster, it will keep up with traffic and go up hills. It would be more sensible to actually buy a six cylinder then spend three to four hundred dollars minimum doing cylinder head mods to the four that probably wont achieve much anyway.
Buying a four and converting to a six, thats costly, youll need to buy a 2nd hand six and a different diff and have it all fitted.

These cars are going to feel slow regardless compared to the 145kW one has on tap on a typical v6.

Sami · #6 25-01-2008, 10:49 PM

I'm the one looking at the car btw

I would get the six, but to cut a long story short, I've been given $4000 to go towards a 4-cyl and a 4-cyl ONLY. Not my rules, obviously, but there you go. I'm entirely aware that it would be more sensible to get the 6 but thats not possible so we're just curious to know what IS possible with a 4.

Sounds sad but power is pretty important as it'll be a difficult transition from the newer commodores I'm used to, to a 60kw 4-cyl. I just want to bring it up to scratch.

Clutchy · #7 25-01-2008, 10:56 PM

Quote:

Originally Posted by Sami

I'm the one looking at the car btw

I would get the six, but to cut a long story short, I've been given $4000 to go towards a 4-cyl and a 4-cyl ONLY. Not my rules, obviously, but there you go. I'm entirely aware that it would be more sensible to get the 6 but thats not possible so we're just curious to know what IS possible with a 4.

Sounds sad but power is pretty important as it'll be a difficult transition from the newer commodores I'm used to, to a 60kw 4-cyl. I just want to bring it up to scratch.

Buy a barina or something like that over a sunbird unless ya can put a 6 in it as the four cylinder(missfire) dont have a good word to be said about them apart from the rods. why aint you allowed to get a 6 ?

savage1987 · #8 25-01-2008, 11:02 PM

LOL missfire... are they that bad!?

Sami · #9 25-01-2008, 11:04 PM

My mum (the one giving me the money) lives smack-bang in the centre of paris and therefore can't possibly see why anyone would need anything more than a 4-cyl, let alone a P-Plater. I can't really get a barina though... I've spent a lot of time paying out chicks in barinas so if i got one I really would have to hit myself. And laugh at my own car.

commsirac · #10 25-01-2008, 11:05 PM

Okay then, whatever the reasons. A mint sunbird would possibly cost $2-3000, and that'll leave you at least $1000 for the engine mods........still cant help you as I cant see the basics such as porting/polishing extractors getting you more than a couple of kW. They already have a very good (forgotten the name, its not a strombery) carby fitted(the starfire)(much better than the 6) and changing it would be unlikely to achieve anything either

Clutchy · #11 25-01-2008, 11:08 PM

Quote:

Originally Posted by commsirac

Okay then, whatever the reasons. A mint sunbird would possibly cost $2-3000, and that'll leave you at least $1000 for the engine mods........still cant help you as I cant see the basics such as porting/polishing extractors getting you more than a couple of kW. They already have a very good (forgotten the name, its not a strombery) carby fitted(the starfire)(much better than the 6) and changing it would be unlikely to achieve anything either

Ya mean the stromberg(spelling) mate ? they were on the 6 cylinder aswell mate hate to tell ya.

Clutchy · #12 25-01-2008, 11:10 PM

Quote:

Originally Posted by Sami

My mum (the one giving me the money) lives smack-bang in the centre of paris and therefore can't possibly see why anyone would need anything more than a 4-cyl, let alone a P-Plater. I can't really get a barina though... I've spent a lot of time paying out chicks in barinas so if i got one I really would have to hit myself. And laugh at my own car.

So will ya mum ever see the car ? just put a six in it its not hard to do just change the cross member to a 6 cylinder one not sure on the diff think they had the banjo in them and off ya go (I had a uc sunbird with a 179 in it and its the best car ive ever had)

Sami · #13 25-01-2008, 11:15 PM

omg what a hopeless cause. Looking at a mint sunbird for 2 grand so I've certainly got some room for improvement but if there's not much improvement to be had it won't be worth it. I don't like my alternative though... probably something riced and turbo-ed.

commsirac · #14 25-01-2008, 11:17 PM

Quote:

Originally Posted by Clutchy

Ya mean the stromberg(spelling) mate ? they were on the 6 cylinder aswell mate hate to tell ya.

Yes, stromberg(typo). Hate to tell ya, but you cant read. I said its not the Stromberg, which is what every basic six cylinder holden had up to that time. Its just come to me(the name), the starfire got the twin barrel rochester varajet, quite a sophisticated unit. Also afaik the cross member for the starfire is exactly the same as for the 6cyl, just the opel was different. They all had salisburys differentials, the 78's were the UCs, the sunbirds had 3.9 final drives whereas the sixes had either 2.78, 3.08 or 3.35