150rwkw from vh carby 5l??

[ajvx01]

Both me and a mate are keen to know what's involved in squeezing out about 150rwkw out of the old Aussie carby fed five oh..

Assuming its in good nick with a decent set of pipes what would people suggest?

Sorry for if this is a noob question but my mate is a jdm convert and until now I've been a v6 owner (don't assume p plater) so neither are terribly familiar with the Aussie 8 pre injection..

[DANNY8]

I'm throwin a 308 2gether at the moment for a mate, fairly confident it's gonna crack 150rwkw. Just a stock bottom end with new rings and bearings, fairly mild cam, yella terra heads, edelbrock manifold and will probably get a 750 on top. The same combo on another motor made 146rwkw with a smaller cam. Highly doubt you'll get close without head work.

Or, just go stock VN heads and you'll easilly get north of 150rwkw.

[Reaper]

Both me and a mate are keen to know what's involved in squeezing out about 150rwkw out of the old Aussie carby fed five oh..

Assuming its in good nick with a decent set of pipes what would people suggest?

Sorry for if this is a noob question but my mate is a jdm convert and until now I've been a v6 owner (don't assume p plater) so neither are terribly familiar with the Aussie 8 pre injection..

Compression, VN heads, TP dual plane manifold or similar, cam and tune the carb to suit the lot. Should get 150 RWKW easily.

Reaper

[ajvx01]

Thanks lads perfect feedback...

Two questions... Can we just bolt Vn heads on? Even though they are for injected? And why is it always Vn I hear not vs or vt series one??

And comp would just be shave the heads yea??

[DANNY8]

One of my other motors I built was a stock 308 with new rings and bearings, stock dish pistons, stock compression, stock VN heads, crane blueracer cam (biggest blue racer cam available for them, which wasn't huge), procrap manifold and a 750 vac sec and that made 174rwkw and was leaning out and had shit compression (I put std rings in it and turns out it was 40thou....whoops).

[DANNY8]

Thanks lads perfect feedback...

Two questions... Can we just bolt Vn heads on? Even though they are for injected? And why is it always Vn I hear not vs or vt series one??

And comp would just be shave the heads yea??

ya just hear them called VN heads coz that was the first motor they were on....any VN-VT 5L heads will do. Yeah they bolt straight up to a carby 308 block, just gotta change the cam to a VN-VT 5L cam, and change the intake and extractors to suit. Apparently the pushrods and rockers are different too.

To get the compression up u could shave the heads but that won't get it up to far. Best to change pistons and zero deck the block.

[showbags]

Fresh bottom end, VN heads, torque power hi rise manifold, holley 760 avenger & billet electronic dizzy has made 204rwkw. All in a sigma.

[Reaper]

Thanks lads perfect feedback...

Two questions... Can we just bolt Vn heads on? Even though they are for injected? And why is it always Vn I hear not vs or vt series one??

Yes they are a straight swap but you need to replace the camshaft and intake manifold as well. VN - VT are all more or less identical. There were some changes for special runs (VN 4 bolt motors for example).

And comp would just be shave the heads yea??

Plenty do but I'd do the job properly and fit hc pistons.

Reaper

[ajvx01]

You boys are champs all great info and the Vn to vt makes sense, I'd always wondered... Ok so cam needs to be changed for obvious reasons but why extractors?? They'd foul on the chasis if we used Vn onwards??
Also what intake manifold then as the vns are Efi...

Sorry for all the maybe obvious questions lads but only way I can learn!

[ajvx01]

Also what would be the most cost effective solution head wise? Cam is easy I got a guy who can set me up and I have a good Trans place I use..
So really after info on heads: Vn or port the vh's?? Which is the most cost effective? Only really after the 150-170kw rwkw region...

(also sorry if I keep changing tenses from "I" to "we" me and a mate both researching the same thing...)

[Reaper]

You boys are champs all great info and the Vn to vt makes sense, I'd always wondered... Ok so cam needs to be changed for obvious reasons but why extractors?? They'd foul on the chasis if we used Vn onwards??
Also what intake manifold then as the vns are Efi...

The exhaust/Intake port layout is different between the early/EFI heads. I forgot to mention the extractors before - they will need to change. A complete EFI top end swap is relatively easy on early Commodores however there are carb manifolds readily available to suit the VN style heads. Note how the middle two exhaust valves are side by side on the old style heads:



Compared to the VN style heads:


(Note: the above are not actually VN heads but aftermarket alternatives. The port layout is the same and that's the point of the pic).

Extractors to suit VN heads into early chassis are readily available from Pacemaker and other manufacturers.

Also what would be the most cost effective solution head wise? Cam is easy I got a guy who can set me up and I have a good Trans place I use..
So really after info on heads: Vn or port the vh's?? Which is the most cost effective? Only really after the 150-170kw rwkw region...

I personally would just transplant the whole top end of a VN - EFI and all. A stock set of VN heads (in good condition) will be as good as or better than a great set of ported early style heads. If you are sticking with the old school heads then look for a set of HDT B cast heads or similar and a Brock style intake. They are about as good as you will get for early style stuff.

Reaper

[ajvx01]

Thanks mate that does make sense now...
Appreciate the help a bunch..

So to convert to Vn u need, extractors, cam, intake manifold and heads??

All valves etc too I presume?

[Reaper]

Thanks mate that does make sense now...
Appreciate the help a bunch..

So to convert to Vn u need, extractors, cam, intake manifold and heads??

All valves etc too I presume?

Well if you buy a set of VN heads they usually will come with valves. If you are going to all that trouble get the heads done up - valve guides are nearly guaranteed to be stuffed as are the seats. VN valves (at least in size) go all the way back to the old L34 Torana days and had been used in performance Holden heads ever since. Pitty they didn't use the VN style head design from when they were developing the motor in the late 60's - would have made it an even better motor than it was for it's day.

Reaper

[ajvx01]

Fairo, can anyone reccomend a good mechanic in sa (adelaide) we can go have a more detailed chinwag and get to do the bits we daren't try??

[nasty1]

Clicks racing

[ajvx01]

cheers mate, why the refferance?
you've used them/ work there? heard etc?

[nasty1]

I know the guy.he used to be my father in laws aprentice years ago.

Specializes in all kinds of performance stuff.we had one of his hks in our wedding.


Youtube clicks racing

[ajvx01]

ah cheers mate will do...

[ari666]

you can get 150 at the treads from early heads. its just not all that easy and for all the money you will waste on headwork, you are still going to be capped at around the 170 mark.

i got 150 from mine. stupid cam, stupid stall converter, stupid diff gears and a huge waste of money.

go VN heads before you buy anything else!

[ajvx01]

cheers mate, exactly the info im after..

am i right in assuming some stock shaved efi heads will get me there? no ports needed?

[ajvx01]

thought.. is it worth just getting a 5L from a vs or so with low k's and bolting on a craby manifold?

Will this work?

is the bellhousing etc for box the same and what would be involved?

[DANNY8]

Nah don't worry bout porting them. Wouldn't even bother shaving them, just throw them on as is as long as they're off a good running motor. Mine was slapped together and not running the best and still got 174rwkw.

You could just use a whole EFI bottom end, but depends wat trans ur gonna use. I just sold an EFI motor to me cousin and we're doing that to it, just rebuilding it and chucking a carby manifold on it. He's using a t350 trans tho. If u wanted to stay trimatic, ya wouldn't be able to use an EFI block (turbo pattern) unless u got it redrilled or used an adapter plate.

[ajvx01]

cheers mate thats what im after..
just figure itd be cheaper to buy a good second hander than full rebuild?

no of anyone that makes adapter plates?
whatd ya sell the motor for (so i have ballpark idea)

[DANNY8]

If ur gonna run a trimatic it might be better just finding a trimatic pattern 308 and putting the VN heads on top. But if u don't wanna rebuild it make sure u hear it run, and check under the oil cap to make sure it doesn't have oil cooked over everything (if it's cheap enuf I wouldn't worry tho lol).

I sold the EFI motor to him for $450, minus the intake manifold, fuel rail, throttle body, the gear he doesn't need (no boltons either). Only catch with the motor tho was it needed to be rebuilt, it wasn't a runner. The previous owner tried rebuilding it and for some reason didn't turn over and I bought the whole car off him cheap....turns out he done the rods up waaaay to tight.

Adapter plates go for around $150 I rekon....but then ya MIGHT have to get the tailshaft cut down and linkages possibly modified as the gearbox will be moved back about 10mm, but not sure if it's enuf to put everything else out of whack or not.

[ajvx01]

thanks chief much appreciated..