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supercharged 308

Hi all

I have a 308 black motor i want to put a 6/71 blower on it what mods should i be doing to the motor to make this happen any information would help a ton cheers gub



i have been looking at doing the same thing... from what i have learnt n been told to put a super charger of that size on a mild v8 wont work to well... ill give u a small list of what i have been told i need to mod...

new cam - super charger spec
heads need reco to suit s/c
forged crank
H beam con rods
Forged flat top pistons low comp to suit s/c
carbys need to be rebuilt to suit s/c

in the end a FULL engine rebuild to suit the extra hp, every thing need to be strong enough to handle the power of the s/c when it kicks in! i even herd i need to rebuild my th3500 3 speed!!!!

after making many calls to usa bout prices n builds it just was not worth it in my opinion... u could spend 18k on a super charged 383 n get 700hp or u could spend 18k on a 383 naturally aspirated n get 1000hp

cheers for the information a lot of money but u cant beat the look

Careful gub as all bonnet protrusions engineered from January this year on are now illegal.
Even the scoop height is tiny now for rego.
Email me if you want the new regs

If you want this more for show, you don't have to go overboard with engine mods.

You need a well built low compression 308 using quality parts and a cam with increased lobe centre and exhaust duration to suit supercharging.

Keep the comp to around 8:1 or 8.5:1 and just run 6 psi or less with the right pulleys. This will give you looks, some grunt, and run easily on 98ulp.

You can find boost calculators for compression ratios on the net that will give you an idea of your full compression.

You will need to setup the dizzy curve to suit the cam or it may ping under high load. Another essental thing is a boost referenced carby, best to buy one like a Mighty Demond or Holley (at about $1000) or simalar.

Cheers Steve

just keep the boost down to 6 psi and have some fun

just be sensible with it, don't thrash it and it'll be ok

if you want to give it a hard time you'll bust something quickly, in that case you'll have to spend some $$$ on the doing the bottom end properly

I used to have a skiboat with a 308 (Red block)and 6/71, pretty much the only holden thing on it was a block, the rest was about 12-13k worth of goodies I cant be to sure about exactly what was in it as I didnt build it and it was 10 or so years ago, as said above you need good pistons bottom end and cam, head etc to suit. I would go see a race engine builder as these guys do this stuff all day everyday.

I only need two tools.
#1 is WD40 for things that dont move that should
#2 is 100mph tape for things that move that shouldn't

Have a look at a weiand 177 blower kit. thats what i'd do with my 308 if i was going to blow it.


The difference between genius and stupidity is that genius has its limits - Albert Einstein..


Thanks for the information everyone.

Try this.It can bolt on to a stock motor for under $3000.00.Just the air cleaner sticks out. http://gallery.oldho...

Big block HZ 1 tonner
WB van
HJ coupe

that small charger would work!, as the other fella said u can put a bigger chargers on like u want to but whats the point when its only going to run 6psi... a kit is around 5000k might as well jsut get ur engine rebuild would be cheaper n would get better hp

trust me i wanted the whole look n sound half way i changed my mind! unless ur going 1000+hp not worth it...

most of my quotes for a 350/383 to be build for super charger, this is turn key ready to go, WITHOUT the super charger, was 13-15k for a decent engine to handle a top of the range super charger

... i really do like the sound tho ha

What type is this

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