Thread: Cracked Intake Manifold 3.5 81 Classic

That is a strange one, is it not leaking coolant ? There is a coolant jacket around the carb casting and into the manifold slightly so it should leak if cracked in that region. I cant see how there would be much stress on the manifold causing a crack, maybe just a casting flaw. I havent noticed an inner wall on any of the manifolds i have modified for a single carb.

Loanrangie; You have modified twin carb manifold to take a single 8O ????. HOW? do you mean taking off the old one and putting on a after market single one or do you mean you are actually cutting the old one somehow to fit a single. If the latter HOW???.

We would love to know as it would save$$$$$ on buying the over priced stuff Edellbrock sells .

Thanxs mate from Joe.

Only got back last night after 6 days away, you just cut the triangle casting off the manifold with a grinder and then get it milled flat, buy a 2brl holley to stromberg holden adapter and bolt it to the manifold after drilling and tapping holes to suit. You could also use a stromberg off a 253 if you arent keen on the holley, i have just swapped the holley and manifold from one rr to another with lpg setup and its great, good power and better economy.
Email me and i can email pics. I also have a 4brl holley to stromberg adapter and a 450 holley that i am going to fit.

Regards,
Nick.

Gave up on the cracked manifold theme.

Got myself an EFI inlet manifold, blocked every hole I could find, removed the throttle body, bolted in a supercharger and pressurised the system with some excellent results so far with a Holley 350 carb and 4psi boost.

Will carry out some durability tests and report back. All fabrication performed by my bro.

Wow - thats cool keep us updated!! 8)

Originally posted by Mangie
Gave up on the cracked manifold theme.

Got myself an EFI inlet manifold, blocked every hole I could find, removed the throttle body, bolted in a supercharger and pressurised the system with some excellent results so far with a Holley 350 carb and 4psi boost.

Will carry out some durability tests and report back. All fabrication performed by my bro.

So its setup as a draw thru system with carb before the blower ?

That's correct.

I have some pictures but I am not sure how to post them.

My RR had the setup with the alternator on the drivers side, I relocated this to the top where the air pump used to sit. The carb sits on the blower (blower donated from a toyota crown) and the forced induction is fed into the EFI manifold which now has an air fuel mix rather than air. The blower and carb are now located where the alternator once was.

So far it has been a pig to start but once it is up and running idiles quite well. As you can imagine I am running a little hotter than usual too, I am working on this along with a modified, or rather, custom made air hat and filter system. I only have 35mm between the top of the carb and the bonnet.

The blower also creates a vacuum sorce which now draws from the rocker covers. The particular blower is not very efficient and does not have any teflon seals or similar so the vacuum from the rocker covers also supplies some oily lubrication. This also stops blow by which can be produced by forced induction.

When I figure out the picture thing I will post them....

In general the low down power/torque is instant, 4psi is just amazing.[/img]