Hi, I am in the process of putting a rover 3.9 into my BGT and am trying to work out which route to take to fit an air filter that will provide enough air but is low enough to fit under the hood without a bulge....or at least a small bulge.
I have the standard 3" filter and am not sure if a 2" one will fit and if it does will the carbs get enough air.
K&N have a 2" an X-stream filter top. Will this fit and provide too much air.
Another option is use the Edelbrock 1002 foam filter.
I have sprayed all the car except for the hood and am desperate to start putting baby together and play. So any suggestions will be greatly recieved.
Many Thanks Ian
2" filter should be fine.
It's a case of trial & error. There are so many factors involved,The type of inlet manifold, the height of the engine, the type of aircleaner used. I have a Buick 215 inlet manifold, an Edelbrock 1404 carb., a low rider type cleaner & a 3" filter. BUT, I do have a low (1") hood scoop. Without the scoop I could only fit a 2" filter. Some of the aircleaners I tried ,the bottom plate fouled on the choke controls & some fouled on the choke plate with the top of the cleaner using a 2" filter. I fitted the scoop to get hood clearance when I fitted EFI a few years ago. For testing the clearance, I always use 3 lumps of plasticine stuck on the cleaner lid , one at the front & the others at the sides & close the hood very GENTLY.
Ian,
I've got the 1404 carb with Edelbrock Performer intake on my car seen here: http://www.britishv8.org/MG/SimonAustin.htm
Using a 1.5" drop-base filter assembly, 1 7/8" round K&N filter plus the Xtreme top. Don't worry about too much air. The 1404 needs rejetting to work with the 3.9 efficiently. Out of the box, it will run too rich.
I used the Clive Wheatley engine mounts so the engine sits higher than other mounts available. With this in mind, the Xtreme filter does protrude above the hood line.
Options around this: use a scoop like I have, an MGC hood, an RV8 hood or create your own hood bulge.
I am using a holly dual filter top but I cut of and welded one side closed. Future plans is to duct it out ofr the hole in the front valance with a round filter:
(http://www.rc-tech.net/cars2/mg2/cleanup/cleanupf1.jpg)
Here's my solution. The hose is silicone from an aircraft heater. There is a cold air inlet ducted from the front rad valance to the filter canister
DSC03583.JPG
There are a bunch of BOPR conversions using 2" filters. I assume they all use drop bases to some degree, but plenty of them out there. Just scan the "How it was done" articles... http://www.britishv8.org/Photos-MG-Conversions.htm.
I have a 2" K&N filter on a drop base.
Gives plenty of clearance, even with the louves dropping below the curve of the bonnet.
Enginebay7-1-11.jpg