If you are going down the road of replacing the velocity stacks I have seen good evidence that tapered full radius bell mouth stacks are the way to go...

Yep, your flows look close alright. I,ve had a similer prob in my car, what I did was fit a smaller engine mount, it dropped the engine about 10mm and the flows now clear.

all good ideas, appreciate it.

I thought of the elongating the bracket to block holes & dropping the whole motor down about 1/4" TO 3/8", that might provide enough clearance for everything including the velo stacks although I think the easiest solution to those are shorter ones, just not sure where to find them.

I also thought if I lowered the motor by that much I might be able to easily shim down the trans at the tunnel mounts by am equal amount with just washers as shims, that way everything will still be in alignment.

Benny - what are tapered full radius bell mouth stacks?

Tom - are you running 2 or 4 flat slides, congrats on the bike - should be fun.

so when people are talking about cutting mounts or fitting smaller ones what are you using, I'm not sure where one starts with that.

Evan, what I meant was that the A14/A15 mounts are higher than the 1200 mounts. They look close but are not close enough. They will work but... With just a flat plate it will sit higher... check out the wiki for photos and more details.

To lower the mount, I think you can redrill the holes in the bracket that mounts to the engine. This will fit the bracket higher on the engine.

What I did years ago was to cut the brackets in two and section out about 3/4 inch and have a welder put it back together.

Quote:

Tapered full radius bellmouths are similar but different to your velocity stacks. Yours are the semi radius, parallel type. The concept of the full radius is to improve the air speed entering the bellmouth [much like an aerofoil] and the tapered tube is yet another improvement in the ram effect of air entering the carb throat. Another point worth mentioning is that air typically enters the velocity stack in a doughnut shape, entering from the edge of the ram tubes rather than from the front, in the middle of the tube.

see pic for example.

OK Dave, I see what you were geting at now, its similar to the idea of elongating / ovaling the bracket holes to allow the engine to drop a bit.

After wondering what a bell mouth was google is my friend. Problem is finding a supplier, lots of info about them on other forums - there is a local weber guy in my area so I thought I'd check with him.

thanks for the pic.

Saw these on ebay

ebay

I used mazda rotary mounts, there a very simple mount with no offset....I fitted them by drilling out the locater hole in the bracket. It can be done with the engine still in the engine bay.

You best lower the engine till you get the sump about 12-15mm from the crossmember.
Do you know how much space you have there?
If you dont sort you mounting issues everything will be out and will cost more in
the end to make sure everything misses.
You might be able to keep everything.

At worst if you spend 120-150 USD you can do what Tommo and some others have done
and just get someone to fit the twin master cylinder under the dash.
You then will be able to fit whatever you like in the future if the single sidey
aint enough or to your liking, efi and who knows but its cheaper in the end for
future mods or fitments.

Datsss - which year & model mazda mounts did you use - RX7 ? That also seems like a good idea if I can just swap mounts.