advice on fitting K&N's to SU's

A lesson learned. Although the bolt head on the back side needs to be ground back a little bit, don't grind it down so much that you strip the pozidrive slots out and end up twisting the thin bolt head off with a pair of vice grips. Man I was pissed, mostly at myself. I ended up welding the shaft to the back of the filter just to show it who was boss.











Just got the carbs back from Mr. Jimmy Hilton. I will have them on this weekend and am looking forward to it. Since I am almost broke (yeah, thanks MGB) I had to go with the budget rebuild, hence the carbs that don't necessarily look like jewelry. I went for straight performance. No frills.

I'm not sure I understand what you had to grind off. Mine just bolted right on with no mods.

I just test fit my carbs tonight to make sure I'm clearing the brake servo. Wow!! by about 1/4"!! I plan on getting her all buttoned up by end of day Saturday so I can drive her to the Queen's English Show in Van Nuys on Sunday. I'm just waiting for the tappet cover gaskets so I can mount up that pretty aluminum piece I got from Basil.

Good luck with yours Alex.

super sweet Alex!!!

Diyum,That reminds Me,I need to order two of those for Mine 78.:thumbsup:

Chuck, what I am talking about is the head of that bolt on the back side of the filters that fastens the shaft to the back plate. It is my understanding after reading some threads on this forum that the bolt head can vibrate / work it's way into your dash pot cover and scar it up. But, who knows, I certainly did not do the right thing.

As a side note on the radiator T / heater piping, I stopped by ACE Hardware and picked up a 1/2" and 5/8" hose barb with a 1/2" NPT threads and a 1/2" NPT 45 elbow and made myself a reducer that fit perfectly. It gives me just the right angle on piping up to that new heater pipe across the valve cover. I will post a pic tonight when I get home.

Chuck, you probably got a pretty thick cork gasket w/ the K&Ns to place between the K&N filter plate and the carb. This is to space the head of the through bolt or screw that holds the K&Ns together off of the carb air chamber/piston, referred to above as dash pot cover. This gasket may not be thick enough or may compress over time and the screw or bolt head will get pushed againt the carb chamber. Not good for a variety of reasons, including putting pressure on the chamber. One fix is to grind down the head of the screw or bolt that goes through the K&N filter plate which mounts to the carb.

In Alex's 4th pic down, you can see a little space between the K&N plate and the carb. The issue is whether that is enough space to keep the screw head that holds the K&Ns together off of the carb chamber cover. This is a tip from Jimmy Hilton. I had my carbs rebuilt by him, also. Wasn't sure what he was referring to until I looked at the carb chamber of my carbs and saw marks where the screw head from the K&Ns had marred the chamber cover in the prior installation.

Thanks for clearing that up. I just looked at mine and now I understand what you guys are talking about!! I'll be sure to grind that down a bit.

Cheers!!

Just a bit.

Had the same problem .
However your pictures failed to show the bolt head .
Poor engineering/design for an outfit that brags SO MUCH !

Hello from a relatively new member. I have a '75 Roadster, and the PO replaced the ZS with a single HIF-44. Runs good, but the trouble is: it did not come with an air cleaner assembly. The Victoria British catalog shows an HIF-44 (complete with air cleaner assembly) but does not offer the A/C assembly separately. Can you give me a part number or source of your complete K&N assembly?

Thanks, Gary

Another MOD ...On the rear filter assembly mounting i elongated the holes in the filter back plate
about 1/2 hole diameter which allows me to shift the filter assy foward for more clearence between
filter/booster.
Used gasket for template to make adapter plate from sheet metal to avoid leaks around holes and
glued the adapter in proper position with clear adhesive type rtv,,,invisible installed ..

RANT :: I dont think the ASS66les at K N ever looked at a late MGB or they
just sent a ojt kid to do a visual ,,,NOT a prototype installation !!!
Another sign of piss poor product development..

Of course another solution is to use the early style MGB (pre-75) filter cans. K&N makes a replacement filter for them.
Not as much bling but more filter area, and they can also be used with the aftermarket end plates (without the can) to
dress them up. They also allow you to use the radiused velocity stack/backplate of the earlier cars for improved airflow.
Note-These may interfere with the brake booster so check your dimensions before ordering.

When you install the carb setup, take the rear filter off.
The carb setup will swing right past the brake booster.
Tear your wrist up tightening the two center manifold bolts,
Replace filter.

NOTE... If your eng mounts are worn too much that rear filter can rub
on the boost can also..

Early filter cans won't clear the brakes. That's why the funky conical filters.

I thank the good graces that I got an early car.

[quote=Gary75]
Hello from a relatively new member. I have a '75 Roadster, and the PO replaced the ZS with a single HIF-44. Runs good, but the trouble is: it did not come with an air cleaner assembly. The Victoria British catalog shows an HIF-44 (complete with air cleaner assembly) but does not offer the A/C assembly separately. Can you give me a part number or source of your complete K&N assembly?

Thanks, Gary[/quote

Gary,

If you go to the MOSS website they sell the HIF-44 carb set up, but the filter is separate. It's on the same page as the carb.

Make sure you put some Blue loctite on the filter K&N top cover plate nuts. I lost one last year.

Personally, I'd lose the nifty acorn nut and split washer and use a flat washer and a nyloc nut. Not knowing how the innards are put together, I may also be tempted to use a rivet instead of the screw that seems to be troublesome, or epoxy.

This certainly seems like an appropriate conversion to whip up a decent air-box.

Bernard --What the hell is your problem with K & N ???? I have them on all 3 of my cars including my 76 coverted back to twin HS4s have had NO problem fitting on with the design !!!!!!!!!!!!!!!!!

Just to be consistent I ground the other bolt head off and welded the other side as well. I think it was a valuable experience for me at least, if I would have taken a little bit more time to really fit them up and see what type of clearances I was looking at I would not have not felt the need to grind off so darn much. I was just too excited to play with those new carbs...they sure feel smooth.

But, I need to keep my excitement in check since I have even more new toys to play with (got my dizzy back from Jeff today) and will attempt to get everything together for a first fire tomorrow. No need for stupid mistakes.

Here is what I did for the heater hose connection







Just some brass fittings from ACE and it got me the angle I wanted. Should work.

Thank You for posting up this information.
I am now ready to install the new air filters and have checked clearances and will need to grind tha screw head or else weld the shaft onto the filter back plate.
I have also installed new motormounts,both sides and also transmission,the clearance is going to be very tight to the booster but it will fit,I hope.:thumbsup:

Seems to me that shortening the spacers was what MOSS recommended with the kits they sold.