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Larger carbs? Crankcase breather w/ K&N's?

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cbrvfr

cbrvfr

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Hi, all

I have a 1957 BN4 Longbridge which was upgraded long ago by the previous owner to the 6-port manifold, and bored out to 3000cc.

I was under the impression that the SU's had been upgraded to the 1.75" bore ones, but as I was ordering a set of K&N air filters for daily use, I see now they're the smaller 1.5" bores. The car runs fine, but occasionally I see a set of the larger ones become available. Would it be worth my while from a performance standpoint to switch?

Also, what might I do with the crankcase breather hose, as the K&N's have no provision to route the blowby into the rear carb?

Finally, though I don't want to use the stock filters for daily use, I would like to keep them nice for the 'next guy'. They look as if they're painted. Anyone know what that code might be, in case the 'next guy' is a stickler? The car is pretty original in appearance other than the performance upgrades mentioned and a spin-on filter.

Thanks for your knowledgeable suggestions.
 
cbrvfr said:
Hi, all

I have a 1957 BN4 Longbridge which was upgraded long ago by the previous owner to the 6-port manifold, and bored out to 3000cc.

I was under the impression that the SU's had been upgraded to the 1.75" bore ones, but as I was ordering a set of K&N air filters for daily use, I see now they're the smaller 1.5" bores. The car runs fine, but occasionally I see a set of the larger ones become available. Would it be worth my while from a performance standpoint to switch?

Also, what might I do with the crankcase breather hose, as the K&N's have no provision to route the blowby into the rear carb?

Finally, though I don't want to use the stock filters for daily use, I would like to keep them nice for the 'next guy'. They look as if they're painted. Anyone know what that code might be, in case the 'next guy' is a stickler? The car is pretty original in appearance other than the performance upgrades mentioned and a spin-on filter.

Thanks for your knowledgeable suggestions.
Click to expand...
You maight check www.healey6.com website for air-cleaner article. I think it addresses the KN filter issue.
 
Side story: A few years ago I attempted a project with David Anton, owner of APT. I wanted to run K&Ns on my BJ8 with 2" HD8 carbs and, of course, fitting the front filter was an issue. I got a list of people that were interested, about 15-20, and David built a prototype filter set for me that I test-fitted. The results were positive but, unfortunately David's wife was involved in a serious car accident and his priorities were, understandably, diverted. We never finished the project but I'm still running the filters he provided (along with stubby ram stacks that are way cool).
 
Bob_Spidell said:
Side story: A few years ago I attempted a project with David Anton, owner of APT. I wanted to run K&Ns on my BJ8 with 2" HD8 carbs and, of course, fitting the front filter was an issue. I got a list of people that were interested, about 15-20, and David built a prototype filter set for me that I test-fitted. The results were positive but, unfortunately David's wife was involved in a serious car accident and his priorities were, understandably, diverted. We never finished the project but I'm still running the filters he provided (along with stubby ram stacks that are way cool).
Click to expand...
Got photos that you can post??
Thanks,
 
Aaarghh. I wish I had known about that, I test fitted them last night and it was clear that the front one was going to be a problem.

If the conical ones will fit without modification, These are going back to Moss.

In another omen of the impending apocalypse, I just ordered a windshield with all the rubber parts that seem to be giving others fits!
 
Patrick67BJ8 said:
Bob_Spidell said:
Side story: A few years ago I attempted a project with David Anton, owner of APT. I wanted to run K&Ns on my BJ8 with 2" HD8 carbs and, of course, fitting the front filter was an issue. I got a list of people that were interested, about 15-20, and David built a prototype filter set for me that I test-fitted. The results were positive but, unfortunately David's wife was involved in a serious car accident and his priorities were, understandably, diverted. We never finished the project but I'm still running the filters he provided (along with stubby ram stacks that are way cool).
Click to expand...
Got photos that you can post??
Thanks,
Click to expand...

Of the filters or stub stacks? The latter look like these (only larger, of course):

APT stub stack

The filters are just the usual 1.75" pancake style, but the holes for the front are cut as high as possible so the filter sits lower (just like a stock front filter). At that, it barely fits and clears the shroud. I believe you can get these filters with no holes cut, but it would be a trick to cut clean holes in exactly the right locations.

6906080518_a3674eb760_b.jpg
 
Joe Curto in Queens sells Jag spacers for the HD8s - they're about 1/8" thick, vs about 1/2" on the stock BJ8 ones. These are the black spacers between the manifold and the carbs.

This might add enough clearance for the stock 1.75: K&N to fit.

Also I see APT sells blank K&Ns - you could return one to Moss and use the other one as a pattern to cut the holes in the highest position per Bob Spidell's front carb above.
 
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