1800: Cool air for carbs

[sleek lemur]

Every little helps!

[Bracpan]

plus a clean engine...

[Ron Kwas]

sl;

If you have gone to the trouble and expense of the Webers, then it is clear you are looking for maximum performance, and that being the case, you should really provide cool induction air...you could make an airbox which breathes from through the original hole in front of Radiator...I've also seen racecars which breathed outside air from (the high pressure area in front of Windshield), but here is another solution on an earlier 1800 which did not have that hole next to Radiator...drawing induction air from wheelwell by means of a "rearfacing" Airbox (I believe made from the original 140 style Airbox, turned up-side-down) and flexcoupling!

Lutz Reeg of the Volvoniacs Forum pictures, used with his kind permission:



Volvoniacs Forum Thread: http://www.networksvolvoniacs.org/in...it:47,17/#last

Cheers

[Burdekin]

Agree Ron but some folk also like the intake noise they give without the air box.

[Ron Kwas]

B;

...and I am certainly among them...!...but when going for MAXIMUM performance with the Webers and all, I too would subjugate the desire to hear those wonderful sucking noises to letting them breathe cool, outside air...

Cheers

[Vintagewrench]

Letting the underhood heat and air pressure build up at speed out will go a long way towards eliminating this issue.

I road race a '67 1800s and to counteract air pressure buildup in the engine compartment (and resulting drag,) which was lifting the car an inch at speeds over 100 mph, raising the rear of the hood while latched 3/4"/19mm ended the problem (less of a rise would be necessary in a road-driven car.) The change also noticeably lowered the temperature in the passengers compartment while underway.

The resulting cooler under hood temperature caused the carbs to lean out enough so they needed to be adjusted to run richer which indicates the air temp under the hood was lower.

This can easily accomplished with rubber spacers under the latch brackets on the underside of the hood and longer machine screws. Longer flathead machine screws under the rubber bumpers that attach to the brackets on the cowl were used to raise the hood. It is quick and easy to do and completely reversible.

[Bracpan]

Originally Posted by Ron Kwas

sl;

If you have gone to the trouble and expense of the Webers, then it is clear you are looking for maximum performance, and that being the case, you should really provide cool induction air...you could make an airbox which breathes from through the original hole in front of Radiator...I've also seen racecars which breathed outside air from (the high pressure area in front of Windshield), but here is another solution on an earlier 1800 which did not have that hole next to Radiator...drawing induction air from wheelwell by means of a "rearfacing" Airbox (I believe made from the original 140 style Airbox, turned up-side-down) and flexcoupling!

Lutz Reeg of the Volvoniacs Forum pictures, used with his kind permission:



Volvoniacs Forum Thread: http://www.networksvolvoniacs.org/in...it:47,17/#last

Cheers

That is well thought out and looks good to, very nice.
I will make my own air-box once I've fitted twin SU's.. good idea to make it reversible..

[Vintagewrench]

Quote Ron Kwas:

"If you have gone to the trouble and expense of the Webers, then it is clear you are looking for maximum performance, and that being the case, you should really provide cool induction air...you could make an airbox which breathes from through the original hole in front of Radiator...I've also seen racecars which breathed outside air from (the high pressure area in front of Windshield), but here is another solution on an earlier 1800 which did not have that hole next to Radiator...drawing induction air from wheelwell by means of a "rearfacing" Airbox (I believe made from the original 140 style Airbox, turned up-side-down) and flexcoupling!"

Ron, Thanks for showing us Lutz Reeg's very nice job of engineering and constructing this system.

That being said, however, taking the outside air from the front of the car is a better solution. Air from that location adds the "ram effect" (small amount of pressure) and the air is much cleaner than that found on the inside of a fender well even on good roads. Yes, the air filter takes care of the road dirt, but on dry dusty unpaved roads like we have here in Vermont (US) it will clog an element fairly quickly.

1800 and Amazon racers for the most part duct air from either behind the grille, or from the back side of a modified right-hand headlight bucket with a screen fitted over the front.

[Ron Kwas]

VR;

I don't doubt or dispute any points you make, in-fact I totally agree...if I had to optimize breathing for Webers in an 1800 road (not racing) car, I'd probably route induction air from next to and in front of Rad, like the factory...apparently he already had his Cooling Sys Exp Bottle there...but he did a very nice job of it that I felt it was another option which could be shown.

As it is, and I "only" have SUs (not that I mind!)...and I like them to have the biggest Air Filter possible (K&N E-9145, lowest pressure drop for longest time as they fill with debris), Heat Shield (obviously!), and long VStacks, half for flow optimization (I realize they don't do much at typical RPMs!), half for the breast implant factor (they don't do much either, but improve looks noticeably!), but I'm still breathing "warmed air" from the engine compartment...

Cheers, from just down I-91!

[Heisser Asphalt]

Hello to all you forum guys,

my name is Lutz. I am German and this is my first post. And firstly I like to apologize for my English, which is suffering from a lack of practice within the last years. But I like to do my very best for you to understand what I'd like to tell. But maybe posting at this place will be a chance to improve, nevertheless my particular vocabulary in describing technical terms is quite poor.

Ron, thanks a lot for showing my intake air solution with the pics above. I really appreciate to take part in an international discussion about this and other interresting subjets, and I am pretty sure that learning from each other is the most important thing we are to do in nowadays' world ...

Regarding the comment of Vintagewrench about pulling dusty intake air from inside of the fender, I fully agree. But this can be avoided pretty easlily with mounted inner protection sheets (?). I use the Lokari parts at the front fenders, espacially for keeping the water off from all the corners and edges inside in order to prevent any corrosion. A proper side effect is getting a really large space at the top of the fender - which is completely dry, clean and ready to use as a huge air box with fresh and calm air. At the front end of the Lokari there is enough space for fresh air to stream in. But if not using any Lokaris I wouldn't suggest this solution at all.

All the best - Lutz