What would happen if I put these on my engine (I have access to some)? I have 10548 cams and pace extractors, the rest pretty stock?
No good, I'll take off your hand!
they say 65mm is the optimum if you look at the original air box for a late model they have the runners inbuilt
get the original box
Sorry, my bad I actually mean carb mounts. Longerc solid carb mounts, rather than the rubber ones. What are the benefits and will they potentially work with current setup. Parts places say they improve midrange horsepower etc - is this true or only in 'everything tuned perfectly in sync' situations?
I read on various forums that the solid mounts are not recommended for everyday driving as the carbs don't like the vibration. Buggers up the float needles etc. requiring frequent maintenance.
Only what I've read though, no experience with them.
Quote from: Craig_m67 on April 22, 2015, 06:32:01 PM
I read on various forums that the solid mounts are not recommended for everyday driving as the carbs don't like the vibration. Buggers up the float needles etc. requiring frequent maintenance.
Only what I've read though, no experience with them.
Ok, cheers that's still info I'll consider.
Do they replace the rubber mounts or are they extensions? Ideally you want extensions, the mounting flanges line up with each other, and continue to use your original rubber mounts. Other wise you'll have to get the generic rubber mounts used for after market side draught applications. If they're extensions then happy days, you'll need to extend the carby support bar to but that's easy. At the lower mount that bolts inside the engine mount just use a longer bolt and sit it on top of the mount with some large washers that clamp on the mount when tightened. ;) ran a car like that for years.
You'll notice smoother running in the midrange and lower end. Not a massive power gain but certainly better.
Do an experiment and bolt them on, get dirty and enjoy your Alfa and what it stands for, tinkering on the weekends and understanding what things do ;)
If they replace the original mounts still try it. If you like it then invest in the aftermarket mounts.
Ok, cheers for that 105gta. I don't have them (in storage) but I think they replace the rubber ones. Will have to get my hands on them and have a look. I guess I was just looking into whether it could be done in isolation or whether more 'intensive' mods had to be done. Better does sound better tho.
for racing great more midrange
for road over time too much vibration
this came from a number of sites not personal experience
these came about due to the shortage of the late model siamese rubber mount
Can you get plain extensions to use with the rubber mounts? I've never found them before, but haven't looked for a long long time. Makes a lot of sense to me to try and keep the rubber mounts for a regularly driven road car.
I beleive it one or the other not both
go to dellorto Uk site
or eb spares Uk
You used to be able to get them, I've seen them in alloy, quite easy to make out of an old set of Alfa rubber mounts, just burn the rubber off and weld a tube between them at any length you like. On one end drill out the threaded stud holes I the existing studs for through. (8mm) on leave the studs in the other end. Done ;)
As for the Siamese mounts... if you run the original airbox, that links the carbs to be mounted parallel, so Siamese not needed. If using trumpets it individual it filters just make a small plate that bolts to both carbs so they are locked together. Also gives you something to bolt the original carby stay bar to. That takes the weight if the carbys and the mounts allow them to wiggle through the vibrations. The stay bar is the most important thing if all these mods. The original rubber mounts aren't designed to take the weight of the carbys.
Like this?
I have made aluminium casting ones for use with original carb mounts for 30 years now, still sell & carry them in stock.
Have sold quite a few in recent years to people replacing the solid mount billet types that give carb troubles.
Regards,
Vin Sharp
PACE Eng.
Funny, Vin, I was about to make mention of you having them!!!!! I was actually wondering when you will chime in.
Ok, thanks men. Will see what I've actually got when my father digs them out and I'm interested in the ones you mentioned Vin if that's a better way to go - will give you a call.
I have some of Vin's extensions behind the throttle bodies on the Giulietta if you ever want to take a look Damo.
Yep, sounds the goods Brent. Are you sprinting her at all this year? Otherwise I can take a stroll up the hill when you're free.
I'm going to do the next Morgan pk round and then the East Coast Challenge at Morgan Pk in the Sprint. I'll do the sprint round on July 19 and the following Italian Challenge round in Joolie. Working on the ALP Lord Mayoral campaign in Brisbane at the moment so driving 1000km/wk and lacking motivation when it comes to the weekends.
Cheers,
Brent
Brent, that sounds hectic. Will probs see you at the July 19 one.
Spoke to the old boy and what I've got is extensions that go between original mounts and carb. I understand this is the best option so I'm excited. They were fabricated by Randall Perkins in Syd in about '85 as far as we know. Cheers for all the input.
(http://i218.photobucket.com/albums/cc302/jamathi05/alfa%20advertised%203_zpsuovyyxv7.jpg) (http://s218.photobucket.com/user/jamathi05/media/alfa%20advertised%203_zpsuovyyxv7.jpg.html)
My car is a race car but I run the rubber mounts, (today replaced all 4 of them) with tube extensions between the rubber mounts and the 45 webbers. This optimises torque! one needs to look at the whole engine from intake to exhaust to get the best results.
Reviving an old thread because it asks some similar questions I have. In particular, what are the benifits of longer mounts? Are they generally a good thing for lower torque? Or particularly require matching to cam, port exhaust setup?
Ignore the vibration and acceleration of wear a little (which seems to be the be-all end-all of the threads I've read),I have a set of Jenvy ITB's, fuel injection conversion, to fit up and need new rubber mounts anyway. I have a few sets of "ok" used but now with ITB, I'm wondering if I just go solids. Long or short?
Directing this question to Vin might be a better option after I get the head off and see the valves and ports. Ex Race car, pace cams (10.5mm 320 by memory), 4-2-1 extractors, but no reliable info beyond that. It's probably not a clear cut answer without dyno comparisons and flow bench testing unless someone has been through it before.
I don't see a problem using the solid type mounts with EFI throttle bodies.
The reasons for not using solids with carbs is vibration of the needle & seat causing fuel level errors depending on the harshness
level at different rpms etc. & aerating of fuel in the carb bowl. Premature wear on the needle/seat tosses in another variable, so that cars that were once tuned & drove nicely deteriorate pretty quickly. Another issue is the 'O'-ring gaskets crush & leak air over time & need replacing often. Not a real issue on dedicated race cars perhaps. A LOT of people have retro-fitted Alfa rubber mounts after bad experience with the solid types, sometimes others seem to have no problem.
I can only assume the relatively tall, long stroke Alfa engine made in all aluminium amplifies issues, as other makes don't have such issues.
Having said that, over the years I have sold Alfa rubber mounts for use on other make engines because of similar carb problems.
& I still do 50mm long alloy spacers for use WITH the Alfa vibration & heat isolator rubber mounts.
Vin.