boxer conversion? any good?

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speedy s
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boxer conversion? any good?

Post by speedy s »

hi im looking into upgrading carbs from std su's,
can anyone give me any more info on the boxer 4 x 44 su conversions?
i dont seem to be able to find much info?
i.e power increase, mpg's and comparison against more common holley etc!
regards steven



chodjinn
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Post by chodjinn »

Think they were used on 4x4s mainly mate, there is one on ebay now

http://cgi.ebay.co.uk/ROVER-V8-BOXER-MA ... 286.c0.m14

ppyvabw
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Post by ppyvabw »

I've seen quite a few on ebay lately, and have been tempted. They look the business. Apparently they are quite good performance wise but not sure about mpg, bound to be better than webers mpg wise without the throttle pump I reckon.

Some people say they are a bastard to set up and keep set up properly, but I don't see how they can be much harder to run than say triple SUs on say a Jag.

speedy s
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Post by speedy s »

saw the ones on ebay, thats why i thought i'd post question,
i think they would look the dogs in my a30 pro street hot rod???
i my experience no amount of su's can be as hard to set up as my holley i had on v8 beetle, might of well of poured fuel straight from fuel can into carb!!
does that sound like a good price?
ar they fairly rare?

p.s thanks for replies!

mgbv8
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Post by mgbv8 »

Thats a good price for a funky manifold with 4 old MGB carbs fitted.
The HIF's can be fiddly to set up though.
They are a bit prone to suffering with engine bay temps in MGB's.

The Holley can be a pain to keep in tune by all accounts. I've gone for the Weber / Edelbrock 1404 50cfm 4 barrel setup on my RV8 which is easy to tune to your engine.

Perry Stephenson

MGB GT + Rover V8

9.62 @ 137.37mph

Now looking for 8 seconds with a SBC engine

http://www.youtube.com/watch?v=nVscbPHgue0&list=UUqIlXfSAoiZ--GyG4tfRrjw



https://www.youtube.com/watch?v=eg3avnsNKrc&index=2&list=FLqIlXfSAoiZ--GyG4tfRrjw

mgbv8
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Post by mgbv8 »

Sorry
I meant 500 cfm.

Perry Stephenson

MGB GT + Rover V8

9.62 @ 137.37mph

Now looking for 8 seconds with a SBC engine

http://www.youtube.com/watch?v=nVscbPHgue0&list=UUqIlXfSAoiZ--GyG4tfRrjw



https://www.youtube.com/watch?v=eg3avnsNKrc&index=2&list=FLqIlXfSAoiZ--GyG4tfRrjw

kiwicar
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Post by kiwicar »

Hi I ran this set up on a mild tuned 3.5 in my first range rover. They need a high compression engine (I ran 9.75 to 10:1) and will not work well with alot of overlap on the cam but apart from that a basic build is ok.
The manifold will run with prectically any 1.75" carb, SU or stromberg, I would go with the 1.75 su with the side mounted float chambers as these are easiest to work on. sort out a good play free linkage, if you are using two sets of SD1 set ups then renew everything you can on the linkage.
Initial set up is not difficult but you need to to pay atention to detail and be prepared to take your time. I rounded the front of the pistons on all 4 carbs as this reduces the turbulance dur to the pulsing of the engine and makes the mixture screws less sensative at idle you need to do all 4 the same though so make a gauge when you do it otherwise I left the venturies untouched.
First stage is the springs, carbs 1 to 3 need the recomended spring (which I think is two lighter than standard SD1), but fit the springs and check the lifting of the pistons over the rev range, again needles as recomended (I've forgotten the code but use what is recomended to start with).
When you set up initially work on all 4 but concentrate on carbs 1 to3 and get them working ballanced and working together, carb 4 has 2 pistons firing 90 deg appart and you set it up last, mine had a the same spring as the other three but I stretched it about 2" to preload it and then had to cut 3 coils off it and strelch it again so it would lift at the right rate, some fit the next spring stiffer, I had 10 40 in the dashpots on 1 to 3 and 90 weight gearbox oil in the dashpot of 4. as I said set up 1 to 3 then get carb 4 to work with them.
fuel economy ok about the same as standard SUs, needed a tweek about every 2k miles to keep them ballanced (with two sets of linkages they can wander really quickly) gave a big boost to mid and top end power over 2 SUs.
Mike
poppet valves rule!

ppyvabw
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Post by ppyvabw »

It's probably not beyond the bounds of impossibility to make your own similar manifold for not a lot of money and pick up four shitty old carbs and clean em up etc.... Ally if you can weld it or mild steel.

I considered this option too.

darren peart
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Post by darren peart »

I wouldnt go there you dont get much better than a holley and huffaker apart from this Image
Rover v8 powered manta 9.6 @ 141 mph

kiwicar
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Post by kiwicar »

Speedy Steven is planning on putting this in a 4X4, so unless it is just a Chelsea tractor he is best off with strombergs, SUs or EFI (or a bike carb conversion). 4 barrel carbs hate anything over 10deg off horizontal thats why you get 5, 10 and 15 deg angle plates for setting them up in your engine bay and kits to restrict sloshing in the float chambers under acceleration (or double float chamber versions).
I would love to see someone parrallel park anything with that tunnel ram on it :lol: :lol: :twisted: nice piece of kit.
Mike
poppet valves rule!

Riley RMF
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Post by Riley RMF »

Anybody reading this thread might be interested in my Boxer blog page on this site at

http://www.v8forum.co.uk/forum/viewtopi ... sc&start=0

Cheers

Phill

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