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What Carbs For Modified 1275 ?


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#1 Kevwana

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Posted 30 September 2016 - 11:24 AM

Hi, recently bought an 88 Rolling shell and have also sourced a 1275 mg metro engine to drop in. The engine has had some mods =>

1.5 roller rockers / Ported inlet / Polished chambers

Hi pressure oil pump / Piper 300 camshaft

Belt driven vernier timing gear..

 

Was wondering if anyone could suggest what carb setup would work well with this.. ? I haven't run the engine yet.. not really sure whether to go with twin 1.5 SU's / Single or twin weber 40's / weber 45

From my understanding the piper 300's are a high performance rally/race cam.. 

Any advice appreciated, cheers, Kev

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Edited by Kevwana, 30 September 2016 - 01:38 PM.


#2 Swift_General

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Posted 30 September 2016 - 11:50 AM

That cam is a pretty radical cam. What are you using the car for?

#3 Kevwana

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Posted 30 September 2016 - 12:22 PM

I did think that a piper 300 was slight overkill but this is what it came with so will see how it runs and go from there..

Was planning on building car as fast road/ track car so was planning on some engine mods but think a 285 would have sufficed.. any ideas how this will affect the running ? 

The BP300 cam is designed for high performance Rally / short circuit / oval race engines ,  where a wide torque band is required over out and out power . (Approx 300 ° duration)

 

That cam is a pretty radical cam. What are you using the car for?



#4 Dusky

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Posted 30 September 2016 - 12:58 PM

I Run a Split 45 weber with a similar cam.. circuit use only!

#5 Cooperman

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Posted 30 September 2016 - 04:36 PM

That is most definitely a race cam and it will need a SCCR gearbox and very low FDR. A 4.1:1 might work and the bottom end will need to be capable of around 7000+ rpm sustained.
It is not a suitable cam for road use.
A Weber 40DCOE should work well, or even a 45DCOE.

#6 Turbo Phil

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Posted 30 September 2016 - 06:09 PM

As above. Unless the rest of the engine is built to take sustained high rpm that cam will be pointless.
Do you know what's in the rest of the engine ? Rods, crank, flywheel ? You'll also need a very high compression ratio and a decent head to get the best from that cam.
Phil.

#7 Kevwana

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Posted 30 September 2016 - 09:29 PM

That is most definitely a race cam and it will need a SCCR gearbox and very low FDR. A 4.1:1 might work and the bottom end will need to be capable of around 7000+ rpm sustained.
It is not a suitable cam for road use.
A Weber 40DCOE should work well, or even a 45DCOE.

 

 

As above. Unless the rest of the engine is built to take sustained high rpm that cam will be pointless.
Do you know what's in the rest of the engine ? Rods, crank, flywheel ? You'll also need a very high compression ratio and a decent head to get the best from that cam.
Phil.

thanks for this guys, will running this cam have caused any damage to the engine ? am meant to be going to pick it up tomorrow so kinda need to know if this engine is likely to be goosed ! thanks..



#8 Dusky

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Posted 30 September 2016 - 09:39 PM

If its been used as it should it would have seen 7k tpm regularly...
Ofc, it could Be overcammed and never went over 3k.
Take a compression tester with you.

Edited by Dusky, 30 September 2016 - 09:39 PM.


#9 nicklouse

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Posted 30 September 2016 - 10:03 PM

But as you are not going to be using this build does it matter.

It ain't suitable for the road.

#10 gazza01

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Posted 01 October 2016 - 09:08 PM

Weber all the way. 






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