Author Topic: Advice on engine set up  (Read 4125 times)

keirv6

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Advice on engine set up
« on: 20:23, Wed 02 January 2013 »
Just rebuilt my r11 turbo engine and need some advice on the best carb set up ignition timing and boost pressure.
My engine spec
Balanced bottom end lightend flywheel
New pistons and liners piper 285 cam plus vernier
Head ported and mached to inlet alloy inter cooler
Turbo (not realy sure) defo a t2 but has no markings bleed valve fitted

Things I would like advice on
Best boost pressure
Carb jets to suit boost pressure
Ingnition timing to suit above
I have set ignition timing to 9degrees by adjusting tdc sensor
Cheers

James5

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Re: Advice on engine set up
« Reply #1 on: 08:21, Thu 03 January 2013 »
Quote from: "keirv6"
Just rebuilt my r11 turbo engine and need some advice on the best carb set up ignition timing and boost pressure.
My engine spec
Balanced bottom end lightend flywheel
New pistons and liners piper 285 cam plus vernier
Head ported and mached to inlet alloy inter cooler
Turbo (not realy sure) defo a t2 but has no markings bleed valve fitted

Things I would like advice on
Best boost pressure
Carb jets to suit boost pressure
Ingnition timing to suit above
I have set ignition timing to 9degrees by adjusting tdc sensor
Cheers

If you want to adjust boost pressure i would suggest you invest in a decent AFR wideband kit like the AEM uego before you increase otherwise you may find you have a few problems with the engine due to lack of fueling.  Max boost on a std T2 I would not go beyond 15-16psi and thats bordering it's effiency range.
To get the most out of your engine you would ideally want a full T25 with .49 rear housing that will go well with your 285 cam.  

Ref carb spec unfortunatly I can't say what will suit your engine as all engine's differ, but mod's to the air correcter and 2nd stage are the way to go smaller a/c and larger 2nd stage

Ash-Lee

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Re: Advice on engine set up
« Reply #2 on: 17:09, Thu 03 January 2013 »
As above really, I would also put the advanced timing back to standard, even more so with higher boost.

I've always considered it too much danger for minimal gains.

keirv6

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Re: Advice on engine set up
« Reply #3 on: 19:04, Thu 03 January 2013 »
Engine timing is at 8degrees had to modify flywheel sensor holes

James5

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Re: Advice on engine set up
« Reply #4 on: 09:44, Fri 04 January 2013 »
Quote from: "keirv6"
Engine timing is at 8degrees had to modify flywheel sensor holes

I would put it back to std matey you can get a few deg adv just by swapping the tdc wires around.  Not worth risking matey do you know compression ratio of your engine?  Det could be a problem

keirv6

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Re: Advice on engine set up
« Reply #5 on: 10:38, Fri 04 January 2013 »
Compression should be about standard is 8 degrees not standard setting

Ash-Lee

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Re: Advice on engine set up
« Reply #6 on: 13:21, Fri 04 January 2013 »
I'm confused a little, i've always assumed the following.

Ignition timing - set by flywheel marking and TDC sensor, this is the one I recommeded keeping standard.

Engine timing - set by cam pulley (assuming it's adjustable) I have no experince with these i'm afraid.

Assuming you have used standard parts you should have the standard timings in place by default? Or is the R11 engine different in some way then the R5?

keirv6

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Re: Advice on engine set up
« Reply #7 on: 14:28, Fri 04 January 2013 »
Cam timing was set using vernier and gauge when I checked engine timing with tdc sensor in original place timing was off so altered tdc position to bring back to 8 degrees

Ash-Lee

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Re: Advice on engine set up
« Reply #8 on: 17:28, Fri 04 January 2013 »
Quote from: "keirv6"
Cam timing was set using vernier and gauge when I checked engine timing with tdc sensor in original place timing was off so altered tdc position to bring back to 8 degrees

Just had a look in the Haynes book.

The spec says the ignition timing isn't adjustable, but it should be 8 degrees BTDC, this is measured at idle with the vacumn pipe disconnected.

keirv6

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Re: Advice on engine set up
« Reply #9 on: 19:28, Fri 04 January 2013 »
It's not adjustable because the tdc sensor is fixed if you move the sensor one way or the other the advances or retardes the the timing