Post your dyno curve here

[phazed]

Richard, I reckon your cam timing needles retarding by a 2 to maybe 4 degrees to give you more midrange but of course you would loose a little top end.

Mine needs the opposite, sacrifice a bit of midrange to push max power further up the rev range.

[db484bhpv8]

phazed said:

Richard, I reckon your cam timing needles retarding by a 2 to maybe 4 degrees to give you more midrange but of course you would loose a little top end.

Mine needs the opposite, sacrifice a bit of midrange to push max power further up the rev range.

I need to know more of these cam timing needles you speak of

[ClassiChimi]

That's very interesting Chilli, are the forged pistons heavier
What's your set up Daz,, you really have one of the best N/A engines around.

Maybe the mappings working better on Daz car Richard ?

In the real world there's probably a tenth or two in it
Be a great Drag race between you two !

I'm starting to wonder if all the effort to tune the n/a engine is worth it,
Turbo or super charger and your gonna be in the 400 + bhp easy

I've sat and read all the posts on this thread, excellent stuff.
I live and learn chaps.

[Sardonicus]

ChilliWhizz said:

Daz, what cam and heads have you got? Our figures are quite similar, I've got 14 more bhp but you have 12 more lbsft...

What's particularly interesting is that at 3k rpm you have 200bhp compared to my 175, and 350 lbsft compared to my 290

Then at 4k rpm you have 270bhp and I have 260, and you have 360 lbsft and I have 340.....

OK, appreciate different RR's, but on paper it looks like I've sacrificed a shed load of mid range power and torque for a few extra willy waving bhp at the top end.. In fact it's not till we hit 5k that my bhp starts to edge ahead.... We may have the same heads (V8D stage 4), but based on your figures it doesn't look like my (differences to your build) bespoke cam and triple plenum are doing me great favours..

Hat's off to you though, that's a strong (power and torque) engine you have there

Chilli (slightly disgruntled. maybe even a bit upset... definitely not happy)

Chilli put those differences into a percentage you'd barely notice the difference in real world conditions and I doubt this is a mapping issue more likely down to how a combination of parts all work together you cant have a combination of engine goodies that all work in harmony right through the rev range the biggest show stopper is the camshaft of course I am not denying you can loose out due to poor mapping but if these voids in the map have been over looked due to ign timing etc then maybe the mapper needs to find another occupation

[OleVix]

phazed said:

Richard, I reckon your cam timing needles retarding by a 2 to maybe 4 degrees to give you more midrange but of course you would loose a little top end.

Mine needs the opposite, sacrifice a bit of midrange to push max power further up the rev range.

Its the opposite, retarding gives high rpm hp, advancing gives more torque lower down

[Sardonicus]

OleVix said:

Its the opposite, retarding gives high rpm hp, advancing gives more torque lower down

Not necessarily dial out 10 degrees of max advance and see your BHP plummet no one size fits all remember

[SILICONEKID345HP]

Chilli was yours mapped on the road ? If so why not take it to some where else ?

Sorry i niggled you

[phazed]

OleVix said:

phazed said:

Richard, I reckon your cam timing needles retarding by a 2 to maybe 4 degrees to give you more midrange but of course you would loose a little top end.

Mine needs the opposite, sacrifice a bit of midrange to push max power further up the rev range.

Its the opposite, retarding gives high rpm hp, advancing gives more torque lower down

Im no expert and are learning all the time.

In fact that's what I thought but was consequently told the opposite recently.

Interesting article here. Follow the photos, there is dialogue on each one.
Shame they didn't show results when retarding a cam.

http://www.hotrod.com/how-to/engine/mopp-1211-degr...

Interesting article here as well, better make a coffee first!

http://www.austincc.edu/wkibbe/camtheory.htm

[Sardonicus]

phazed said:

Im no expert and are learning all the time.

In fact that's what I thought but was consequently told the opposite recently.

Interesting article here. Follow the photos, there is dialogue on each one.
Shame they didn't show results when retarding a cam.

http://www.hotrod.com/how-to/engine/mopp-1211-degr...

Interesting article here as well, better make a coffee first!

http://www.austincc.edu/wkibbe/camtheory.htm

Just to add to this I should of said previously correct cam timing on install is imperative IMO especially the more severe the grind and can make or break good torque and HP figures

[db484bhpv8]

Sardonicus said:

ust to add to this I should of said previously correct cam timing on install is imperative IMO especially the more severe the grind and can make or break good torque and HP figures

Will be doing mine this Friday. Whats the worst can happen?
Seriously though i wouldnt mind a pointer or 3

[HarryW]

Sardonicus said:

phazed said:

Im no expert and are learning all the time.

In fact that's what I thought but was consequently told the opposite recently.

Interesting article here. Follow the photos, there is dialogue on each one.
Shame they didn't show results when retarding a cam.

http://www.hotrod.com/how-to/engine/mopp-1211-degr...

Interesting article here as well, better make a coffee first!

http://www.austincc.edu/wkibbe/camtheory.htm

Just to add to this I should of said previously correct cam timing on install is imperative IMO especially the more severe the grind and can make or break good torque and HP figures

I had a standard H218 grind in my V8S rebuild, dialled out by 2 degs from straight, it made 275hp 285lbs and revved out to beyond 6k rpm, not bad for a 4ltr. I think one important point is to not overdo the advance retard if you are relying on pocketed Pistons, don't want it too far out of sync.....

[HarryW]

db484bhpv8 said:

Sardonicus said:

ust to add to this I should of said previously correct cam timing on install is imperative IMO especially the more severe the grind and can make or break good torque and HP figures

Will be doing mine this Friday. Whats the worst can happen?
Seriously though i wouldnt mind a pointer or 3

A good home build tdc tool is to hollow out an old spark plug and have a welding rod sticking through resting on top of the piston, easy to see tdc, or put a gauge on the tip if you want.

[ChilliWhizz]

phazed said:

Richard, I reckon your cam timing needles retarding by a 2 to maybe 4 degrees to give you more midrange but of course you would loose a little top end. Mine needs the opposite, sacrifice a bit of midrange to push max power further up the rev range.

Peter, I'll try and get some input from Rob, it's probably about time the engine had a good health check anyway

ClassiChimi said:

That's very interesting Chilli, are the forged pistons heavier

I dunno Alun, sorry.. they're definitely noisier though!

Sardonicus said:

Chilli put those differences into a percentage you'd barely notice the difference in real world conditions and I doubt this is a mapping issue more likely down to how a combination of parts all work together you cant have a combination of engine goodies that all work in harmony right through the rev range the biggest show stopper is the camshaft of course I am not denying you can loose out due to poor mapping but if these voids in the map have been over looked due to ign timing etc then maybe the mapper needs to find another occupation

It was mapped by Shaun mate

SILICONEKID345HP said:

Chilli was yours mapped on the road ? If so why not take it to some where else?

Sorry i niggled you

Yep mapped on the road Daz.... and you didn't niggle me at all

The question remains.... why does my engine appear to be the only one on this thread that has a torque figure lower than its bhp figure... and by quite a margin looking at other dyno's

Thanks for the input chaps
Chilli

[Sardonicus]

ChilliWhizz said:

Yep mapped on the road Daz.... and you didn't niggle me at all

The question remains.... why does my engine appear to be the only one on this thread that has a torque figure lower than its bhp figure... and by quite a margin looking at other dyno's

Thanks for the input chaps
Chilli

Sorry Chilli was not having a pop at your mapper just meant that an engine mapped poorly you can lose out and your question maybe down to nothing more than cam timing the recommended figures on the cam card are just that one figure does not fit all its just a base, after all is the hot cam being fitted to a 3.5/4.0 slightly breathed on or an engine like Peters full house 5.5 thats a massive variation trust me

Edited by Sardonicus on Monday 9th March 13:35

[phazed]

As Shaun mapped your car Richard, I'm sure it's all good.

Mapping on a RR may give you a couple of extra horses, maybe not.

My experience of Shaun's mapping is all positive.

You need to speak to Rob.

It could all be down to the grind but again, it could be a timing issue that could be improved upon.

As to your noisy pistons, that's just valve train clatter echoing in the triple plenum imho.

when are you around my way?

We could do a back to back!

[ChilliWhizz]

Sardonicus said:

Sorry Chilli was not having a pop at your mapper just meant that an engine mapped poorly you can lose out and your question maybe down to nothing more than cam timing the recommended figures on the cam card are just that one figure does not fit all its just a base, after all is the hot cam being fitted to a 3.5/4.0 slightly breathed on or an engine like Peters full house 5.5 thats a massive variation trust me

Hi Simon, I didn't take it the wrong way I hear what you're saying about cam timing, and understand, but it'd be unlike Rob to incorrectly dial in one of his own grinds..

phazed said:

As Shaun mapped your car Richard, I'm sure it's all good.

Mapping on a RR may give you a couple of extra horses, maybe not.

My experience of Shaun's mapping is all positive.

You need to speak to Rob.

It could all be down to the grind but again, it could be a timing issue that could be improved upon.

As to your noisy pistons, that's just valve train clatter echoing in the triple plenum imho.

when are you around my way?

We could do a back to back!

Agree regarding Shaun, will be speaking to Rob (hopefully), yep very noisy through the thin CF, sometimes I think there's a bag of nails loose in there

Not sure when I'll be in sunny Surrey... I'll drop you a text/mail/call when I know... Presumably by back to back you mean RR? or compare noisy plenums

[phazed]

Or just swap cars and have a little drive?

[ChilliWhizz]

Nice idea Peter, but I think I'd be worrying about swapping ends in yours

[phazed]

ChilliWhizz said:

Nice idea Peter, but I think I'd be worrying about swapping ends in yours

Honestly, it's like a pussycat, miowwwwww.

[Sardonicus]

ChilliWhizz said:

Agree regarding Shaun, will be speaking to Rob (hopefully), yep very noisy through the thin CF, sometimes I think there's a bag of nails loose in there

Not sure when I'll be in sunny Surrey... I'll drop you a text/mail/call when I know... Presumably by back to back you mean RR? or compare noisy plenums

No your not getting me concerning timing the cam most of us just fit the cam at the manafacturers recomended settings it dont mean that thats the optimum for a given engine spec safe but not optimum put it this way the Rover is to hard to swing the cam timing even if you wanted its to much of a palaver stripping down the front end of the motor