Rolling Road Tuned At Skip Browns - Not What I Was Expecting

[sam jfm 0]

Right, just got back from skip browns after having my car setup. It didn't really make the sort of power i was expecting (73 bhp i'm not sure if that's at the wheels or fly how does skip measure it??), but nothing seemed to be wrong with the car and it drives quite well. now im just going through the process of seeing if something is not quite right or maybe thats what it should be putting out? so i will list the spec i have ( i bought the engine SH so i am just going on receipts)

 

now it has:

 

Twin 40 weber carbs

a piper cam demon tweeks stock number PIPKBP13270

vernier pulley

"flywheel dynamically machined and balance crank and clutch"

gas flow cylinder head

 

 

What would you expect? i was thinking 100ish?

 

BTW i'm not a bhp collector i dont really care what it makes as-long as its making what it should-ish

 

Cheers sam

[chrisj21 2]

Some more information may help.

 

Engine size?

[sam jfm 0]

good point. 1360 tu

[boldy205 74]

Poss measured at wheels, not the fly, so 73 is prob about 100 BHPish? (best not to start asking people on here how much BHP is lost in trasmission, it tends to get ugly! )

The best person to talk to is Skip Brown though, seeing as they tuned the car.

Matt.

[peakrevs 0]

Right, just got back from skip browns after having my car setup. It didn't really make the sort of power i was expecting (73 bhp i'm not sure if that's at the wheels or fly how does skip measure it??), but nothing seemed to be wrong with the car and it drives quite well. now im just going through the process of seeing if something is not quite right or maybe thats what it should be putting out? so i will list the spec i have ( i bought the engine SH so i am just going on receipts)

 

now it has:

 

Twin 40 weber carbs

a piper cam demon tweeks stock number PIPKBP13270

vernier pulley

"flywheel dynamically machined and balance crank and clutch"

gas flow cylinder head

 

 

What would you expect? i was thinking 100ish?

 

BTW i'm not a bhp collector i dont really care what it makes as-long as its making what it should-ish

 

 

 

Cheers sam

 

 

I'm sure you are disappointed at that figure which should, I would have thought, be significantly higher than that of the standard engine. However,I wouldn't place too much reliance on the output figure because there are too many variables. Power is measured at the wheels. Apart from the calibration of the equipment which may or not be accurate it also depends on losses down the transmission line and your gearing. For example, you will get a higher figure in third than in fifth. I know of quite a well known rolling road where the guy sets his calibration high so that everyone goes away very happy. I took my standard MK11 Golf GTI there and it came away with more power at the wheels than was claimed by the makers at the flywheel.

 

I think the main thing is that following your session on the rolling road, you can feel an improvement in the way the engine runs. If it has made a difference then it has been money well spent.

 

John

[sam jfm 0]

Skip brown suggested that the cam timing could be out but he didn't think he could get much more out of it and he or i dont know the spec of the cam. the only reason im interested in the power that i would like to make sure im getting the most out of the engine i can, its a competition car after all so every little helps.

 

there is an LSD in the gearbox would that make a difference?

[jonnygoodhand 0]

My first visit to a rolling road (Aldon), went very similar to this. The guy told me it was 74bhp, which I naturally thought was at the wheels, but turned out to be at the fly.

 

Engine spec (suppposedly) was near identical to yours too:

1360 TU

Twin 40s

Piper 285

 

Afraid I never quite got to the bottom why. Ended up having a new engine built.

[sam jfm 0]

Lol just what i wanted to hear

[jonnygoodhand 0]

Lol just what i wanted to hear

 

Now I come to think of it, mine didn't feel particularly lively and wouldn't rev above 5k:

 

 

The engine did have dubious origins, so there was probably plenty wrong with it...

[pug_ham 242 3 Cars]

a piper cam demon tweeks stock number PIPKBP13270

P13BP270

• Rev range; 2000- 6500
  
  
• Power increase; 10 BHP
  
  
• Duration; 268 deg 268 deg
  
  
• Valve lift inlet;0.340" 8.64mm.
  
  
• Valve lift exh; 0.340" 8.64mm.
  
  
• Full ift, Inlet ATDC; 109 deg
  
  
• Valve clearances; Inlet; 0.010" / .25mm Exh; 0.010" / .25mm
  
  

Piper cam kit 13BP270 info

 

It does sound quite low for the spec of your engine with what you say has been done but you need to ask them where that figurei is quoted for, wheels or crank (which is guess work imo).

 

Graham.

[burr_2000 1]

Is it the old type 1360 tu engine (TU3S), If so the Low comp pistons and head wont be helping, But if its 73hp at the wheels then its not bad. I dont suppose you have torque figures?

[sam jfm 0]

I will ring skip brown tomorrow and find out where he measures it, no i dont sorry

[pug_ham 242 3 Cars]

Is it the old type 1360 tu engine (TU3S), If so the Low comp pistons and head wont be helping

I'd have to hazzard aguess that whoever did the head work would also have skimmed the head sufficiently to raise the c/r up to allow for the cam.

 

Who did the work to the head? Might be worth asking them if they skimmed it etc & all the valve clearancces are set correctly.

 

Graham.

[sam jfm 0]

The figure is at the wheels so its not as bad as i thought!

[welshpug 1,627]

not a bad gain, probably more to get if you set the cam timing properly, valve clearances on these are a doddle to sort, setting the cam timing is relatively straightforward as well though you will need a dial gauge.

[McDude 33]

SBC definitely measure at the wheels.

 

When I went there they reckoned that on their rollers a good standard 1.9 8V would make ~105BHP, so 73BHP for a 1.3 seems pretty good to me.

[drmo 5]

106 rallye/xsi head with bigger valves would surelly help, and also tu3 silvertop pistons which top up the liners (tu3s don't and to make the case even worse, they are dished). Dont forget the cam is quite mild. With well set up webers it should make cca. 110bhp at the wheels.

 

This is how the pistons look like:

Edited February 4, 2010 by drmo