Rollin, rollin, rollin... (road)

I don’t really, 100% know how this science works - but I love it when it does!! :smiley:

I’ll just set my ‘redline’ to 3800 rpm and let the figures speak for themselves…

Max power at 3575 is cool, and bags of torque too. Looking at that I doubt my 1776 would produce more that 90bhp, but the torque is likely to be over 100. Whos 1776 was it.

Alex,

I’m confused how the same engine and carbs produced such different results? Or have you added something else into the mix?

Bob

keith - 2007-05-14 1:04 PM
Looking at that I doubt my 1776 would produce more that 90bhp,

theres one way to find out :smiley:

Righto chaps…

The '98 Pettitt-built 1776cc for Eva had Dell 36’s on stock heads which I knew were well adjusted and running sweet on 122 main jets.

The '01 1966cc (also by Laurie - for Amanda’s Chuckie Bug, commissioned by Jim Murray, bought via Ian, etc.) had Dell 40’s which weren’t so well tuned. Even after Bruce Miller helped me out a couple of years ago, there was a problem with an idle jet, the main jets were too big at 140, accellerator pumps were filthy and air filters needed cleaned. This has all been sorted for fitting to the 1776 for the Bug - another dyno will eventually verify performance later in the year…

For the 1966 in Eva now, all I’ve done is :

  1. Skim the barrel bases by 1.5mm for 0.5mm less deck height with 1mm copper head gaskets (raised compression ratio a notch). The copper head gaskets were required because the pistons were actually touching the heads at 1.5mm off deck height and I couldn’t turn the crank!
  2. Smoothed off the sharp edges and polished the combustion chambers in the stock heads.
  3. Set valve clearance w. swivel foot tappets to 0.025mm w. chromoly pushrods (John Maher doesn’t even set a gap for race engines!)
  4. Match ported Dell 36 carb bases to manifolds (no step out).
  5. Thoroughly cleaned & serviced said carbs with new needle valves, O rings, gaskets, pump diaphragms, etc.
  6. Fitted 128 main jets.
  7. Set idle jets to 2 turns out from fully in.
  8. Fabricated 40mm tall ram pipes (from el cheapo B&Q tapered steel table legs!)
  9. Clearanced and polished inside of ram pipes for smooth airflow into carb venturis.
  10. Linkage adjusted to perfection.
  11. Adapted poor K&N copy paper air filter housings for additional Ram Flo foam filters on top.
  12. Cleaned out fuel tank and filters to & from Facet electronic pump (still goin strong after 10 years use!)
  13. Fitted deep sump and set oil level to bottom mark of dipstick.
  14. Fitted power pulley (no cooling problems anticipated with Porsche fan!)
  15. Bosch 050 dissy with Empi Accufire electronic ignition.
  16. Static timing set to 7.5 BTDC
  17. Bosch W7AC spark plugs - not new, just cleaned up after 4k miles.
  18. Stainless 1.25" exhaust: J pipes (both sides), merged header & dual quiet pack silencers (thanks Bob!)

… er… can’t think of anything else relevant to state of engine tune.

Of that, I expect the key improvements for the power increase are the slightly increased CR, correct carb size, venturi & main jets (for cc at max 4000rpm), some very basic porting & polishing and better state of exhaust tune.

Of course, it could all go horribly wrong tomorrow, but for now I’m just enjoying the results!
With my anorak just off the shoulder, let the reliability trials begin… :slight_smile:

Yep happiest man there yesterday, Van ran sweet Alex, It will give Lee’s cabby a good run for its money now it only ran 106.6 bhp :frowning:

cool mate, looks like your making good torque aswell!! :smiley:

out of intrest where did you go for the rolling road session?? would you recommend??

Falkland Performance Centre - they’re certainly professional and well audited by the industry.
Yeah - I’d certainly recommend them! Private session costs about £50 an hour, but at little as £20 for a power check run on a club day with over 30 cars running. They don’t do carbs unfortunately - most of the cars they dyno these days are just being tested after a re-map.
Ironically for a Subaru specialist, they don’t have a 4x4 dyno, whereas Star Performance in Kirkcaldy do - and they’re VW/Audi specialists!

That is a LOT of torque for a 2 litre engine. Is that figure really meant to be in lb-ft? Nm is more likely and is what they used on the 2005 run for that engine… Would still be very respectable.

What did you polish the combustion chambers with? Looks like Hammerite.

BTW, fitting a Power Pulley is cheating!

:rasp

Ta for comments Nick!
I dunno why they changed from Nm to lbf.ft in 2006 but I think FPC would be found out pretty quickly if they were palming off one figure as the other don’t you? MAHA dyno was re-calibrated in March and is reputed to be more accurate than Star Performance, Dastek & Bedrock!
Combustion chambers were dremmelled - first with wee grinding stones, then smoothed with stainless wire brush heads and polished with compound, felt & cloth heads. Yeah - took me hours…
The peened effect occurred with the wire brushing. Looks a bit rough, but the alloy surface is silky smooth!
Power pulley - only reason this wasn’t on the 1776 case was cos of leakage. It didn’t leak on 1966 case (date stamped '98) so I’m running with it as BAS fan shifts plenty air!

Like the B&Q rampipes…

Will need to have a quite word with you regarding the surface of the cumbustion chambers though???

Nice bhp numbers… got any mpg figures yet???

:smiley: