Thursday, May 31, 2012

Engine swap prep and stuff

Hoping to swap the engines over in my everyday 2500EFI next week after Albany long weekend. I am between jobs -swapping from Canada to Brazil so an engine swap on annual leave seemed like a nice bit of therapy.
I'm going from a ~115bhp 2.5 to a hopefully 165+ bhp 2.1 . Now obviously this won't like 2.5 gearing so a couple of cunning plans have been completed today. Firstly I had a couple of NOS 3.7 CWP off ebay last year - 100 quid each and they were mint. I had one builtup with all new Timken / RHP bearings and new seals this week and will swap over next week.

Part 2 of the cunning plan was to get some decent tyres at a slightly smaller rolling radius - a double bonus of this plan is that I now have some superb rain tyres for the white PI in the shape of Bridgestone RE 002 205/50 R15 mounted on my "spare" 7*15 superlites

I was previously running Sumitomo 195/60 R15 which although good in the dry were HOPELESS in the wet - they spun with ease even with my poor breathless old 2.5. Tonight was the first deluge of winter and even without a chance to scrub them in, the Bridgestones proved almost impossible to spin despite decent provacation - a cheap LSD substitute for the new engine I think!

I will almost certainly be taking these to Albany in case its wet at the hillclimb on Saturday - which seems like a strong possibility. And the gearing change from these two mods - top gear mph /1000rpm has dropped from 20.9 to 18.6 or about 12% - I was thinking of using a 4.11 diff but compromised as its a road car and Australia is flat - if it was doing the 10CR slogging over Alps I reckon the lower diff would be the go.

Sent the torque plate over to Craig Mk3 GT6 in Melbourne this week - then its off to Brisbane for Nicks GT6 engine - anyone else in Oz need it whilst its on a road trip? 

Sunday, May 27, 2012

Albany RTH Scrutineering 2012

In preparation for the annual VSCC Round the Houses weekend - now on the newly named West Australia long weekend
TR4, RS Escorts R35 GTR and my PI

Twin cam prewar Lagonda - must be rare anywhere let alone in WA
WOLF electronic injected 1974 TR6 of Bill Irvine
Works-alike Dolomite
Pauls Roberts newly re-engined sprint and fuel injected Alfa GTAm replica(?)

Pauls Roberts newly Webered engine + extractors

Tuesday, May 22, 2012

Test day and more estate stuff

Managed a late morning session at Wanneroo with Humph after some rebuilding of my metering unit which had shed a few semi-essential parts in its control body. Humph checking his plug colour.

Some fairly interesting beasties out there - including the famous Alfa Chev sports sedan seen here

Nice looking brakes on this GT3 997
Popped into the body shop this afternoon and put the Minilites shod with 195/65 Michelins on the estate - Looks rather good even if I say so myself

Ian the Trimmer just about the finish the new sunroof - hopefully complete by Friday

Thursday, May 17, 2012

PI Estate interior progress

Popped in on Ian "the Trimmer" to see how the PI Estate is shaping up - progress is good - headlining and A, C and D posts are done

Headlining came from Aldridge (thanks for the contact Mike) and seems to fit very nicely - they also supplied enough spare material for the sunroof and sundry bits and bobs

Rather than the early flappy grab handles we have used "rivnuts" and fitted the later handles from a 1977 2500S
D post trim fitted with new material + this shot shows the vinyl trim colour we are using - amazingly its off the shelf leathercloth style which matches the NZ trim collar exactly... which leads me onto the seats.

We have fitted the NZ leather covers to the UK headrested 2500S frames that my PI came with - Ian has made new headrests with matching vinyl - seat need a bit of a clean and feed but leather is supple and stitching excellent.

An here is the rear squab of the estate with the NZ saloon leather modified and fitted - lovely job.
All the vinyl covered cards are made and ready to fit and the carpets are cut using the NZ ones as templates. Work is concentrating on rebuilding and patching up the Britax roof now - I was lucky to get a roll of Dolomite Sprint black vinl roof material in fine grain which will look perfect

Tuesday, May 15, 2012

Tweaking the PI

Just spent a few hours in the shed tinkering with the white PI after yesterdays dyno run.

Adjusted the tappets to 0.010" hot - they hadn't been done since the head was re-torqued when they were set to 0.011 on the inlets and 0.012 on the exhausts - there weren't any horror stories of valve recession even though this new head is not inserted and regularly sees 6500rpm. I use Redline lead substitute and it seems to work. There were minor variations probably due to 6 different pushrods being fitted at the head swap settling into their new homes.

Took off the metering unit and gave the full load screw approx a 1/3 of a turn in which equates to the full load setting going from 0.065" to 0.068" - this should help the top end fuelling/power which was a trifle lean at 13.2 AFR.

Also changed the advance curve on the 123Tune distributor - added 2 degrees advance in most areas so I now have 34deg total advance and added fair bit more between 2000 and 3500 where the engine is off cam and not making good torque - apparently Steve Attenboroughs GT6 with the same cam and similar exhaust responded well to a large increase in advance at low revs.

Advance curve used for dyno run (add 10deg to figures for total advance)

New figure for trialling - note seriously increased lower end figures - will be interesting to road test and see if this works

Just need to confirm what gap to run with the new racing plugs I've been using - NGK B8EGV - I was convinced they would foul but they have been as good as gold. I currently have them set at 0.025" but will try 0.030" and 0.035"

Very tempted to go and see if it makes a bit more power on the dyno with these fine tunings but I think I'll wait until I play with the cam timing - we are thinking about retarding it a couple of degrees to let the power extend to about 6000 but I will be road testing and  adding further adjustments before doing the cam tweak.

Monday, May 14, 2012

Dyno run with new GT head

This has been a long time coming but has been well worth the wait.After waiting for Ken Bryants car to arrive from Bristol last year with a shiney GT cylinder head in the boot I have taken ages getting it fitted and running it up on the Dyno at Tim Slako's.

The graph below shows the back to back test using the new head versus the last run I did in late 2011 where I got 123rwhp. I now have 146rwhp which by any standard isn't a bad improvement for just a head swap - especially considering the old head that came off was "flowed" and had 37.75 and 31.25mm Witor valves.

Estimate flywheel bhp and torque 175bhp @ 5300 and 190lb/ft at 4200

We feel that the dyno gives a slightly pessimistic overall rwhp figure but the difference between the two runs is the obvious thing.

Previous heads power output is the fine line.

CR 10.75 - GTT 43 cam for both runs

Old head with witor valves

Gareth Thomas GTT head with 37.2mm inlets and 32.6 mm GT exhaust valves. Inlet flows around 90cfm at 0.400"-0.450" and exhaust about 64cfm (both at 10inches)

Next modification after using the car for a season or so will be to try the GT 572 cam which uses the Le Mans inlet profile and should add some more top end to give around 200 flywheel hp at 6000rpm. I'll probably wait untl I have forged pistons installed before running this cam with the recommended 11.3 CR