Rolling road

[Anonymous]

I've just had my car on the rolling road and have 2 points of poss. interest for peeps.
1. The rolling road gives out a speedo reading. My car runs on 16" rims (195/45) and showed 62mph when the rolling road was indicating 60mph. Most cars show a speedo reading of 10% over on standard rims and tyres.
2. My car is the one written up elsewhere on the site (1.6 conversion + twin 40's) I've now had a Blydenstein conversion done to the head (larger inlet and exhaust valves) the previous max power was 116bhp(flywheel) at 5600rpm. With no other significant changes it is now showing 150bhp at 6000rpm. I make that a 30+% gain from the headwork.
Only trouble is I've now got valve bounce at 6500rpmx-(

[Anonymous]

PS I would recommend the rolling road operator Peter Baldwin at Wilshers Garage Wimpole nr Cambridge 01223 207226. You can take full part in the session and he's very interesting and knowledgeable.

[Anonymous]

Doh! Thats 20% gain not 30:D

[Anonymous]

My speedo was less than 1 mph out at 70 mph..and that was on 195/45/15

[Anonymous]

1. the low profile tyres you have mean the actual rolling radius of the wheel is not much larger than 165/60 R14 (sdtandard Nova wheels) so the speedo should not be very far out (which yours is not)

2. Thats a nice hike in power for just a head mod! I have 1400 with twin 40s, rally cam, flowed head and it gets 114BHP at the fly so it seems to add up right to me!!!!


knowley@globalnet.co.uk

[Anonymous]

I was lead to believe that by the wheel vendors but I have measured the standard 165/60 R14 thats the spare as having a circumference of 770mm approx. The 195/45 R16's measure 865mm. Thats 10% extra

[Anonymous]

150bhp, nice one! How much for the head?

[Anonymous]

?330 excl. VAT X-( but you can't fault the work. There is alot involved in porting out round the new valve seats and the inlet and outlet tracts as I did some of this myself and it takes ages. For this money apart from the new larger valves (1mm bigger alround) and seats you also get new guides and the inlet valves are profiled down. The whole thing is chemically cleaned and all important internal surfaces as well as the exterior is fine beaded blasted which looks the business. The head is also lightly skimmed ready to go back on. All that needs to be done when you get it back is to lap the valves in.

[Anonymous]

i got a blydenstien b+ head on me 1.4sr that was ?500:o

[Anonymous]

My head was fully stripped down and clean. I had ported out the exhaust and inlet tracts already (relatively easy on 1.6 head but pretty difficult on the 1.4 cos of the protruding water galleries)so i got a discount.