The V8 Owners Forum -

Hi all you may have seen my car in PPC its the one that only made 241bhp
Well thought i tell you all about the latest mods
Ive had the cylinder heads rebuilt,ive fitted a Mallory dissy with a MSD
should have my new Nos hit this week from Wizards fo Nos, ive gone for a spider plate with a street max controller 250Bhp max at mo need to change axle and box if i going to put more through her
Shes booked on TCS rolling road on Wednesday to sort out carb, i have not had time to sort the exhaust yet, thats first on list after Retro car day at Santa Pod iam hopping she will make 300bhp even with the exhaust as is.
only problem is she not running yet the second hand MSD i bought off Ebay
don't work so of to Real Steel Monday morning to get MSD tested
If any one is near Tcs on Wednesday pop in you might see a grown man cry there just off junction 8 M11 near Stansted
When i can remember how i will post some picks

Well done mate!
Not long now until you can do some baseline runs at the Pod eh?
That car has got shed loads in her to be unleashed.

Thanks Perry for all your help and ideas for nos kit

Hi at she runs again at last
Only got her running about half 9 last night after a trip to Real Steel to buy a new MSD the one i bought off Ebay for £50 was fried, should have known you never get anything cheap, that's any good
While i way there i bought a MSD timing retard unit for my nos kit (when am i going to stop spending on her) i sold my Lovely Audi S4 to fund this lot of mods
Since last time on rollers when she made 241 bhp and 350ft lbs of torque
i have had the heads rebuilt fitted a Mallory Uni-lite Msd Blaster coil and MSD6al
with the alloy con rods she revved quick before even with ignition problems But now she revs like a bike engine believe me
I am off to rolling road tomorrow and so hoping for some good figures
she going on the same rollers that were used for PPC Rover shoot out

shame i cant make it to see it on the rolling road, im down at j7 of the m11

Good luck today Rich - hope it makes the numbers

Whatever it does don't forget to use the Will Holman PPC conversion factor

Divide by 289 and multiply by 300

My G27 develops - 241 Holman BrakeHorsePower

And yours was at - 250 HBHP so not so far to go

Andy

Any news yet Rich???

Hi back at last she made 276.2 bhp at 5400 rpm thats up 36 bhp from the ppc day but was making 220 bhp at 3500 and 350 ft lbs of torque
I know my exhaust is holding her back but by how much? and am wondering if the cams to big dont forget she only 7:1 cr
we do i go from here? any ideas

Hi Andy just worked it Wills way 286.7 Getting there???

Thats sounding more like it mate

Tricky wrote:Hi Andy just worked it Wills way 286.7 Getting there???

- great for down the pub that Holman horsepower factor

Rich those headers strangle a standard 3.5 engine - goodness knows what they are doing on yours. You will probably need 1 5/8 primaries into a pair of 3" collectors - I run 1 1/2 on mine into twin 2.5" collectors and they are on the limit really and will hold my engine back if I increase the capacity.

As a quick and dirty calc the Exhaust primary should be about the same size as the exhaust valve. - A more exact calc says 1.67" ID. for your car

As for CR I have a calculation in an old Vizard book that I will dig out - pretty sure you will be at least 10% down on power probably more.

You could easily be 30-40 HP down due to those issues.

Andrew

Tricky,

Refresh my memory, only 7/1 comp ratio, is this static or dynamic? and whats the cam?

It's obviously costing you a lot of power, are the pistons specifically low compression with a view to super or turbocharging?

Kevin.

Hi Kevin

The cr is static
she runs a 256 mechanical cam she was built to be charged,

i am only running 1" 5/8" headers at the momment i know thats not helping but by how much?

have mesaured up and think i can get a 2" set in but is that to big?

I only got her back on the road in March after nearly 5 years so the planed twin turbo conversion will have to wait its so good to have her on the road again
I have just purchased a spider plate nos set up which i some how will get fitted before Retro car show

Rich - are you sure about those headers being 1 5/8 - from memory they were block huggers which are usually 1 3/8 OD

You need 1 5/8 ID which would be 1 3/4 OD - which should be more than adequate.

Andy

Tricky,

Are you sure it's a H256 as thats a full race cam and not one which would have been suitable for forced induction, the power range is 4000-8250RPM which doesn't reflect your rolling road results.

The event periods for that cam are 48/76 87/43 with a LCA of 104 deg. and thats Massive.

Re the compression, if the static is only 7/1 then with that cam the dynamic is going to be way down probably sub 6/1 and that has got to losing you shed loads of power, it is said that a raise in CR from 9/1 to 10/1 will yield 10-15 additional BHP so you could be up to 60 BHP adrift if that is the cam you have got.

Any top end figures will of course be highly dependent on the fuel delivery and exhaust systems.

If you do have block huggers they are usually small bore and highly restrictive even on a modest engine, measure the OD and see what you have and ideally you do not want a sharp bend immediately after the flange, do you know your exhaust port dimensions, ideally the primaries should be slightly larger to resist exhaust gas reversion.

Kevin.