The V8 Owners Forum -

Hi all, i took my car to a RR shootout the other day and am pretty disapointed in the results, i think the carb is way off

can anyone recommend someone preferably in the midlands who knows what there doing with 4 barrels?

What was the result (no need to be shy but also might help diagnose the problem).

Do you have a printout you can stick up and what are the specs of the engine in question

Yeah sure heres the graph

its a 1991 Ford 5.0 HO done about 80k apparently...
its got Trickflow Twisted Wedge ally heads, Trickflow Stage 1 cam, wieand stealth inlet, holley 600 vac secondary carb, fidanza ally flywheel, mustang T5 g'box, mallory unilite dizzy - no ingiton box currently, its running march ally pulleys and still has PAS

all in a sierra shell, its running some crappy bodged headers for clearance reasons, not done by me i hasten to add some of the running have some pigeon poop going on... also one header is a 4-1 and the other is a 4-2-1... i'm gonna get some custom headers made soon.

before doing the mods (heads and cam) the engine went really well i ran a best of 14.2 at the pod i recon'd on around the 230-240bhp mark, my mates XR8 side by side (235bhp) ran 14.7 but no LSD

according to the US stang sites my engine spec should be making 260-320 wheel HP and potentialy over 350 at the flywheel
i realise the US figures are slightly inflated compared to our LOL like most things over there

on the dyno run i used my own wideband (as it was a shootout no AFR on the graph) to log the run, its only connected to one bank but was dipping down to 11:1 AFR at one point. the run was stoped at 5800 as the wheel figure was starting to drop off....

i'm going to fit a new set of leads and a Mallory Hyfire 6 over the next couple of days and also check the valve clearances, i'm at the pod on Sunday to give it a try.

I don't see the problem.
Ford claimes 225 bhp @ 4200 rpm at the flywheel ('91 5.0 HO efi).
Looking to your dynosheet I see the Ford figurs indead and I see that your heads breath better wich resulds are visible with a higher rpm range.

The Wieand intake is just a dual plane with an rpm range till 6000 rpm and with the heads in mind your probably better of with a Torker.

I must say overhere in Holland we stay away of Trickflow Heads, so to speek, we found them tricky ( most of the times in the worst way ). We had better results on the track with the Edelbrock heads ( Fords, Chevy's, Pontiacs ).
Valve clearance @ preload is an issue with the Trickflow heads. They are well know'n for their valve geometric problems.

Trickflow quote 360bhp for an engine pretty much this spec with EFI

a new ford 302 with there inferior turbo swirl heads comes in and 345bhp

even given a 10% bhp US inflation over the UK still puts my engine results miles out

can u point me in the direction of this well known valve train geometry problem? first i've heard of it?