The V8 Owners Forum -

Hi all, I have been an avid visitor to this excellent site for a while but here is my first post. already had sidecarbods excellent advice on the cobraclub forum and he suggested i pick your brains too!
I have just purchased some peter burgess econotune v8 heads off ebay and they are currently at cylinder head developments in bromsgrove for a check and clean before installation. Have any of you any knowledge of these heads, in particular what I can expect to gain from them? Peters website claims 30bhp? Is there any cheapish but worthwhile mods that chd or myself should do before fitting? or will my current set up need adjusting to take advantage?
My engine is 3.5 sd1, 9;75.1 comp, hurricane cam and eddy 500 carb.
CHEERS, Rob.

A bit more CR would be good, if it can be done easily with a light skim. say 10 to 10.25:1, a thorough debure of the chambers, set the timing up on a rolling road and get the carb set up properly. Get cold air to the carb (you don't say what care it is in but I bet it is a cobra replica). Good headers will help things.
Best regards
Mike

kiwicar wrote:A bit more CR would be good, if it can be done easily with a light skim. say 10 to 10.25:1, a thorough debure of the chambers, set the timing up on a rolling road and get the carb set up properly. Get cold air to the carb (you don't say what care it is in but I bet it is a cobra replica). Good headers will help things.
Best regards
Mike

The pistons are 9.75:1 but that does not mean that the CR will be with these heads. I guess the OP wanted to know some info on these actual heads, like would they have been skimmed ect. Obviously the 'proper' way to go about this is to burette the heads and the pistons at TDC.

On the Cob forum I posted some general info about running flowed heads on smaller engines. Mainly like the fact that they will tend to rev higher than say a 4.6 with the same heads. With this in mind an eye needs to be kept on the revs so as not to over stress other standard components.
At least that is what I found when I took my stage III heads off my 3.5 and fitted them to a 4.6 that I built.

Peter Burgess did appear on this forum a while ago, I guess he will have the low down on the heads.

Peter is far too enthralled with his shiny new RR to partake in forums

If you wanted them tickling or upgrading why didn't you take them to Peter, TBH I wouldn't really take 1 porters heads somewhere else & then ask for his advice seems a bit csneaky particularly in the cloak & dagger world of porting IYSWIM.

I would love to have taken them to Peter but all I really wanted was a clean so I could bolt them straight on cheaply, I got them cheap off ebay(£200) couldnt really afford them but at that price an opportunity I couldnt miss! Chd are just up the road so not a problem to drop off and collect, they are cleaning gasket faces and replacing 2 valves as they failed the vacuum check. I was hoping there would be no additional work required except maybe cleaning inside the ports myself?
What I really wanted to know was will they produce what peter claims(30bhp) as a straight swap or will extra work/components/setting up be required?

It doesnt take a hell of a lot of head work to get 30bhp so I shouldn't imagine you will be far off just by fitting the heads.

Hiya

The Econotune heads usually gain at least 30 bhp at max bhp rpm, above that rpm the increase is even more as standard heads are so restrictive. The power increase is from flow improvements and from increase in CR. To be honest the factory could have done this with better forethought. I do believe you rang us up and asked if they were our heads, you were told to bring 'em up and we would tell you. We are not greedy with prices and it does seem daft to send em elsewhere for checking over if they are our heads afterall we developed them did them and understand why and wot we did.

Am very happy with new dynocom rollers and working very hard to get used to them.

Most interesting thing so far....do plenty of coastdown tests...bhp losses decrease with hot transmissions. So you may think you have 'found' 5 bhp but is just difference in power losses!

Peter

Peter,

That is interesting, we have regularly found a tenth or two on the strip once the first pass is out of the way. I always assumed it was from getting the gearbox and diff up to temperature, your finding confirms it. letting it rotate the tyres and running through the box on stands helps a little but it will generally still pick up a little on the second pass. After that it runs pretty much the same all day if left alone.

Alan

Hi Alan

Exactly what we were thinking....it would be worthwhile for sprinters/hillclimbers/drag racers to get the thinnest oil that would be safe in the transmission and engine. The other thoughts are warming things up first, I understand some emergency service vehicles a
have plug in heaters to keep all the oils warm and ready.

The other thing we are surprised at is the loss of bhp with reduction of tyre pressure....dropping from 32 to 19 on my little Jimny sapped 4 bhp from the power and it only had around 70 at the wheels to start with !

Peter

again I agree with your findings, in the end everything affects the performance. Slightest difference in temperature anywhere in the car Will make a difference. Peter you are an asset anywhere you go.

Thanks

Alan

In Scaninavia an Canada (and probably many other countries) you can get sump heater kits to keep the oil warm overnight when it gets silly cold, you find a mains outlet at every bay in many carparks so you can plug in when you park. You can also get kits for generator sets so they will start first crank when needed.
Best regards
Mike

I used to race Landyatchs - being only powered by the wind we search for every performance gain we can. One good gain was running in the wheel bearings with metal polish for a few miles to polish them up - then running them with machine oil rather than grease. If you spun a wheel on an axle you could come back to it after making a cup of tea and it would still be spinning. Likewise an out of balance wheel uses more energy.

Every component in the drive train will take energy, propshaft UJ's, support bearings, even the rubber seals on the bearings. Every component needs to be spotlessly clean and free to turn or move with mininal resistance for optimum performance - obvious - but how many of us accept that brakes drag a bit - jack your car up and give the wheels a spin - chances are every corner takes a slightly different effort to turn a wheel - they should be the same side to side and be minimal - A lot of cars will have calipers not returning sapping huge amounts of power but you would not accept a rubbing brake pad on a push bike would you

I wonder if with a suitable sensitive dyno if you could measure the power used by an incorrectly tensioned fan belt. At 7500 I bet disconnecting the feed to the alternator could be measured.

Andrew

" One good gain was running in the wheel bearings with metal polish for a few miles to polish them up - then running them with machine oil rather than grease."
I used to do this on skateboard wheel bearings, we also used to grind up 4B pencil leads for the graphite and run the bearingd dry with only the graphite as lubricant.
As you imply all the little bits add up.
Best regards
Mike