David Vizard Interview - Port Velocity Dyno Tests

[Workshop]

David, the flow bench that is in your new porting book, Is it the same Floating Depression one you show in How to build Horse Power of is it a different one? The reason I ask is that I'd like to get on to building my bench in the next couple of weeks... I'm just not in the mood to paint the house yet...

[Rwdfords]

David Vizard said:

Jason,
My fellow tech writer Jim McFarland wrote that story. Has some good info if anyone feels they need to bone up on this subject.
As you staed the burn pattern need to be no pattern but a complete near even coloring of the crown. Getting that is not alway easy but it alweays seems to pay dividends.

One point though is that a centrally place plug is not always best at firing of the charge. A 5 port Mini combustion chamber is (surprise surprise) actually better than most 4 valve heads in terms of effective combustion.

BTW tried those dimples - the better the car/injection atomization the less the dimple do.
DV

Hello David,

Thank you once again for an interesting reply

What is it about the mini chamber vs a 4 valver that makes it burn more efficiently, is it due to better swirl, wet flow & mixture agitation before ignition or does the chamber shape itself and plug location make the biggest difference?

Am I right in thinking the lower the maximum advance needed and a uniform burn pattern the best indicators of how well the mixture is being effectively burned?

Regards
Jason

Edited by Rwdfords on Sunday 29th January 21:10

[84Dave]

David Vizard said:

Jason,
My fellow tech writer Jim McFarland wrote that story. Has some good info if anyone feels they need to bone up on this subject.
As you staed the burn pattern need to be no pattern but a complete near even coloring of the crown. Getting that is not alway easy but it alweays seems to pay dividends.

One point though is that a centrally place plug is not always best at firing of the charge. A 5 port Mini combustion chamber is (surprise surprise) actually better than most 4 valve heads in terms of effective combustion.

BTW tried those dimples - the better the car/injection atomization the less the dimple do.
DV

From the Editors of Circle Track magazine, The book entitled 'Stock Car Racing Engine Technology - Advanced Engine Theory & Design' is definitely worth a read! Jim McFarland's name is on every Chapter. ISBN: 978-1-55788-506-7 .

[packman10_4]

Just reading again David V's book on tuning the pinto yet again , black cover with the Esslinger engine on the front , quite old but very in depth and very intresting. Im building a road going Pinto for a nice mk1 Escort for a friend in Perth WA , spec is

Non injection block (decked)
Injection rods lug removed (ARP bolts)
.05 Mahle standard pistons ( steel strenghing strap inside)
Pistons 10 thou above the deck
Flywheel lightened (ARP bolts)
Bottom end lightened and balanced
10/5/1 cr (due to cast pistons and the oz climate)

Head wise , i think im going for GP1 inlet valve 44.4 mm with as near to 110mm in lenght as possible. Standard size exhaust valve and a towing cam so it will have run out of puff by 6000k but still have plenty of bottom / mid range grunt. Looking for arouind 135hp on a 34/46 DGAV or around 150 using 40's . Trying to find someone to do some headwork to suit , i w / want something that works not something that looks pretty ! Any comments most welcome esp from the Jedi master (David V) and his sidekick ( Dave @ Puma)

[SWR Performance]

packman10_4 said:

Just reading again David V's book on tuning the pinto yet again , black cover with the Esslinger engine on the front , quite old but very in depth and very intresting. Im building a road going Pinto for a nice mk1 Escort for a friend in Perth WA , spec is

Non injection block (decked)
Injection rods lug removed (ARP bolts)
.05 Mahle standard pistons ( steel strenghing strap inside)
Pistons 10 thou above the deck
Flywheel lightened (ARP bolts)
Bottom end lightened and balanced
10/5/1 cr (due to cast pistons and the oz climate)

Head wise , i think im going for GP1 inlet valve 44.4 mm with as near to 110mm in lenght as possible. Standard size exhaust valve and a towing cam so it will have run out of puff by 6000k but still have plenty of bottom / mid range grunt. Looking for arouind 135hp on a 34/46 DGAV or around 150 using 40's . Trying to find someone to do some headwork to suit , i w / want something that works not something that looks pretty ! Any comments most welcome esp from the Jedi master (David V) and his sidekick ( Dave @ Puma)

I had 129 on a build with slightly lower CR, bad ignition curve and stock valves on a 32/36DGAV.. The "towing" cams don't run out of puff at 6K, they easily rev 7500. Atleast mine did.

[David Vizard]

SWR Performance said:

packman10_4 said:

Just reading again David V's book on tuning the pinto yet again , black cover with the Esslinger engine on the front , quite old but very in depth and very intresting. Im building a road going Pinto for a nice mk1 Escort for a friend in Perth WA , spec is

Non injection block (decked)
Injection rods lug removed (ARP bolts)
.05 Mahle standard pistons ( steel strenghing strap inside)
Pistons 10 thou above the deck
Flywheel lightened (ARP bolts)
Bottom end lightened and balanced
10/5/1 cr (due to cast pistons and the oz climate)

Head wise , i think im going for GP1 inlet valve 44.4 mm with as near to 110mm in lenght as possible. Standard size exhaust valve and a towing cam so it will have run out of puff by 6000k but still have plenty of bottom / mid range grunt. Looking for arouind 135hp on a 34/46 DGAV or around 150 using 40's . Trying to find someone to do some headwork to suit , i w / want something that works not something that looks pretty ! Any comments most welcome esp from the Jedi master (David V) and his sidekick ( Dave @ Puma)

I had 129 on a build with slightly lower CR, bad ignition curve and stock valves on a 32/36DGAV.. The "towing" cams don't run out of puff at 6K, they easily rev 7500. Atleast mine did.

The Esslinger engine on the front is actually mine. I had most of it built and Duane finished off the dry sump install. That engine had my cylinder head, cam etc and made a tad shy of 220 right off the drawing board. Duane told me when he flowed the head he had never seen such high numbers. A few years later mu friend David Anton (APT in Riverside CA) built a replica and used it in a pro 4 car. We obliterated the competition including an Esslinger/Ebbling chassis factory entered car that was the last years champ.

[packman10_4]

Hi David , Its great still being able to read the information you gained years ago with the development of the pinto engine its very intresting and a lot better to read than the modern stuff that you get now days. Do you think the Pinto has come on much in the power stakes or do you think there is still some more to get out of the old square dog yet ?

Obviously you are retired now so what have you still got on the go because as we all know once you play with engines you cannot just stop ? With the advantage of full stand alone systems and various throttle body kits plus the CNC stuff it must have opened up a whole new chapter with your various cylinder head and camshaft configurations ?

Im playing with this Pinto at the moment for a friend in Oz , plus we have just had a full LS7 conversion done to a Yellow TVR Tuscan S so once the weather gets dryer we can have a play !

[Pumaracing]

packman10_4 said:

Obviously you are retired now ...

LOL - you funny

[packman10_4]

Pumaracing said:

LOL - you funny

Yea not sure if its a insult or not lol

[David Vizard]

Packman 10-4

No Dave's not insulting you - the point I think he is making is that I would not know how to retire give a 50 page book of explicit instructions. this is how I see it - and I know Dave and many others can relate to this. Every morning I get up - look in the mirror - and thank God I can do just what I please again today - what's that you say? Play with race cars.

If working is having to get up and do something you have to do to put the groceries on the table then technically I have barely worked a day in my life. As for doing stuff I wear myself to a frazzel about every day - sort of like a kid at Disney land.

[David Vizard]

Still with you here Packman10-4 --- I forgot to answer your question (maybe it really is time to retire after all). The last time I had anything to do with building Pinto engines for racing was about 1990 ish. At that time an engine that David Anton and I did put the best the US had to offer into the rear vie mirror so far that they appeard in fornt ready to be lapped (and that was second place at that) which did not quite happen before the end of the race arrived.
do I think I could get more - Hell yes - what's the budget??

DV

www.davidvizardseminars.com

[packman10_4]

Yep thats what i wanted to hear ! still playing and tinkering like you said its great to get up and do what you have been enjoying for so many years and it still pays for the shopping now thats a bonus.

Pinto engine budget lol i wish there wasn't one but there always is , just a strong reliable grunty
motor , for the start i think were going to use the weber 34/36 downdraft and then as funds come more available go for a pair of 40 or 45's . Bottom end is done decked Transit block with 0.5 overbore using new cast Mahle pistons the ones with the steel belt around the skirts. Injection rods with the pin end lug removed and ARP bolts. Lightened flywheel 7lb again with ARP Bolts. All the bottom end is balanced inc the clutch assembly. Cr wise I've gone for 10/5/1 and the pistons are 10 thou out the top of the block. Head wise im going for GP1 size inlets & standard exhaust. Im going to mail Dave @ Puma when were ready for the next stage. Cam wise id like to try the towing cam or torque cam I've read good reports for this. To finish off a 4,2,1 manifold. With this lot id like to see 130 with the twin choke and @150 with 40's.

Giles

[Austinambassador]

DV:- In the search for more power from my Mini engines I first got into the subject of wet port flow back about 1967 maybe 68. All this came to a head so to speak when I became involved as the project leader for the ‘Around America Economy Drive’ project using a Mini as the vehicle of choice. Here, working with several other highly competent engineers, I got to do a significant amount of work studying the effects of mixture atomization and preparation in relation to part throttle fuel economy. The result was a drive, in 1976, around the USA in a 1275 Mini GT with the family and all the luggage needed for a 3 month stay. This was no ordinary creep from point A to point B economy driving and doing so only when the sun was out and the air was dead still. This Mini was road tested by Car & Driver, driven on run flat Dunlops to determine how well they handled both on and off road conditions by Motor Trend and so on. Also I had to bash my way through 3 foot snow drifts in Wyoming by charging them in second or third gear at WOT. Failure to make it through these drifts could have meant freezing to death. I remember arriving in Laramie and noting that there was ice on the radiator in spite of the fact the engine was running. Indeed it was so cold that the heater only ever got to luke warm. All this and our mini averaged 49.88 to the gallon on our arrival back in New York. All this was detailed in one of the big UK ‘How Too’ auto magazines in 1976 – anyone remember it?

Great to hear that the legendary David Vizard has been around here recently. I learned a great deal about engine tech and having a scientific approach to engine testing and mods so thanks Sir Dave!.

I remember reading his 'Round America Economy Mini' series and many other articles of in Cars & Car Conversions magazine. Spent an afternoon re-reading my old magazines and they still make compelling reading - it really was a golden age for motoring journalism with so many great characters like DV about then.

David must have been extremely busy as he managed to combine a 'Spring Clean Service' and dyno tune of his Cortina GXL with preparation of his econo Mini in the June 1976 edition of 'Popular Motorist.

So many question I would like to ask Mr Vizard - who is the dolly bird rubbing cherry blossom black boot polish into the GXL's vinyl roof ?..what happened to the GXL you could have fitted a V6 perhaps ?...and Terry Grimwood and his 'Grimmermobile' ..did he survive painting his mini traveller in his garage without a paint mask!. Is the Lathay Performance centre in Stourbridge still there ?...could you have got more MPG from the mini with more time and funds...