Show Posts

This section allows you to view all posts made by this member. Note that you can only see posts made in areas you currently have access to.

Topics - AC Ventura

Pages: [1] 2 3
Success! A fine spring day in England and perfect conditions to properly test the new improved half tonneau. I like a half tonneau when driving solo. They reduce in car buffeting and make it much quicker to cover up the car when parked. Trouble is, the one supplied with the Mk IV flaps like a dimented bat, even at 25mph.
 So I had a trimmer, first split the tonneau into two halves, then sew in a full length sleeve underneath, next to the zip and into this inserted a 1/4” dia rod, which protrudes at each end of the passenger half tonneau. Between the mirror base and the front scuttle is a barely visible aluminium plate with a hole in that locates the front end of the rod. At the the other end, the rod drops into a recess and simply held down with a cord. No tethers required and it barely moves, even at 70 mph.
 A simple, inexpensive and worthwhile upgrade, with no storage issues.

Endured 300 miles of wind battering on the M1 motorway today, to visit John Sleath Race Cars in Doncaster, UK. He’s an old school knowledgeable engine guy. Has a good rolling road, but it doesn’t offer so called ‘corrected power’ readings, that is rear wheel data converted to flywheel or Dyno equivalents. He says it’s pointless because losses vary between min 20% and 35% and can’t be reliably ascertained. So all his graphs are at the rear wheels. Anyhow, after an afternoon of timing, distributor weight and jet adjustments we improved the low down running and unplugged the power. The new straight through (loud) glasspack exhaust has also made a big contribution. Final figures show car now produces, at the rear wheels, 412ft lbs and 380bhp, which clearly makes Michigan based engine builder and FE guru Barry Rabotnic’s originally dynoed 503 tq /532 hp beyond doubt and pretty good for an OE bore/non stroker, all aluminium 427. Car drove great and has taken me unawares by the seemingly bottomless acceleration into the 6000rpm area. With the old 302 it was all over by 4000. Anyhow, glad I made sure of a long accelerator travel. 😬 😁 😀 Also 17.3 mpg overall on the journey seems pretty amazing for a 7 litre and car ran faultlessly without any dramas. Taken me 3 years to complete the Autokraft Mk IV small to big block metamorphosis, so looking forward to exploring this fabulous combination 😀

PS The new 1/2” higher Blue Thunder air cleaner element gained us 20hp.

Here we are at a theoretical 156mph

7 LTR resting, back home, in our Hertfordshire village, after some unmentionable antics. The big all aluminium 427 is finally rocking and rolling. What an epic piece of automotive legend and a privilege to own in this particular configuration.

Finally, the all stainless headers, 24" mufflers and undercar exhaust system are complete. Thanks to meticulous planning, the original ground clearance has been maintained and there is ample room between the header and the footbox for air flow and heat shielding, despite 1 7/8" primaries, 2 1/2" system. In a RHD car, the motor offset reduces the drivers footwell width by a full 1", compared to LHD, so you need to get your comprises right. Simpson Race Exhausts, here in the UK made light work of the installation and I particularly like the elegant and compact, one bolt jointing system used. Thanks to this the headers can be removed in situ, without removing the steering. Hopefully first fire up, the weekend after this.
Attached Images

Autokraft Mk IV (Cobra) 302 to 427 downgrade 😜

 A year is a long time in politics......also it’s a long time in stupid, crazy, pointless, dinosaur engineering car projects. The first pic is 26 Dec 2017, the last day the original 302, 5L EFI engine was running and the other two, today, 19 Dec 2018. A few more connections before the monster 427, 532 bhp 7L will burst into life. I’m very pleased with my work to date and that I’ve tried to  respect the Mk IV ‘s identity. Wasn’t easy. Expect an undetectable change in the weather, around February 2019.

As of 2.30 this morning, after 7 months of intensive preparation finally, the big 7 litre 427 engine is able to check out its new home.
Thanks to Barry Rabotnic who built the epic motor and all my friends in the FB and other AC Cobra online communities.
Still a lot of work be done, but looks like I won’t be needing a Tesla just yet.


Rare opportunity to acquire this engine at hopefully a bargain price. I suspect the car that the engine is fitted to is unregisterable on the U.K., so a rare opportunity assuming anybody has a use for it. Shelby fitted 428s to the original Cobras. Engine of course needs verifying.

Lot 134 is a 1998 Autokraft Mk III continuation with a 427 engine, similar but not quite the same as above. These cars seem to have difficulty finding the right owner these days, although the original owner owned the car for 18 years. But maybe he was once made of the right stuff, right Steve? 😀😀😀

Does anybody know how to remove the stainless bulkhead pressing at the back of the engine, bay without  removing the body? My engine bay is empty and I have undone the two screws underneath and the heater grommets. It flexes at the bottom, but its still held fast. It seems to be stuck under the hoop that supports the scuttle. If I just pull it will surely bend and distort, so if anybody has any further info, I'd be grateful to learn how its actually attached. If it's just glued for example, I could heat it up. Thanks.

Just another day in the engine shed, preparing for instalation of an all aluminium, Ford 427 FE (big block) side oiler, plus TKO 600 into my ‘93 Mk IV. The project is fraught with technical feasibility issues. Most importantly,  the engine position will be key to minimising the compromises. It will be bad enough doing this once, so it better be right, At the very least, the grp footwells, the engine mounts and some chassis crossmembers need cutting out and replacing, so this kind of caper is not for everyone. All things being equal, I guess it depends on your life agenda: Keep it original at all costs, or experience, maybe improve on the legend?. Either way, it’s worth mentioning that all this can be reverse engineered back, just as easily as it’s been modified.
To be as sure as one can be, regarding feasibility choices, I have meticulously measured the engine and trans in meticulous detail. I’m aware people have done the 427 conversion, but not as far as I am aware with an all aluminium motor and the 5 speed TKO. This incidentally can be had with a extra high 5th for economical motorway cruising. However, I rejected that option in favour of progressive gearing. This is not exactly an economy drive after all.
 Anyhow, I’ve converted the data into a scale CAD drawing, showing how the the car should look with the engine installed. To get it where it needs to be and the vital propshaft angles correct, means positioning the entire 5 foot long drivetrain within 4-5mm. You can see it’s all very tight.....but it might just work. Incidentally the huge 7 litre FE weighs just 20 lbs more than the current cast iron 302. Shelby never had this available, nor ceramic header coatings and that’s the attraction....

ACOC News and Events / Silverstone Saturday
« on: July 18, 2017, 22:52:28 »
Who is actually going to be at Silverstone on the Saturday and on what? We'll be there in AK 1500, my red Mk IV.

Anybody using a 16" diameter steering wheel in their Mk IV?  Mine has a 14" wood and it's okay but looks silly/wrong. I noticed Mota Lita make the same slotted, wood rim wheel in 15" and 16". Looked at pix of original Mk III's and it seems 16" was standard. I've mocked or up and there's enough room.

As many of you may know, apart from being a fairly recent Mk IV owner, I'm also active in the Historic Rally Car Register and run a meeting group on the first Tuesday of the Month at The Gate, nr. High Wycombe.
   Next meeting we are showing Robbie Coltrane's fabulous documentary 'The Ferrari Cobra Wars'. An unmissable film for any Cobra owner. All ACOC members are welcome and there will be no admission charge. Just a great evening with like minded enthusiasts.
   Hope to meet some of you there and below is the programme in detail.
   Regards Mike Spindle
   Berks, Bucks and Oxon Historic Rally Car Register meeting
    Tuesday 7 th February HRCR meeting at The Gate, nr. High Wycombe
   Film Show
   Caroll Shelby vs Enzo Ferrari
   AKA 'The Ferrari Cobra Wars'
   Okay guys......not quite rallying, an indulgence possibly,
   but in reality this is one of motor racings greatest David and Goliath tales.
    In the early sixties Ford USA heard that Ferrari was for sale and were more than interested. However, Il Comendatorre led them right down the (sunken) garden path, until Turin offered to subsidise Modena, which was the purpose of the ruse in the first place.
    Incensed, the suits at Ford wanted revenge, but had nothing capable of beating Ferrari on track
   With the most fortunate timing, race driver and dungaree wearing chicken farmer, Caroll Shelby appeared in Fords Detroit offices with a half baked plan, to drop their new V8, into the English AC Ace sports car. Fed up with being beaten by GM in sports car racing, Ford agreed to supply engines, in the hope that something good might come out of it.
   As most of you will know, that car became the AC Cobra.
   In reality, the ACs aerodynamics were never going to allow them get past the 170-180 mph GTOs at Le Mans. They tried and were humiliated.
   This is story about self-belief. Led 23 year old aerodynamics student Pete Brock, a group of California Hot Rodders, decided they would take on the elite of European motor racing.
   Well produced, with fantastic in depth technical interviews, race footage and soundtrack.
   Narrated with great aplomb by Robbie Coltrane, with input from Shelby's girlfriend,
   business manager and engine supplier arm twister Joan Cole.
   To quote the still lovely Ms Cole
   ‘There was nobody involved with the Cobra Daytona project,
   who wouldn't say, that this was the best of times’
   Meetings are (normally) held first Tuesday of every month at
   The Gate, Bryants Bottom Road, Great Missenden, Bucks, HP16 0JS. 8pm for 8.30.
   To keep these evenings free please come from 7 pm and
   take advantage of our hosts excellent food and beer!
   For further info contact: Mike Spindle on 01923 855891 eves/weekends
   or email:

Pages: [1] 2 3