CPO 451L - Manta A V8 Modified

Owner: Paul Holtom

Many people have commented on how stock/ unmodified the car looks, yet hides so much, with none of the original drive train left.

Modifications and problems encountered

A problem was encountered after lowering the front anti roll bar for clearance under the bell housing. When held in the new lowered position the bar moved forward very slightly but enough to increase the front wheel castor angle.

 The Manta A anti roll bar has two functions one to reduce the roll rate and two as a track control arm locating the front lower control arms in the fore and aft plain. This small increase in castor caused the front wheels to be dragged across the ground whilst in a reverse turn, which resulted in the front tyre on the outside of the turn contacting the front lower panel and bending it.

.  For an extreme example of excess castor think of the angle on the front wheel of an “Easy Rider” style 70s chopper bike with the rider sitting on it and the front wheel on full lock to restore the castor angle to the original setting adjustment needs to be carried out to the front upper control arms moving them forward by the same amount. This was carried out by inserting some shims on the securing bolt thereby moving the control arms forward.

Point to note make sure the lowering blocks do-not allow any fore or aft movement in the anti roll bar within the rear rubber mountings. Due to my positioning of the engine I had to make some heavy mods at the front of the car for the radiator and air flow. First the body cross member was removed and the chassis legs extended with box tube to the front panel behind the entry holes for the front bumper mounting irons. More box tube was then welded into position joining them across the car. In turn this was welded to the remaining part of the front panel as can be seen in the photo (right) above the front spoiler. A second cross member was then added between the two chassis leg extensions to form the radiator support. Triangular shaped supports were then added between both cross members to restore strength

Cooling:

The radiator is an Opel Monza heavy duty (air conditioning equipped) item, with the bottom hose outlet moved from the side of the radiator to the rear to suit the application.

Wheels and Tyres:

When first returned to the road after modification I used the Commodore B 14 by 6 inch steel sport wheels which I gave the car a street sleeper look. Since then I have fitted 15x7 Compomotive ML alloys with 205/ 55 profile tyres.

Exhaust:

Custom manifolds with ceramic coating, with custom twin pipe system in stainless

The axle case was narrowed as the Manta `A` is somewhat narrower than a Commodore; new half shafts were ordered through Hauser Racing of Northants and made in the USA by Moser engineering.

Servo and master cylinder have been relocated forward and to the right for clearance.

Suspension:

I have modified the instrument panel to incorporate a complete set of Autometer instruments, including an electronic speedo, which can be calibrated form the driving seat if necessary on changing wheel or tyre size.

Additional information:

The engine has torque and power in abundance, which can cause some surprise to the hot hatchback drivers who try to be first away at the traffic lights. The manta A is rare car on the roads in the U.K. today. I have been asked by young people (too young to remember the Manta A) if they were all V8's.

I had the privilege of driving this monster V8 A series in June 2004, to sum this car up it's a work of art and goes like a bat out of hell............Robbie  .......webmaster