Archived Message
RV8 Bonnet Required
As a result of bonnet clearance issues on a V8 conversion, would anyone have any info on the availability of an RV8 bonnet? NB: Steel not fibre glass! Thanks in advance for any info.
Pat Boghossian
21/06/2012 @  20:33
Under topic: RV8
Archived Reply(ies) received for this Message
RV8 Bonnet Required
Part number ZKC5425, have you tried these suppliers?
British Motor Heritage Limited
Mech Spec
Brown & Gammons
Clive Wheatley
Geoff King
22/06/2012 @  07:26
RV8 Bonnet Required
Thanks for the sugestions, however, have already exhausted all the usual suppliers (noting BMH does not sell panels direct to the public). Hoping someone might know of a secondhand one somewhere! Hens' teeth would probably be easier to find..... For info, BMH will let me know on Monday if they intend to make any more.
Pat Boghossian
22/06/2012 @  22:35
RV8 Bonnet Required
Pat, have you thought of contacting the guy selling the spares or repair RV8 on ebay? The bonnet looks in repairable condition.
Michael O'Leary
24/06/2012 @  07:43
RV8 Bonnet Required
Michael, unfortunately he's not prepared to sell the bonnet separately.
PAt Boghossian
24/06/2012 @  21:15
RV8 Bonnet Required
Pat, a couple of ideas to throw out there... Do you particularly want the look of an RV8 bonnet or are you sourcing one out of necessity for clearance reasons? If you are fitting an EFI system to your car you could consider changing to a federal style plenum. This would allow for the use of a standard bonnet silhouette?

Contrary to popular belief, A C bonnet isn't an option on EFI cars with the usual RR / SD1 type plenums. A pal of mine has a C bonnet fitted to his EFI converted GT. He had to panel beat an extra tear drop into the bonnet to clear the plenum.

Actually, there's a thought... could you look to sourcing an ally bonnet and have a coach builder beat and shape a suitable bulge a la RV8 style?
JC Moulds
25/06/2012 @  08:14
RV8 Bonnet Required
John, in answer to your question 'yes' and 'yes' ie: we like the look of the RV8 bonnet and we need to use it for clearance issues. I'm acting as 'advisor' for a friend of a friend who is doing the conversion almost 200 miles away! So not as convenient as being able to pop over and seeing exactly what the problem is, however, I know he's using a Holley / Offenhauser set-up and with a 14" 'low-rider' air filer it'll all fit nicely under the RV8 bonnet as this was my set-up on my conversion....back in 1994! I know some people use the tiny 6" filter just to make it fit under the standard bonnet but it ends up starving the engine of the air it needs to function properly. However, I do like the idea of sourcing an ally bonnet and forming an RV8 style bulge in it...... I know just the person for that but he's not cheap! I'm still keeping my fingers crossed in anticipation of BMH confirming (hopefully later today) that they will be making another batch of RV8 bonnets.
Pat Boghossian
25/06/2012 @  18:00
RV8 Bonnet Required
The Offenhauser 360 manifold is just about the lowest inlet you can get for a RV8. I'm surprised that your pal is having issues getting everything under the standard bonnet? If your pal plans to use a 14" air filter then there may further clearance issue to consider in that the outer edge of the RV8 bulge is not much higher than the standard bonnet silhouette anyway - we're talking only a few mm. Please see these two images of this factory V8 race car to illustrate the issue. On this car, the carb is raised by a 1" phenolic spacer block which necessitated cutting a 14" round hole in the bonnet. Note how negligible the difference between the hight of the bulge at the extremes of the air filter vs the hight of the standard bonnet line.

The key issue in generating suitable clearance on these kind of builds is in the air filter base. You need to source a suitable "drop base" i.e a base that allows the air filter to sit around the carb rather than on top of it.

I have an Edelbrock performer inlet manifold on my factory V8 which is a fair bit taller than the offy 360 that most folk choose. I had to purchase a suitable drop base and then dress the leading edge down further with a "Birmingham screwdriver" in order to generate suitable clearance. As a result, the nose of the air filter on my car sits about 5mm lower than the rear but the bonnet does close and a recent rolling road session suggests the setup is working well. If you would like me to take a couple of photos of my setup to pass on I'd be more than happy to do that if it will help?
JC Moulds
25/06/2012 @  20:15
RV8 Bonnet Required
A little off subject, but years ago I put a replacement standard bonnet on a factory GT V8 only to find two dents appear where the tops of the carbs pushed through. I later learnt that they changed the radius of the bonnet to avoid this!
Michael O'Leary
25/06/2012 @  23:46
RV8 Bonnet Required
Regarding factory GT V8 bonnet clearance another factor was the use of squat versions of the HiF6 carbs. For example,you have to be careful if ordering new dashpot damper pistons as the same part number can give you either the standard or the short (V8) version. I think the difference is solely in the oil reservoir neck section rather than the main body as the full dashpot lift range would be needed.
Bob Owen
26/06/2012 @  02:16
RV8 Bonnet Required
Another thought... Back in the day Clive Wheatley used to supply a bespoke engine mount kit comprising of a thick rubber mount and a thin rubber mount. I know a number of folk that used a pair of the thin mounts on V8 conversion projects to drop the height of the engine a little? Obviously, you need to anchor the engine properly with one of Clive’s steady bars to stop the RH header clouting the steering shaft when you press the "loud" pedal due to the tighter tollerances between the header and the steering shaft.
JC Moulds
26/06/2012 @  04:46
RV8 Bonnet Required
John, the low-rider air filter is exactly as you describe it ie: the base drops down around the carb almost completely covering it. Also, I am relieved to say that BMH confirmed they will make another "limited" batch (typically only about 5) RV8 bonnets which will be available around end of July.
Pat Boghossian
26/06/2012 @  07:46
RV8 Bonnet Required
I have an Edelbrock set-up and have no problems with clearance under a standard bonnet. RPi reckon that the Weber/Edelbrock is superior to the Holley in a number of ways, see:
I have no personal experience of the Holley, just passing on what RPi say.
Chris Hunt Cooke
27/06/2012 @  20:05
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