MG Sports Cars

engine swaps and other performance upgrades, plus "factory" and Costello V8s

Go to Thread: PreviousNext
Go to: Forum ListMessage ListNew TopicLog In


Jay1973
John Clark

(2 posts)

Registered:
03/11/2022 08:32PM

Main British Car:


Rover v8 conversion bonnet clearance
Posted by: Jay1973
Date: March 11, 2022 08:44PM

Hi,

The shop doing my rover v8 conversion is having problems with bonnet clearance. The car is running fuel injection and the plenum has been cut down but as far as I can see only the base. View seems to be that the top of the plenum canít be reduced as it is sitting very close to the top of the rocker covers. If we move the engine lower on its mounts , the exhaust manifolds foul the steering rod - we are using Clive Wheatley RV8 style manifolds which run through the inner wings. Any thoughts on this appreciated as trying to avoid fitting an RV8 bonnet.



Edited 1 time(s). Last edit at 03/15/2022 09:57AM by MGBV8.


MGB567
Barrie Braxton

(38 posts)

Registered:
04/26/2015 12:13AM

Main British Car:


Re: Rover v8 conversion bonnet clearance
Posted by: MGB567
Date: March 15, 2022 03:56AM

I too had issues despite using Glenn's mounts and shaving as much as possible off the plenum base - I have not lowered the plenum as you need some clearance for the trumpets.; actually my 45mm trumpets are trimmed quite low as I ensured my runners were of equal volume. I originally had the rectangular plenum but I changed that for the curved version which is slightly lower at the front (and rear but that doesn't matter). Have you tried it with removing the x brace on the B's bonnet? Not only have I done that but I've remodelled my steel bonnet to a C look alike as I prefer that to the other B bonnet options including the RV8. I have sufficient clearance now. All my mods are detailed on MGE's Darkside



Edited 3 time(s). Last edit at 03/15/2022 09:58AM by MGBV8.


Jay1973
John Clark

(2 posts)

Registered:
03/11/2022 08:32PM

Main British Car:


Re: Rover v8 conversion bonnet clearance
Posted by: Jay1973
Date: March 18, 2022 12:47AM

Thanks. Have the same plenum as you and it does not seem to be catching on the brace. Really reluctant to go for another bonnet but seems may have no choice.


Justinb
Justin Broome

(26 posts)

Registered:
06/10/2009 12:33PM

Main British Car:


Re: Rover v8 conversion bonnet clearance
Posted by: Justinb
Date: March 18, 2022 01:44PM

How much did you shave off of the trumpet stack? Should be around .750" and even then it's a super tight fit, depending on your motor mounts.


mstemp
Mike Stemp
Calgary, Canada
(219 posts)

Registered:
11/25/2009 07:18AM

Main British Car:
1980 MGB Rover 4.6L

Re: Rover v8 conversion bonnet clearance
Posted by: mstemp
Date: March 18, 2022 03:32PM

Can't recall the exact amount but you need to remove from Bottom side of the trumpet stack, then 3 to 5mm from the top side of it. Also, then a few passes on the underside of the plenum cover. I missed the top side of trumpet stack and with D&D Fabrication motor mounts, it just kisses the underside of the bonnet after a hard drive. I also have Clive Wheatley steady bar to limit rocking of motor.


Sorry, only registered users may post in this forum.