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MG MGB GT V8 Factory Originals Technical - Position of holes for exaust

Where would I find a template or diagram for where the holes need to be cut for headers to exit thru the fenders? Any ideas would be appreciated since it seems that there would only be one shot at this. Thanks so much, Clint
C.E. Jackson

depends what motor & where you set it up.
x Ficalora

I guess that would be some valuable info to relay also. I'm putting in a 3.5 using D&D motor mounts and I'm going to use the automatic trans that came with the engine. I understand that having the exaust exit thru the fenders will aid in cooling and eliminate some clearance issues. Thanks
C.E. Jackson

You can contact D&D. www.aluminumv8.com. They have the templates for the RV8 exhaust to use with the positioning of the motor mounts that they sell.
Tom

It'll also depend on the make of headers you've got, and will be different on the left and right sides. If they are the asymentrical kind You might also decide to reverse them to get as close to the front crossmember and as far from the tyres as possible. you'll need to shift your brake lines if thats the case, and if that is legal. Also you will want to see if an exhaust pipe ends up in some inconventient place ie obstructs an oil drain or contacts a hydrolic hose. It really is one of those fit it and see messy sort of jobs.
I fitted the engine then fitted the down pipes by line of sight. Presumably your engine is currently out of the car which is why you are asking. You could try useing your engine mounts as the reference point. Their location will be common to both engine and body. On the engine measure back to the downpipe. Then that distance back from the mount on the body. The holes end up very close to the rail. About an inch at the closest. Since the rail is a big stiff metal beam this doesn't matter. If you go slightly too big, this just aids cooling the engine compartment. I have never had a problem with mud or water splashing up through the hole. The amount of air going out prevents this.
Peter

Clint,
Like Peter says, you really have to have the engine in place, and your headers in hand, so to speak. There's not really any hard and fast guide to locate the openings otherwise. With the motor in, mark and cut bit by bit, using the loose header to guide you. I'd say make the openings big enough so can can pull the engine with the headers attached. Later, finish the edges. Many builders put a crescent shaped removable piece over the top area, secured with stainless hardware, to dress it up and keep the openings tidy. Best, Joe
Joe Ullman


I did it the way Joe recommends, but i'm not happy with the results. The hole required to install the motor with the headers attached is bigger than it needs to be. And i did it with just the motor -- with the tranny attached, I'd need to make the holes even bigger to allow for the tilting that has to be done to get the motor & tranny back in. So, i'm reworking that area on my car (i was fortunate enough to have a rusted out body shell with good inner wings so I'm using them to close up the holes). This time I'm leaving just enough extra space around the headers so i can set them in the holes & tilt them out when the motor is being intstalled or removed. I'll probably still use the crescent covers (see Robert Milks' car for a good example... http://www.britishv8.org/MG/RobertMilks.htm) but the holes will be smaller & cleaner than if you make them big enough to pull the motor with the headers attached... If you're using motor mounts & headers from the same place, a template would be a great thing!
x Ficalora

Keep in mind that large holes there will aid tremenously in cooling. With the rail at the bottom and the very complex guard and upper region of the engine compartment; it's very strong and a bit cut out above the rail will not effect the strength even remotely.
I saw one car where the owner had fitted flat polished stainless shields directly above the extractors. These piggy backed onto two of the extractor (upper) bolts. He had glued some insulating material under the stainless. There were cutaways for sparkplug access.
It really looked very good, aside from the obsuring of the guard holes and extractors. Of course he has no cooling problems at all.
Peter

This thread was discussed between 30/09/2006 and 03/10/2006

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