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Exhaust header
- Thread starter sky
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Pete Haburt
Senior Member
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Sky;
This depends on how you intend to drive the car. When doing these modifications, you need to take a holistic view of everything that effects breathing and flow. While the porting/polishing will improve flow, if you are keeping the same exhaust system, carbs, cam etc I don't know that a header in itself will add much to the performance. It may be more noisy, and being bolted with the intake, header flanges must be the same thickness, or you'll have to be shimming to get the mounting bolts to pull up correctly. For street driving, IMHO, the stock cast exhaust manifolds are not much of a hindrence to flow.These are torquey motors in stock trim. For track,a header with an entirely different free flow exhaust system would be better, as well as weber carbs.
Even with everything else left stock, you may find you'll need to enrichen the mixture a little due to the improved flow from the porting. If an uprated cam has been installed, you may have to replace the carb needles one richer.
Good Luck!
Pete Haburt
61 3000Mk1
This depends on how you intend to drive the car. When doing these modifications, you need to take a holistic view of everything that effects breathing and flow. While the porting/polishing will improve flow, if you are keeping the same exhaust system, carbs, cam etc I don't know that a header in itself will add much to the performance. It may be more noisy, and being bolted with the intake, header flanges must be the same thickness, or you'll have to be shimming to get the mounting bolts to pull up correctly. For street driving, IMHO, the stock cast exhaust manifolds are not much of a hindrence to flow.These are torquey motors in stock trim. For track,a header with an entirely different free flow exhaust system would be better, as well as weber carbs.
Even with everything else left stock, you may find you'll need to enrichen the mixture a little due to the improved flow from the porting. If an uprated cam has been installed, you may have to replace the carb needles one richer.
Good Luck!
Pete Haburt
61 3000Mk1
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Dear Pete,
I'm new to this as well. You may get two replies or one has gone to places unknown. Thanks for the info on the header. I think I'll stay with the stock manifold. I sent a number of parts to Medina Motors near Cleveland. I had a low lead conversion done to the head along with porting, polishing and milling, about 30 thou (I think) to up the compression. The cam was reground (a mild regrind) and the flywheel lightened. I hope this gives the car a bit more Pizazz. I'll check into getting different needles for the carbs.
Thank you,
Sky
I'm new to this as well. You may get two replies or one has gone to places unknown. Thanks for the info on the header. I think I'll stay with the stock manifold. I sent a number of parts to Medina Motors near Cleveland. I had a low lead conversion done to the head along with porting, polishing and milling, about 30 thou (I think) to up the compression. The cam was reground (a mild regrind) and the flywheel lightened. I hope this gives the car a bit more Pizazz. I'll check into getting different needles for the carbs.
Thank you,
Sky
Offline
Sky,
It is very possible that a header will help performance. These cars have larger than optimum intake systems as they come from the factory & somewhat smaller than optimum exhaust systems. The additional exhaust flow would help balance the intake & exhaust systems. The porting you did will give increased exhaust flow if the exhaust capacity is increased with a header & full flow exhaust.
It might be somewhat easier to install the exhaust before the car is put together.
Go for it!
D
It is very possible that a header will help performance. These cars have larger than optimum intake systems as they come from the factory & somewhat smaller than optimum exhaust systems. The additional exhaust flow would help balance the intake & exhaust systems. The porting you did will give increased exhaust flow if the exhaust capacity is increased with a header & full flow exhaust.
It might be somewhat easier to install the exhaust before the car is put together.
Go for it!
D
Dear Dave,
You mentioned a free flow exhaust system. I was considering the monza free flow exhaust system advertized in Victoria British for a 64 3000. It has less mufflers and less bends than a system for a 67 BJ8. Would this be suitable or were you talking about a custom built system?
Thank you
Sky
You mentioned a free flow exhaust system. I was considering the monza free flow exhaust system advertized in Victoria British for a 64 3000. It has less mufflers and less bends than a system for a 67 BJ8. Would this be suitable or were you talking about a custom built system?
Thank you
Sky
Offline
Sky,
I have no idea how well the Monza system would fit your car. It would be the earlier style exhaust. Might work well - might not fit without a lot of cutting & welding. You could contact Monza & ask them. Probably do an internet search to find contact info.
What I had in mind is more like the Denis Welch - UK parts. I was thinking of their CEXS 120 header & CEXS 127 exhaust. Go here for their catalog
https://www.bighealey.co.uk/dwm%20home%20page.htm
I have bought quite a bit of stuff from DW. They are very easy to do business with, delivery is quick, & prices quite reasonable, even with shipping costs added. Multiply UK pounds by 1.58 to get US dollars.
Maybe someone else has some ideas. By the way, there is a very good Healey list, go here & follow the directions to sign up for the Healey list.
https://www.team.net/cgi-bin/majorcool
This list also has very good searchable archives.If you don't want to sign up go here & do a search for whatever you are looking for. You can also scan through a months worth of posts at a time if you wish.
https://www.team.net/archive/healeys
D
I have no idea how well the Monza system would fit your car. It would be the earlier style exhaust. Might work well - might not fit without a lot of cutting & welding. You could contact Monza & ask them. Probably do an internet search to find contact info.
What I had in mind is more like the Denis Welch - UK parts. I was thinking of their CEXS 120 header & CEXS 127 exhaust. Go here for their catalog
https://www.bighealey.co.uk/dwm%20home%20page.htm
I have bought quite a bit of stuff from DW. They are very easy to do business with, delivery is quick, & prices quite reasonable, even with shipping costs added. Multiply UK pounds by 1.58 to get US dollars.
Maybe someone else has some ideas. By the way, there is a very good Healey list, go here & follow the directions to sign up for the Healey list.
https://www.team.net/cgi-bin/majorcool
This list also has very good searchable archives.If you don't want to sign up go here & do a search for whatever you are looking for. You can also scan through a months worth of posts at a time if you wish.
https://www.team.net/archive/healeys
D
Sky
If you're looking to the UK. Do try Classic Choice, they have a wonderful manifold and exhaust system for 3000's and they are cheaper than DW.
Classic Choice was formed from several ex SC Parts employees so they know Healey's inside out.
(I have no connection with this Company).
Regards
Alan
If you're looking to the UK. Do try Classic Choice, they have a wonderful manifold and exhaust system for 3000's and they are cheaper than DW.
Classic Choice was formed from several ex SC Parts employees so they know Healey's inside out.
(I have no connection with this Company).
Regards
Alan
Offline
Sky,
Here is a link for several UK suppliers.
https://www.austin-healey-club.com/index.html?=links.html
D
Here is a link for several UK suppliers.
https://www.austin-healey-club.com/index.html?=links.html
D