Rootsy
04-08-2004, 11:51 PM
I received my GLM Aluminum exhaust manifolds from dennis moore today (thanks Dennis). The following is an initial visual assessment from an engineers standpoint. With any luck we'll have quantitative numbers from a performance standpoint later in the year.... as i stated previously i am looking for donors for other manifold systems to test...
1st assessment.. DAMN this box is light where is the OTHER manifold.. oh weight there are 2 in here... 31.50 lbs total shipping weight from fedex ground... I LIKE THIS :)
2nd assessment... visually very nice from the outside.. a bit of porosity here and there but as long as there are no leaks externally or internally.. no biggie... a lot of new plugs vs stock merc that is for sure all plugged in brass except for one... and what is this extra straight thread tapped hole into the exhaust port??? So Dennis what is this hole for? it is roughly a 3/4 straight thread of well i donno what pitch yet... O2 sensors are 18 mm x 1.5 thread...
Internal assessment... significant runner seperation when compared to other aftermarket exhaust manifolds. I've seen GLM, Stock Merc, GIL, SM and IMCO... this has by far the most runner seperation EXCEPT for the GIL's which is the most individualized runner manifold i have seen. Runner inlet dimensions are 1.45 high x 1.4 wide (average of 4)... the exhaust manifold to riser opening is 2.0 wide x 2.5 long which yields 5 sq inches... compared to other true round aftermarkets which average 2.75 - 3 inch round diameter or 5.9 - 7.1 sq inches... Runners are quite rough with some flash just in from the exhaust port entrances. With a lost foam process this should not be a real issue to control... but easily cleaned up with a die grinder and sanding roll... no biggie... there appears to be some form of core shift in a fwe of the runners though... this kind of threw me since a lost foam and lost wax precess doesnt generally suffer from this... still.. easily cleaned up... otherwise everything looks pretty tidy inside.
Overall impression - for 119.95 each.. a good deal when compared to other aftermarket manifolds... 139.95 for powdercoated manifolds.. still a good deal... Risers are extra and IMCO M-72 risers can be purchased for about 650 new.
From an engineering standpoint it would make sense to modify this manifold possibly for use with other aftermarket exhaust riers such as the IMCO Powerflow. By removing the side water passages and routing to the front and rear a elliptical to round opening could be configured to match the IMCO or similar risers. Passing the water through the front side of the manifolds instead of the side would accomplish adequate cooling. Further, if the manifold was a dry seal there are plenty of water passages plugged to allow for water routing from manifold to riser via transfer hose. with todays CAD, CAM and Casting processes this is entirely feasible while retaining low cost...
Attached are photos of the GLM SBC Aluminum exhaust manifold... more photos when i can ACTUALLY get them to attach properly... but this should give you a meat and potatos of the internals... the important parts ;)
Enjoy
JR
1st assessment.. DAMN this box is light where is the OTHER manifold.. oh weight there are 2 in here... 31.50 lbs total shipping weight from fedex ground... I LIKE THIS :)
2nd assessment... visually very nice from the outside.. a bit of porosity here and there but as long as there are no leaks externally or internally.. no biggie... a lot of new plugs vs stock merc that is for sure all plugged in brass except for one... and what is this extra straight thread tapped hole into the exhaust port??? So Dennis what is this hole for? it is roughly a 3/4 straight thread of well i donno what pitch yet... O2 sensors are 18 mm x 1.5 thread...
Internal assessment... significant runner seperation when compared to other aftermarket exhaust manifolds. I've seen GLM, Stock Merc, GIL, SM and IMCO... this has by far the most runner seperation EXCEPT for the GIL's which is the most individualized runner manifold i have seen. Runner inlet dimensions are 1.45 high x 1.4 wide (average of 4)... the exhaust manifold to riser opening is 2.0 wide x 2.5 long which yields 5 sq inches... compared to other true round aftermarkets which average 2.75 - 3 inch round diameter or 5.9 - 7.1 sq inches... Runners are quite rough with some flash just in from the exhaust port entrances. With a lost foam process this should not be a real issue to control... but easily cleaned up with a die grinder and sanding roll... no biggie... there appears to be some form of core shift in a fwe of the runners though... this kind of threw me since a lost foam and lost wax precess doesnt generally suffer from this... still.. easily cleaned up... otherwise everything looks pretty tidy inside.
Overall impression - for 119.95 each.. a good deal when compared to other aftermarket manifolds... 139.95 for powdercoated manifolds.. still a good deal... Risers are extra and IMCO M-72 risers can be purchased for about 650 new.
From an engineering standpoint it would make sense to modify this manifold possibly for use with other aftermarket exhaust riers such as the IMCO Powerflow. By removing the side water passages and routing to the front and rear a elliptical to round opening could be configured to match the IMCO or similar risers. Passing the water through the front side of the manifolds instead of the side would accomplish adequate cooling. Further, if the manifold was a dry seal there are plenty of water passages plugged to allow for water routing from manifold to riser via transfer hose. with todays CAD, CAM and Casting processes this is entirely feasible while retaining low cost...
Attached are photos of the GLM SBC Aluminum exhaust manifold... more photos when i can ACTUALLY get them to attach properly... but this should give you a meat and potatos of the internals... the important parts ;)
Enjoy
JR