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H8Monday

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Exhaust Question
« on: April 14, 2014, 06:53:21 PM »
New member here, I've lurked for a while and there is some real knowlegable and talented folks here.
So here's my question. I'm building a new engine. A 521 Ford. Budget constraints forces me to continue using log style manifolds. The manifolds that I have are the stock Hardin Marine 'long bolt' style manifolds. I also have a set of the Glenwood short bolt manifolds available to me. I'm curious if anyone knows which  one of these 2 turds performs better than the other. The Glenwoods have a larger outlet.

Regards,   -Todd-
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GT Jets

  • Karma: +192/-0
Re: Exhaust Question
« Reply #1 on: April 14, 2014, 08:15:22 PM »
New member here, I've lurked for a while and there is some real knowlegable and talented folks here.
So here's my question. I'm building a new engine. A 521 Ford. Budget constraints forces me to continue using log style manifolds. The manifolds that I have are the stock Hardin Marine 'long bolt' style manifolds. I also have a set of the Glenwood short bolt manifolds available to me. I'm curious if anyone knows which  one of these 2 turds performs better than the other. The Glenwoods have a larger outlet.

Regards,   -Todd-


Hands down, go with the long bolts... The runners are straighter and are the most desired manifolds as far as logs go.

I am pretty sure you get more responses in favor of the long bolts... 

GT
  • Boat #1: 1992 Carrera 20.5 Elite (I/O bitches)
  • Boat #2: 19' Bubble deck Jet BBC Berkeley
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If i get some free time tonight at work, ill play with it and post it for everyone to see.

Time to man up and yank it John!  :banghead:
Ray

jet fever

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Re: Exhaust Question
« Reply #2 on: April 25, 2014, 06:31:13 PM »
I dont know about a ford but they are different angle and length on a BBC also.  My buddy had to invest in the tubes exiting through the trans also when he made the same switch.  His Hardins were worn thin in spots so he got new Glenwoods
  • Boat #1: 76 Hallett Bubble Deck
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Your Mom

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Re: Exhaust Question
« Reply #3 on: April 25, 2014, 06:57:15 PM »
Its Harman not Hardin... Harman marine long bolt are the best BBF logs period. All the others including hardin are flange type and will warp/leak at ports. The Harmans are jacketed all the way around port and have best bite...a felpro gasket can be used with them as well. Do your snails have the step down? If so, you can cut that off to get 3 1/2 out. If your tips are 3 1/2 perfect fit and if 4 add a small piece of 3 1/2 on the snail then 4 across.

GT Jets

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Re: Exhaust Question
« Reply #4 on: April 26, 2014, 10:51:08 AM »
Its Harman not Hardin... Harman marine long bolt are the best BBF logs period. All the others including hardin are flange type and will warp/leak at ports. The Harmans are jacketed all the way around port and have best bite...a felpro gasket can be used with them as well. Do your snails have the step down? If so, you can cut that off to get 3 1/2 out. If your tips are 3 1/2 perfect fit and if 4 add a small piece of 3 1/2 on the snail then 4 across.

You are correct on the name... However, if they are true long bolts, they are jacketed to the flanges. Meaning that they would be superior to any short bolt log.
  • Boat #1: 1992 Carrera 20.5 Elite (I/O bitches)
  • Boat #2: 19' Bubble deck Jet BBC Berkeley
  • Like
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    Love
    HaHa
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    Sad
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If i get some free time tonight at work, ill play with it and post it for everyone to see.

Time to man up and yank it John!  :banghead:
Ray

 


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