Dart Pro 1 heads and Patriot clippster headers leaking - help

Mustang Australia

Author Topic: Dart Pro 1 heads and Patriot clippster headers leaking - help  (Read 1871 times)

Offline SMH00N

  • Thoroughbred
  • **
  • Posts: 150
  • Location: Sydney
  • Name: Stephen
  • Car: 70 Sportsroof Grabber pac
People

I'm at the end of my rope here. I have a 302 with Dart Pro 1 alloy heads that have been slightly ported. Using Patriot H8420 'clippster' shorty headers.

On first install, all was good. But, after about 100 miles the kerb side rear (either #7 or 8) started leaking.

I have done nearly everything I can to rectify it; multi layer gaskets, fitting 2 gaskets, cutting the mount flange to allow them to move independently, milling the mount faces, screwing them on with nearly a breaker bar. There's no tension in the system, headers are bolted up then exhaust pipe bolted on, the system was fabricated from the headers back when the headers were bolted on.

Is this a common issue? The offside set are fine as are the 2 front cylinders on the kerb side. I am thinking it is the headers and not the heads, due to the fact that no other port is leaking.

Any new set I put on are going to cost a shiite load and I'd prefer not to waste money just trying stuff.

Offline pmb0186

  • Thoroughbred
  • **
  • Posts: 142
  • I'm new here
  • Location: adelaide
  • Name: PETE
  • Car: 66 MUSTANG
I had a similar problem on my corvette kept blowing out gaskets.
Fit a copper gasket and retighten after a week and been good ever since. Good thing about copper is you can retighten multiple times
does anyone remember laughter

Offline SMH00N

  • Thoroughbred
  • **
  • Posts: 150
  • Location: Sydney
  • Name: Stephen
  • Car: 70 Sportsroof Grabber pac
1970 LHD 302 header recommendations
« Reply #2 on: July 07, 2023, 12:58:53 pm »
I have tried all I can with these and they still leak. No copper gasket seems to be readily available for the large ports.
Has any one used any header brand apart from FPA that fit in a manual steer LHD 302? When I say fit, no denting, cutting or grinding.

FPA is probably my fix but the $2,000 cost is going to hurt.

Offline AussiePhil

  • Worked
  • ***
  • Posts: 786
  • Location: Bathurst, NSW
  • Name: Phil
  • Car: 68 Coupe
Hey,
Are your heads 200 thou. oversized ports, if so have you tried Felpro 1262R inlet manifold gaskets.
Cheers Phil.

Sorry

 :lmao:
« Last Edit: July 07, 2023, 05:35:05 pm by AussiePhil »
If you've never buggered anything you've never done anything!
But if you've buggered a lot maybe you're not very good at it!

Two for one is good but four for two is better!

Offline SMH00N

  • Thoroughbred
  • **
  • Posts: 150
  • Location: Sydney
  • Name: Stephen
  • Car: 70 Sportsroof Grabber pac
Re: Dart Pro 1 heads and Patriot clippster headers leaking - help
« Reply #4 on: July 07, 2023, 03:58:41 pm »
Inlet manifold gaskets will fix the exhaust manifold leak? Really?

Offline AussiePhil

  • Worked
  • ***
  • Posts: 786
  • Location: Bathurst, NSW
  • Name: Phil
  • Car: 68 Coupe
Hey Stephen,
Don’t know what I was thinking, I was rushing out the door and thought I’d sent a quick reply!
Sorry for the dickhead mistake!
I’ve got stock standard felpro steel / fibre gaskets, and no problems!
Are you forcing the rest of the exhaust on that could be reacting to an angle misalignment, I have exhaust bell fittings not flanges!
Cheers Phil.
If you've never buggered anything you've never done anything!
But if you've buggered a lot maybe you're not very good at it!

Two for one is good but four for two is better!

Offline SMH00N

  • Thoroughbred
  • **
  • Posts: 150
  • Location: Sydney
  • Name: Stephen
  • Car: 70 Sportsroof Grabber pac
Re: Dart Pro 1 heads and Patriot clippster headers leaking - help
« Reply #6 on: July 20, 2023, 01:07:14 pm »
So an update and a warning to potential buyers - Petronox advise these headers will not fit the Dart heads, presumably due to the port size.
If anybody wants a slightly used set of ceramic coated headers for standard heads, I'll have a set for sale at the end of September :)