Exhaust: Please confirm no heat riser on this 289 V8

[medium_jon]

I've never seen one of the Studebaker heat risers, or what my parts book labels a `Valve Assembly Heater`, in person. But I'm pretty sure these photos of the passenger side exhaust manifold flange show one of the aftermarket spacers instead. Can anyone confirm this for me?

My truck, a 3E40, was last used regularly 25 years ago in Texas. So I'm not surprised that it has been removed. But I'm about to install a Holley Sniper 2 Electric Fuel Injection unit on one of DEEPNHOCK's milled intake manifolds and I need to make sure the heat risor isn't there as part of that conversion process.

Jon

[StudeRich]

Yes there is no heat riser in that rusted up mess, just a thin spacer, too thin to be a heat Riser Valve.
You could improve cooling of the F.I. Unit with a Intake Manifold Center Port to Head, block-off plate on each side.

[medium_jon]

Thanks for confirming StudeRich. And you’re right, it’s rusty!

I’ve got DEEPNHOCK’s stainless steel plate to put under the intake manifold gasket to block off those exhaust inlets into the manifold. That’s what you meant, right?

[StudeRich]

Exactly Jon, that will help even though not needed nearly as much without a Carb.
By the way Medium Jon, YOU should fit really good in that short legroom "C" Cab, Lol !

[JoeHall]

I probably oughta try blocking off the heat riser passage in the intake manifold of our two GTs, both if which have HFI. Maybe just do one, and see how it works out before doing the second car. I can't see any harm, but it would likely reduce under hood temps in the summer, which is always a good thing.

[wcarroll@outrageous.net]

You want to reduce as much heat as possible when you do these conversions, so block off the crossover ports for sure.

Fortunately the stock intake manifold is already an Air Gap style which helps.

If you are running an aluminum manifold, even better.

Some people also reduce overall operating temp with thermostats and better radiators, fans, etc.

But mainly it’s best to get the heat out of the intake if you want good performance.

[JoeHall]

You want to reduce as much heat as possible when you do these conversions, so block off the crossover ports for sure.

Fortunately the stock intake manifold is already an Air Gap style which helps.

If you are running an aluminum manifold, even better.

Some people also reduce overall operating temp with thermostats and better radiators, fans, etc.

But mainly it’s best to get the heat out of the intake if you want good performance.

Agree in general, but would only block off the manifold in a Stude motor that has EFI, not with a carbed motor. Been there - done that with a 56J motor (easy to block off the heat riser passage by tapping a 1/5" freeze plug into the round hole on each end). With automatic choke, the choke would open prematurely, as it took the intake manifold a bit longer to heat up enough to make the carb run right. I probably coulda adjusted the choke to delay opening, but didn't like the idea. Besides, 20 miles down the road, in summer, the manifold would still be hot enough to cause heat soak, and resultant prolonged cranking during hot restarts. As for aluminum manifold, I'd love to get my hands on one.

As for heat related problems, after 700,000+ Studebaker miles I have about conquered it: humongous radiator (equivalent of 5-row, if Stude had ever made one), HD fan (7-blade 1970s-80s GM) with HD thematic clutch and, most helpful, EFI. I have had EFI in the 62GT since 2012, and 2013 in the 63GT, so quite familiar with the mid 1980s - mid 1990s EFI technology, which mine are built from. I run 195 stats year round in the two EFI'd GT Hawks, and 180 in the 56J.

[wcarroll@outrageous.net]

Yes, I was only talking about blocking the crossover and reducing the heat when you convert from carb.