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Old 06-23-2016, 03:20 PM   #1
davepl
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Heat Riser concern

I'm a little worried about my heat riser on my stock 402 because it stays closed mostly at idle.

It's still spring loaded and operates freely. But at hot idle it's still forcing a lot of the heat through the manifold crossover, and most of the exhaust flow comes out the driver's side pipe only.

How normal is is that?

I also have some overheating at idle issues and I wonder if its not aggravating that a little bit.

My question is how important is the heat crossover in the summer time? Could I just wire it open or would I lose driveability during the warmup phase?
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Old 06-23-2016, 04:23 PM   #2
mike16
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Re: Heat Riser concern

remove the parts and put them in a ziplock bag and put them in the glove box. block off your cross over and install a manual choke.
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Old 06-23-2016, 04:44 PM   #3
davepl
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Re: Heat Riser concern

Quote:
Originally Posted by mike16 View Post
remove the parts and put them in a ziplock bag and put them in the glove box. block off your cross over and install a manual choke.
Yeah, no, I'd like to stay stock. I grew up with two-foot vehicles with crappy cold driveability and no interest to repeat it in middle age.

I expect: pump twice, turn key, start, run, drive. No exceptions, no two-foot, no bogs. Worked in 1970, should work today.
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Old 06-23-2016, 05:20 PM   #4
dennislbrooks
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Re: Heat Riser concern

I do not run a heat riser on my 402. It warms very quickly by nature. And I run a quadrajet. But I also do not do winter driving where it might be beneficial. I say wire it open and see if any difference to you.

There are various discussions on this forum and others tossing it back in forth. Here's just one.


http://www.chevytalk.org/fusionbb/sh...php?tid/12837/

Also mine in summer in gear at a stop will creep up in hot weather --- maybe about 200 but I am not sure we need to worry about it either if the radiator does not puke. My 85 vette does not turn on the fans until 236 unless ac is on---- same stop sign witha manual and it will climb to 215.

Gauges make us crazy sometimes. The 442 455 auto and I do run a heat riser on it. It just has an idiot light and as long as it is not on --I feel good.
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Last edited by dennislbrooks; 06-23-2016 at 05:29 PM. Reason: words
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