Heat Riser with fuel injected carb conversion (1 Viewer)

[ukboneman]

Hi folks, I am rebuilding my '73 F engine and going to the Holly Sniper EFI kit from Mosley, and a DUI dizzy. The original heat riser on the exhaust manifold was rusty and frozen, but I did manage to find a manifold pair that had a good heat riser. The question I have is, now that I am going to EFI, am I not better off without a heat riser. The EFI kit has a sensor on the exhaust, and I would imagine that if the riser is closed on a cold day, it might give the computer bad info on what's going on above. Also, the air resistance from the riser, while small, might affect performance. I live in Maine and it's freekin cold, but that shouldn't matter with the EFI. Am I wrong?

 

[Steamer]

Good question. My heat riser works quite well and never gave it a thought. I’m thinking the heat riser just gets the intake warmer faster, but I believe once the engine is warmed up, the intake manifold is going to end up the same temp either with a functioning riser or if it’s blocked off. I’d guess that with the O2 and temp sensors, the Sniper has it covered either way. But that’s a guess.