My Small Block Chevy Swap

[brinker88]

First page of my build thread. I netted right around 2.5" lift with them. They settled about had an inch tho.

 

[RockLobster01]

After a run to the parts store, the outside tunnel ram temperature (engine is at 190 degrees)

Note: RPM range before this reading was not above 3,500.

 

[alwaysFlOoReD]

So what's your theory for what's happening? Is it beneficial to engine operation/power?

Richard

 

[RockLobster01]

@Richard

"Really this is just a more exotic version of an single plane. All the intake runners are straight and meet at a common plenum (the tunnel). This type of manifold gives excellent fuel distribution and flow for top-end power. The large plenum area reduces signal strength and throttle response, so it takes some good tuning to make these responsive for street driving.
When tuning in one of these, you'll need a quick accelerator pump and more ignition timing down low. In most cases, you can lock your distributor to total advance. You might need a retard box to retard the timing while you start it, but for the most part tunnel rams run best with a lot of advance at an idle. If you want an advance curve on a street tunnel ram set up, use a vacuum advance and hook it directly to manifold vacuum. The poor mixture at low rpm requires a lot of timing at idle and cruise conditions.
Many people will argue that tunnel rams are a race only, high rpm manifold, but this is not really the case. They have worked very well on street engines and when tuned right will almost always out perform a single plane manifold across the rpm
range. I have seen many back-to-back dyno pulls where a tunnel ram beat single plane manifolds."

Taken from this article on induction systems. I highly recommend reading this by the way

http://www.stealth316.com/misc/grapeape-inductionsystems.pdf

 

[alwaysFlOoReD]

I'm talking about the heat loss on the spacer, where is the heat going? To my mind it's going directly into the engine. Which usually, from a power standpoint, isn't a good idea. Edit; tho it can be good for efficiency. It's been a long time since I've looked into carbed systems so don't remember what happens with such a large plenum, how it affects distribution, power, idle, etc. I'm just wondering if you could explain it. If you can explain it, then you have researched it. If it did what you thought it would, kudos. I think it looks alright, but if it does nothing for power or efficiency, in my books it's usefulness is over.
I hope you don't take what I'm saying as dising you, because I'm not. I think it's great that you're trying out new ideas.
Keep it up,

Richard

 

[RockLobster01]

Sorry it's been a while guys, lots going on here.

@Richard: basically the more air/fuel mix you can cram into the engine, the better. (Keep in mind I'm still tuning). As for the heat loss, it's basically like an air conditioner works.

Taken from PerformanceBoats.com:

"This is normal for a tunnel ram and good carb working together. When air expands it cools. You have a lot of velocity through the venturis, and it expands into the tunnel ram making the air cool very rapidly.The cooling of the tunnel ram is from the evaopization effect of the fuel removing heat from the air in the low pressure of the intake. The cooling effect means your carb and tunnel ram are atomizing the fuel very well, giving you a denser charge, which is definitely a good thing."

 

[dangerranger83]

Been watching this build and have to say good job. That's one hell of a radiator you have in front but it's what you had to work with. My v8 swap was the same way, I worked with what I had and what I could find for the right price but also would do the job correctly. A lot of people seem to be question what you are doing and all I can say is answer them the best you can but they are also giving some good advice to and I would stay away from it either.

Just remember, it's your truck, do as you please to it no matter if they like it or not.

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