I have a Weiand 142 on a ZZ4 crate motor, no intercooler which is how it came from the previous owner. Looking at Weiand 142 installations on YouTube I don't find one with an intercooler.

What's the determining factor as to when/whether you need one?

 

You do not need one unless you are trying to push its ability. And in that case it has to be placed between it and the intake. Which i suspect would be more $$ then any gains you might get

 

How much boost pressure are you pushing? The higher the boost, the higher the S/C heats the air. Very high intake air heat can cause premature ejac detonation.

Any intercooler on a Roots blower will need to be sandwiched between the blower upper assy and the lower assy., which will increase it's overall height, which will require either a big block/custom hood, or cutting a hole in your hood.

If you are running somewhere near 5 - 7 pounds of pressure - No worries......

 

6 lbs. Sounds like it's just not needed on a mild setup like mine.

Since posting my question I read that the air-fuel flow on a carb'd setup also has a cooling effect.

 

That it does.

OT question for you - Is the build date on your 'Vette close to your Birth Date. That would be cool......

 

14 pounds boost no worries

 

Nice. I thought I had problems with hood clearance - I guess at a certain point you have to just ditch the hood altogether - lol.

 

Intercooler gives you a lower IAC which allows more timing then equals more power! I have a liquid to air intercooler sandwiched between my Kenne Bell blower on my 4.0 in my Jeep, it's over kill for the 6lbs I'm currently running, but I can get away with the timing in hot humid Louisiana summers safely.

 

The act of compressing air creates heat. The more boost the more heat. More heat into the charge and then the piston compresses it even more, the more chance of detonation. If you have enough octane, the heat will be less of an issue. So it's a balancing act. If you have too much heat and cylinder pressure, and not enough octane, then you will have detonation. If you're pushing the limits, then you should consider changing the balance. That could be lower boost or E85 or alcohol or lower charge temps (intercooling) or higher octane or less timing . There are other factors like swirl and combustion chamber shape as well and cold air into the pump, spark plug temp and more. Modern engines have knock sensors to determine of you're close to the edge and reduce timing if knock is present.

My gut feel is that 6lbs on 93 octane may be ok in most cases. 14lb on pump gas is risky without intercooling IMHO. Not saying it can't be done, but I wouldn't. Also 14psi for a short blast is not the same as 14PSI on a quarter mile.

 

I run 100 octane and 32 degrees of timing .

 

I’d bet that if you had an IAT sensor measurement, the intake air charge is still pretty hot. My last car was turbocharged. It allowed me to use any intercooler I chose. Additionally, I had a stand-alone water/meth injection system from Sno-cooler that sprayed blue windshield washer fluid into the intake air stream. In the case of the OP, an intercooler isn’t a viable option, but the water meth is. A 1 gallon reservoir, rarely got low enough to worry about. ( I kept it checked, and besides, the system came with a low level warning light anyway).
WW fluid is cheap, and in every parts store, and gas station. The benefits to using it are two fold, not only will it cool the intake air charge, but the meth mixture effectively increases the octane, which reduces chances of detonation. As long as you have an air cleaner mounted on the carb, so that it could be misted into the space above the carb, you have a way to inject it.
There may be kit manufacturers making a base plate injection kit like a nitrous plate as well.

Whether or not 6 pounds of boost makes it a required mod, there is significant evidence of the torque gains that come from using a kit like this on a roots type blower. I can’t say if it’d help that much at 6 psi, but it certainly wouldn’t hurt.
https://www.lxforums.com/threads/met...76765/?u=31470

 

Compression makes heat. But a turbo charger with the exhaust right next to the intake fan makes more heat. That’s when the intercooler is necessary. It’s also easier to plumb because the turbo is not sitting right on top of the intake. It’s much less of an issue with the roots type blower. Not saying it’s not necessary but if you’re running a 142 it’s not like you’re doubling your intake charge.

 

Thanks. I'm probably pushing my luck as it is with a blower on a stock ZZ4 with powdered metal rods and hypereut pistons, trying to squeeze more oomph out of it might have unintended consequences.

 

just remember the first half of the word blower is also used in blow up...

 

That's the point I was making. You've changed the balance by running higher octane. I would have stated that right away.

 

I will also suggest that you look into the Water/Methanol injection systems as they were designed for just that application. During WW2 the Luftwaffe used the water/methanol injection to give their engine a temporary boost in power while pushing them hard at the same time. Eventually the USAF started using it on their high compression and turbo/supercharged engines.

I am not using any type of Turbo or Supercharger but still have an application where the water/methanol injection system really helps the engine. I have a L88 Replica engine running the 12.25-1 Compression ratio and most of the year it works without any help but the Water/methanol injection can save your engine. The extra water is used in the combustion cycle and helps pull heat out of the combustion chamber as it converts to steam and the methanol hives your fuel a serious boost in octane. It is able to make 93 Octane into 116 octane which slows down the burn time and prevents detonation.

The injection system works great and in the end replaces the need for any kind of special fuels. It even works better than the Aviation 100 Octane Low lead gas I tried for a while. With the leaded fuel I started seeing lead building up on the crowns of the pistons. Using the water/methanol injection system the combustion chamber stays nice and clean and the controller only activates it when under a load.

There are several companies making the water/methanol injection systems and most are for turbo or super charged vehicles where there is no room or money left for an inter-cooler.

 

I used to play a little with a 85 Buick Grand National (that was the year before the factory installed an inter cooler) and it would handle 15 to 16 psi of boost with 93 octane pretty darn good , factory preset was around 6 to 7 pounds before the threaded rod adjustment so it woke it up pretty good and the 1985 still had a knock sensor so you try to stay safe from that kicking in and losing the power you just gained from the computer retarding the timing

 

There really isn't much heat transfer between the housings. If there was it would be easier and cheaper to cool the center housing than putting an expensive and delicate intercooler in the mix.

Intercooling/aftercooling isn't to compensate for other conditions. Its about increasing air density to pack a greater mass of oxygen into the cylinder so you can burn more fuel to make more power. The goal isn't pressure, it's air mass.

 

Right. The term "Blown" applies in either case.

 

Better air density is a good side effect. However, the major role of the intercooler is to reduce the charge temperature. Without the intercooler, you've got an already hot charge of air, somewhere around 250F for 15psi, that now gets compressed even more by the piston. The hotter the charge before the piston gets to it, the hotter it's going to be once the piston compresses it even more. Too hot a mass of air and fuel under pressure and you have detonation. Say goodby to your pistons.