[bigman348]

I want to add a supercharger to my sbc 350 next summer. I was wondering how many of you guys have done it and what i need to consider before i do it. And any tips would be great. I was leaning torwards a procharger style supercharger and not a manifold type blower. Is that a good idea? I just want to make sure i make the right decision considering the money and work that is involved.
Thanks in advance

Matt

 

[cuztomcarbuilder]

Blow To Go

Talk to the people who make the supercharger...LISTEN to them... FOLLOW DIRECTIONS....Don't cut corners!!!! Buy everything that they suggest and install them as directed and have fun!

 

[pro70z28]

I want to add a supercharger to my sbc 350 next summer. I was wondering how many of you guys have done it and what i need to consider before i do it. And any tips would be great. I was leaning torwards a procharger style supercharger and not a manifold type blower. Is that a good idea? I just want to make sure i make the right decision considering the money and work that is involved.
Thanks in advance

Matt

2 bolt mains o.k. up to about 7 lbs. boost. Over that 4 bolt. O rings over 12 lbs. Steel crank with less than 10/10 grind. Stock rods are o.k. to a point 8 to 10 lbs. of boost. Make sure they are in good condition. Forged pistons 7 to 8 to 1 compression. 3 angle valve job is a good idea. I like aluminum heads for heat dissipation that comes with forced air induction. Cam is important and would be determined by how you plan to use the vehicle. Something in the neighborhood of 110 degree lob center is a good overall cam generally speaking. A good ignition system like MSD that will retard the timing under boost A good cooling system and a big free flowing exhaust system. Depending on how wild you go, you may need to beef up the trans, rear end and suspension.

 

[camaroman7d]

What are your goals for this car/engine? If you want to make some serious power, you really have to have the bottom end setup for a blower.

Forged pistons, forged crank, good rods with great bolts. I would suggest a four bolt main as well (unless you plan on keeping the boost down to the 4lbs range).

With a centrif style blower you should keep your compression in the 8- 8.5:1 range (some guys run it a little higher). You will want a cam with a LSA (lobe seperation angle) of 112-114.

You do not need to "O" ring the heads or block "IF" you run Cometic MLS head gaskets. There are guys running 18-20lbs of boost on them. I am running 12lbs with my roots style blower and Cometic head gaskets.

You will want a good free flowing exhaust, and a good cooling system (you don't need anything special, just a good solid cooling system).

I really suggest you pick up a few books and read up on how blowers work and how to make the most of them. There is far more to it than I can type here.

Royce

 

[pro70z28]

Camaroman7d

Nice lookin' Camaro. I'm building a 70 z-28 R/S Split bumper. I've got a looooong way to go tho, good to see one on the street. Do you have any problems with police and the blower obstruction? That's my biggest concern, but I recently saw & talked to a local guy with a 70 Chevelle, blown and he's had no problems, so I feel better. He even got stopped once for speeding and nothing was said about the blower.
:thumbup:

 

[camaroman7d]

pro70z28, Thanks for the compliment. I have never once been hasseled about the blower. I have had cops pull up and look the car over and say "nice car". Technically it is illegal due to the obstructed view. It has been my experience that as long as you don't get a bad reputation (by speeding, street racing, burn outs) they will typically leave you alone. Once you are a marked man (or car) they will hassle you everytime you leave the house. I have driven it all over California and in parts of Nevada, never a single problem.

I took a look at your project, looks real good, keep up the good work..

Royce

 

[HemmiGremmie]

Procharger types are just fine. Its all in what looks you want. The procharger is under the hood, while a roots is visual. I prefer the looks, but everyones different. HG

 

[bigman348]

I don't want to go crazy with racing or anything like that. I just want the power there when i want to use it or when an import wants to get stupid. I have a four bolt main and a forged scat crank. I have stock rods and am not sure about the compression. I have flat top pistons with 69 fulie heads that are 62cc i beleive. If i went supercharged i would get alluminum heads with bigger chambers. Does a supercharger mean you need a lot more fuel? and if so does that mean a lot more fuel pressure? For those who have done this how much money am i looking at realistically to do it right?

Thanks again,
Matt

 

[camaroman7d]

Whenever you make more power you need more fuel, for lower levels of boost any decent fuel system will be fine. You do not need more pressure just a steady supply. You NEVER want to go lean while running a blower, this will kill your engine in a hurry. With 64cc heads and flat tops (depending on your deck height) your compression will be in the 10:1 range this is too high for a supercharger. You will need to pull the heads measure how far in the hole your pistons are and then you can figure out what size chambers you need to get your compression where you want it.

To do it right you are looking at $8,000 - 12,000 if your bottom end is good and you can get the compression you want with the pistons you have you may be able to save a little. Also depends on how much of the work you are going to do yourself.

If you just want a little extra power every now and then you will save a lot of time and money by installing a nitrous kit on your current engine. Then you can save up some cash and build an engine just for a blower.

There is a great book out there that will give you plenty of info and cover all the basics it's called Street Supercharging by SA Designs. It will not cover everything and some things hve changed since the book was written.

Your crank and rods (if you have good bolts in the rods) are fine but, you MUST have forged pistons (you didn't say if you did or not).

You can bolt a supercharger to any engine and make some power, if you want it to live and get the most out of it, certain things have to be done. It is cheaper to do it right in the begining rather than do it wrong once and then have to do it right the second time.

Royce

 

[pro70z28]

I don't want to go crazy with racing or anything like that. I just want the power there when i want to use it or when an import wants to get stupid. I have a four bolt main and a forged scat crank. I have stock rods and am not sure about the compression. I have flat top pistons with 69 fulie heads that are 62cc i beleive. If i went supercharged i would get alluminum heads with bigger chambers. Does a supercharger mean you need a lot more fuel? and if so does that mean a lot more fuel pressure? For those who have done this how much money am i looking at realistically to do it right?

Thanks again,
Matt

Sounds like your bottom end is strong enough for some mild boost, is it a relatively fresh engine?
It shouldn't take all that much more fuel, just the drag of turning a belt. Now if you stand on it and make boost that's a different story, but yer not supposed to do that on the street anyway ....... right???? :nono:

 

[bigman348]

Well thank you everyone. I really appreciate the info. I would plan on doing all of the work myself. It is my profession and my hobby. i have hypertunic speed pro pistons. The engine only has about 400 miles on it. A nitrous kit sounds like a good idea. Do you have any recomendations? Thanks again everyone!

Matt

 

[pro70z28]

Well thank you everyone. I really appreciate the info. I would plan on doing all of the work myself. It is my profession and my hobby. i have hypertunic speed pro pistons. The engine only has about 400 miles on it. A nitrous kit sounds like a good idea. Do you have any recomendations? Thanks again everyone!

Matt

Whatever brand you choose my preference would be a "wet Kit" (one that uses an extra - separate fuel system to feed extra fuel to the engine in conjunction with the nitrous). Less chance of encountering a lean condition under power. Lean is bad ......... very bad. :sweat:

 

[camaroman7d]

Matt,
Pick the brand of your choice but you need to keep the HP level to no more than 100HP with hyperutectic pistons. Those pistons are decent for mild applications, the problem comes in if you start trying to push the limits. Hyper. pistons do NOT tolerate detonation very well and are very sensitive to ring butting. I know people that have run 125HP shot of nitrous on them and got away with it but, that was on race gas.

A simple plate nitrous system will do what you want. It will inject/mix fuel and nitrous. There are certain "safety" features you will want; a full throttle switch (so it only comes on when you are to the floor), low fuel pressure cutoff (disarms the system if your fuel pressure drops), For a 100 HP shot you dont "have" to have a dedicated fuel system for the nitrous. If you can swing it I would HIGHLY recommend it anyway. Going lean with nitrous is like taking a cutting torch to your pistons. If you don't get greedy and keep it at 100Hp and follow the above suggestions you should be fine. You will also have to retard your timing a few degrees with on the bottle, this can be done via a dash mounted timing retard knob or you can adjust it with a timing light when you plan to squeeze.

You can be up and running for about $500 (including full throttle switch $30 and fuel pressure safety switch $36), add a little more if you decide to run a seperate fuel system for the nitrous (electric fuel pump, filter, fuel line, relay, switch). The seperate fuel system is not a must for a 100HP shot, just an additional safety feature but, if you run the pressure safety switch there is really no danger, cause if the fuel pressure drops the nitrous system will be dis-armed.


Royce

 

[pro70z28]

Royce
Have you tried a small nitrous shot on the blower as a way to cool the intake charge? I'm told it works. I've also been told it should be injected as close to the heads as possible although above the blower would be easier. I've converted an Enderle injection hat to E.F.I. and have the old mechanical injection holes in the hat. That would be a good place for the nozzles, but I don't know if that's a safe place to install it. Not saying that I will at all, but it's a thought.

Injection hat (no use for mechanical injection holes)

 

[pro70z28]

well that didn't work so goooode'
I'll try that attachment again.

I've also kicked around water injection for the same "arrest the denotation" reason.

 

[bigman348]

Thanks again for everything. Do i have to run higher pressure with nitrous? Becuase right now i have a GM high performance pump and it puts out 11 p.s.i i have it regulated to about 5. (by the way what is desireable for just my car as is whit no supercharger or nitrous?) I would definetly get the switches you were speaking of. Thanks agian. You guys have been great.

Matt

 

[camaroman7d]

pro70z28, No I have not tried nitrous with my blower and don't plan to right now. This thing makes PLENTY of power. I went with an 8-71 so I could spin it slower and make more boost without the heat. Yes, I have seen cars with nitrous and blowers and I have seen it plumbed exactly where you are talking on yout injection hat. I have also seen direct port nitrous injection. All the research I have done says that roots blowers love nitrous. Once I get bored with the power I have I may give it a shot, I just don't know about all the solenoids and lines, those along with the blower and carbs might get a little cluttered looking. With injection that wouldn't be a problem. Hummmm maybe I will have to go injected and add nitrous. See what you started? LOL

Matt,
Your fuel pressure should be set somwhere between 5-7psi naturally aspirated. You will still want to run about the same fuel pressure with a blower or nitrous, you just need a pump that can keep up. The pump you have may be just fine for nitrous. As long as it can keep a constant 7psi even when on the bottle it's fine.

Royce

 

[Siggy_Freud]

Also be sure to bump back the timing a few degrees. Read about N02 use and play it safe. Most engine failures with N02 are a result of ignorance.

 

[pro70z28]

pro70z28, No I have not tried nitrous with my blower and don't plan to right now. This thing makes PLENTY of power. I went with an 8-71 so I could spin it slower and make more boost without the heat. Yes, I have seen cars with nitrous and blowers and I have seen it plumbed exactly where you are talking on yout injection hat. I have also seen direct port nitrous injection. All the research I have done says that roots blowers love nitrous. Once I get bored with the power I have I may give it a shot, I just don't know about all the solenoids and lines, those along with the blower and carbs might get a little cluttered looking. With injection that wouldn't be a problem. Hummmm maybe I will have to go injected and add nitrous. See what you started? LOL

Royce

I went with the 1071 on the big block for the same reason. This is my first go around with forced induction, so I'm learning what I can. I've got a long way to go with the car, so hopefully when I'm ready for power I'll be half way educated on the subject.

The EFI conversion is supposed to be the hot setup for the street. Very dependable and very responsive. ................ very expensive too.:smash:

BTW: The injection hat is a lower profile than the carb/air cleaner/scoop combo too.

 

[camaroman7d]

pro70z28,

I have played with nitrous in the past and I am not a big fan of it. Only because when things go wrong it gets ugly in a hurry. If I were in your shoes I would run the blower and see if you even want/need the extra HP from nitrous. If you build your engine right I don't think you will need the nitrous. You are in for some serious torque and unreal throttle response. You made a smart choice by going with the larger blower too.

As far as injection goes, I work on/with computers for a living so the last thing I feel like doing when I am out burning rubber is flipping open the laptop and tuning. EFI can be a challenge to get set up but, once it's right the efficiency is hard to beat. I may just change my tune when I get tired of 3-5 MPG around town and 12 on the highway. Won't take long to pay for that injection with the fuel savings alone.


Royce