Firstgens.com

I know there are a few of us out here. Let's get this power adder section rolling. Post what you have, questions, comments, etc..

First a comment..........
Royce & Mike.....your blown cars are absolutely awesome!!!! ...wish I had went that route when building my Camaro.

Now a question....are blown engines any more or less prone to detonation than my high compression naturally aspirated engine????...or is it a matter of proper parts applications in both types of engines????

David F.

David,
First thanks for the compliment.

As far as detonation, blown motors are not prone to detonation. The good thing about blowers is you can drive around all day and not make any boost. In order to make boost you have to have a demand for it. In cruise situations you will have vacuum just like a N/A engine. Since the compression of a dedicated blown engine is low 7.5 - 8.5:1 detonation is not a concern at all unless you are making boost which effectively increases the compression by stuffing more air and fule into the cylinders.

If you start overdriving the blower, then heating the intake charge can create detonation issues. If you size the blower correctly for the use of the car and engine size, this shouldn't be an issue at all. The things you have to be concerned with is static compression ratio, timing and blower speed, those are the biggest factors in causing detonation in a blown engine.

The sweet thing is you can cruise around on low octane fuel and never worry about it and when you want to hammer on it you can put some good gas in it. I build mine to run on 91 octane and I don't have any real worries about detonation even at 8.47:1 which is higher than ideal compression. 7.5 - 8.0:1 is ideal. The new engine I built is between 7.5 and 8:1.

You are only a piston and cam swap away from having a blower ready engine, you already have the other good parts. Buy a blower kit and you are set to go.

Royce,
Thanks for the detailed response!!! Looks like the next build will include a blower

David F.

David,

Royce pretty well nailed it. I was in the same boat as you,,fixing to build a 540 naturally aspired motor. But I had a buddy who had 2 blower motors. I knew nothing about blower motors/ still know very little. But I got a good deal on it. It is 9 to 1 compression and I did add the thickest copper gasket to get the compression down. I run it on 93 octane gas and have no detonation. It was defintely a learning experence. Once you have a blower motor you will not go back. Ask Royce. He has 2 of them. You have instant torque thru the power band.

One of the things to not skimp on is the cooling system. Once you start leaning out the motor for the street it starts running hotter. But when it is rich and surging it is bada$$. At least my wife thinks that.

Plus the first time you pull into a show or cruise in,,,everyone will be coming to check it out.

Thanks also Mike for your input!!! Gonna print Royce's and your reply to my question so I can refer to it when necessary!!!!!!

David F.

Mike is 100% correct once you feel the responsiveness and instant torque you will fall in love with blowers. If you pay attention to the details, you can have a very reliable high HP engine that is fairly tame until you mash the go pedal. I like mine a little on the rowdy side, surging and loud, but you can build them real mild and still make big power.

No need to print out the info, you know where to find us. I will suggest that you buy the book called Street Supercharging by SA Designs. I read that book cover to cover several times and any other blower related info I could find. I wanted a blown engine for years and I just studied up on them until I felt like I knew enough to make an attempt at building one. I could not have been happier with the result of the first one.

When you are ready to start planning your build ask lots of questions. I will answer what I can and will let you know if I don't know the answer. You will also find that there are several schools of thought on certain aspects of blown engines and on those things you can ask 5 different "experts" and get 5 different answers, that's why I studied up so I could form my own opinion on those things.

Here are a few sites you can visit to read up on some tech stuff. www.theblowershop.com www.hamptonblowers.com www.blowerdriveservice.com

Once again feel free to ask questions I can talk about this stuff all day (I am addicted). There are no silly questions either, so don't hesitate.

Always been a nitrous guy kind of by default, but I'm always willing to learn!
I actually love the blowers, nothing makes torque like a roots blower (maybe a 450 horse shot...lol). Watching the blown alcohol guys run at the track is amazing, it's not making the horsepower thats the problem with them, it's using it all!
I have actually considered a centrifugal in the next build. Untill then I'll have to just watch and learn from you huffer guys, will you let a poor nitrous guy tag along?

Sean,,,

We still like ya. You can hang with us anytime.

Sean,
You are more than welcome to tag along, I'm sure you can add/teach us all something as well. I almost went centrif on this last engine, and if all out HP is what you're after they are more efficient. They can't match the instant torque of a roots though and the look and sound of a roots is what swayed my decision. I will do a centrif at some point, but for now I can't give up the roots blower. The build of the car makes a difference too. My cars are more street than race, so all out performance is not the "main" factor. Getting the power to the ground can be challenging since it hits so hard.