supermaxxbasher

I have a low compression stock 350 and I was wondering if I can slap a weiand 142 blower on it without haveing to build the bottem end. What else is required when adding a blower to a stock engine. How much horsepower can I expect with this blower and some kind of a blower cam and ported and polished 882 heads.

supermaxxbasher

I am hoping for over 400 ponies but if it requires aftermarket heads then I guess I will put some pro action heads on it. Oh and the compression is around 8.5:1

sleepybu

if you have good oil psi, go for it

unknown_host

iTrader: (1)

If your goal is 400 horsepower, a set of vortec heads, an extreme energy 274 cam and some shim gaskets will get you to your goal without overly stressing your stock bottom end.

Damon

You'll like the blower. You can get 400HP N/A relatively easy these days but not with anything like the torque of a roots blower- and at a lot lower RPM. The 142 was originally designed to make very mild 350 making about 250HP into a 350HP motor with supplied pulleys. So it's engineering was desgned around adding about 100HP over stock on a mild 350. On my 383 I pulleyed it up and went from about 350HP (n/a) to 450HP (with blower). So 400HP is well within it's capability. Up around 500HP you'll be pretty well maxed out- it jsut can't flow enough air to get much beyond that, in my opinion.

Stay conservative with the timing- 26-28* total (excluding vacuum advance) is a good starting point. Yes, you can probably push it higher than that but the consequences of detonation in a boosted motor are SWIFT AND SEVERE. Stay conservative. And don't ever ever run lean- build a fuel system that capable of feeding well in excess of what a 400HP motor requires.

You'll like the blower. Without any change in rear gear ratio it's "tire smoke on demand" due to the big bump in torque EVERYWHRE IN THE RPM RANGE from the boost.

F-BIRD'88

A Crane HMV 278-2 is a good cam for this combo.
Crane cam specs


a friend of mine went low 12's with just such a combo.

A 750cfm carb with a little richer secondary jetting will work well.

I second the advice on conservative ignition timing and
a good fuel system.
use the best available octane gas too.
Detonation must be avoided with stock cast pistons.

supermaxxbasher

hey thanks guys I like the sound of that better.

supermaxxbasher

Ok guys time to renew this thread...My engine blew before I could get the blower...well I had to use my blower budget to rebuild it so now its time to start all over...........The engine now has 9;1 compression iwth 76cc heads which I have on there..with Hyper pistons and a 272 crane cam....I am still wanting to do the blower scene cause I think it would really kick butt...:hail: :hail: BUt should I even attempt it with the higher compression..

Damon

I was running that blower on a motor with 9.2:1 compression and hypereutectic slugs. I blew it up (ripped the ringlands off a few pistons) BUT I KNOW WHY. I had gotten "greedy" with the ignition timing. I didn't THINK I was in detonation, but obviously I was when I tore the motor down.

If you run modest boost (5 PSI or less) and keep the ignition timing conservative (28* total) and don't ever EVER run lean it will probably last a long time.

Is it even worth doing for 5 PSI? Oh yes. It'll feel like you strapped a rocket to the back of the car. HP maybe only jump by ~75 but the bottom end torque is quite amazing. Not like a nitrous hit but there's a big 'ol heaping helping of torque down there.

Plus the cool sound of the blower winding up through the gears. Unearthly noise. Unmistakable. And fun.

supermaxxbasher

hey thanks guys...I will prolly end up putting in some forged pistons for peace of mind..lol..Can someone tell me how much HP the bottem end of the motor can take...cause I am gonna try and make upwards of 400hp with this motor and I just need to know if I should replace the bottem end..thanks

flrtin1

Going with the forged pistons is the best selection imo, also try to stay away from chrome moly rings they are a harder material than the dutile iron rings and are more prone to shattering with any type of detination. Another suggestion would be to get a timing retard like MSD offers so you can stay retarded when doing just normal driving also a 6k rpm limit will go a long way with stock crank and rods. One other thing to watch is your octane level it needs to go up in colder weather becase air density on a blown motor is affected much more with cold air than on a N/A motor

EDIT: I would try to stay under 8:5.1 with the cr

Damon

Just remember that ANY piston will eventually fail under detonation. Forged slugs jsut take longer to kill. The real answer is to never encounter detonation. I'll take hyper slugs, lower compression and no detonation over forged slugs, higher compression and borderline detonation any day of the week.

8.5:1 might sound dismally low for compression but for a roots blower engine with iron heads it's not. It also won't be a "dog" down low crusing around at part throttle like you might think. Attention paid to the ignition advance curve makes a pretty big difference in my limited expereince with these motors.

flrtin1

This is from holleys tech section it is good info on what to use when you are planning on building a blower motor and why low static CR is important



Table 1 shows that you obviously can't try to run 10 pounds of boost on a 9.0:1 compression ratio engine. This gives you an effective compression ratio of 15.1:1, way beyond our 12:1 figure. If you are building your engine from scratch, it is a good idea to try to build it with a relatively low compression ratio, such as 7.5 or 8.0:1. It is fairly easy to change the boost to get the best combination of performance and power, but it is extremely difficult to change the compression ratio, especially if you want to lower it. Additionally, you will make more total power with a low compression, high boost engine than you will with a high compression, low boost engine.

(I could not get the table to paste here so go to this link and look at TABLE 1)

http://www.holley.com/HiOctn/TechSer...fo/SCTech.html

The above chart shows the effective compression ratio of your engine, which combines the static compression ratio with the amount of supercharger boost. Note that for most street applications with 92 octane pump gas, you should keep your effective compression ratio below about 12.0:1.

fbody83

882 heads suck as well, no flow. They are prone to cracking as well.

supermaxxbasher

Does anyone have a pic of this type of blower in the camaro...

flrtin1

check my web site I had the B&M 144 on my car from 1986 till 1990

unknown_host

iTrader: (1)

Whatd it run out of curiousity?

Cross R Jeff

My apologies for intruding, but i too hv a gen 3 / 95'-Z28 fxn to do a motor swap frm LT1 to LS1 or LS2 Wh like LS6 HEADS or sum...but my quest is I also hv a 94' Chevy Blazer Silverado 4x4 wh a 6" fabtech lift, & the motor don't smoke, burn oil, leak wh about 218,000 mi on orig. motor 5.7L 350 V-8...So how would that B&M142 wrk out on my truck? Overkill or badass?