[Aussie Bill]

Hi all,

This is my first post. My name is Bill and I reside in Perth, Western Australia, Australia.

My question is about the Weiand 177 blower on a SBC 350.

The combo consists of a 350ci 30 thou 3970010 4 bolt main with ARP bolts, forged 3.480 GM crank, 5.7 pink rods with ARP fasteners with SRP -12cc dished forged pistons. Heads are 76cc 487X heads inlet and exhaust runners matched to felpro gaskets, port work on bowls intake and exhaust, these have not been flowed on a bench so unsure of the flow numbers. 1.6 Lunati roller rockers guide plates and studs. Blower referenced Holley 850 cfm carb. MSD Ready to Run Distributor with multiple spark and rev limiter box set to 6200rpm (conservative).

Car weighs 2205 pounds with 3.55 ratios on 14 inch rims.

Have the pulleys to make 7-8 PSI on 92 Octane fuel (I am using american ratings for ease of understanding as our equivilent fuel is 98 Ron) supplied by a Holley Blue at 6psi.

My question is, which cam would you advise to achieve 450 hp at the rears if 450 is achievable and will s[SIZE=3][FONT=Calibri]urvive for a while[/FONT][/SIZE]?

Springs will be bought to match the cam.

Your advise would be greatly appreciated.

[F-BIRD'88]

Crane F278-2 or Crane F280-2.
Crane down under
Crane Cams Australia

[Aussie Bill]

Thanks for the reply. They appear to be mechanical cams. I am really not keen on them, prefer quite hydraulic flat tappet cams. Also the rpm is quite high 6800 rpm. Again thank you for your responce.

[vinniekq2]

got to agree with fb, flat tappet hydraulic is the last cam I would pick.
at least use a roller hydraulic

[F-BIRD'88]

Originally Posted by Aussie Bill

Thanks for the reply. They appear to be mechanical cams. I am really not keen on them, prefer quite hydraulic flat tappet cams. Also the rpm is quite high 6800 rpm. Again thank you for your responce.

These Crane flat tappet cams will not be noisey.
Set the valve lash cold,, .004" tighter than the cam card spec.
You will have a whole new opinion of solid lifter cams.

They are not noisy, at all, are the right cams for your motor and will outperform a hyd cam. Especially in a blower motor.

The rpm range will depend on how high you choose to rev it. That is what your foot is for. But yes they are capable of high rpm.
Take another look.
THESE ARE NOT NOISY CAMS.

Get a boost retard box for high boost. Either of these cams and the 2.10 or 2.33:1 drive ratio on that blower should get you there.
The F278-2 is a very street friendly cam and just right for the job and your 1.6 rockers.
It is designed for the street and street motors just like yours.
Most people don;t know how to set valve lash and most set it too loose.
You will find it easy, quick and pain free by setting the lash COLD... .004" tighter than cam card.
use the IC EO method.
When the engine is running at temp the hot lash is correct.
You will not be able to tell this solid cam from a hyd when its running. Especially compared to the fast action "extreme" hyds.

The success of this motor will depend on how good of a job you did porting the 487X heads. They need more than a pocket port job to wake them up. When done right they work well, but they need the full boogie.

Feel free to contact Crane Cams for tech advice:
www.cranecams.com

[Aussie Bill]

Thanks FB. With that drive ratio 2.10 or 2.33:1 I would presume detonation would be a concern and if I push this little blower harder higher air temp will be created therefore creating a perfect situation for detonation. Yes/No?

[F-BIRD'88]

Originally Posted by Aussie Bill

Thanks FB. With that drive ratio 2.10 or 2.33:1 I would presume detonation would be a concern and if I push this little blower harder higher air temp will be created therefore creating a perfect situation for detonation. Yes/No?

These blowers are still quite efficient at this drive speed and definatly make more power. (this is well within their working range) But yes detonation must be avoided.
You always want to sneek up on the tune.
less timing, fat jetting.
I would start testing using high 110+ octane fuel.
and sneek up on it.
The crane F278-2 will work very well. It is a tame street cam.
The engine cr should have been lower. your self imposed rev limit is too low.
re limiter is only to avoid run away rpm. Set it at 6800-7000rpm.
on pump gas you will be in the 26 to 28deg timing range under boost.
You may have to sweeten up the pump gas as required.
Race gas is cheaper than pistons.

water methanol injection is a option.

Ideally this engine should have a 7.5:1cr The actual qualtity of your "ported heads" is a unknown.
I know what I can get out of them....

i cannot tell you the limits of your pump gas there...good or bad, but to hit your power target you need to step on it a bit.
start with race gas. See the power..... Then, switch to pump gas--50-50 race gas blend tune back up as required for pump gas while paying close attention to timing and knock. A hyd or Hyd roller cam is a mistake on this motor.

[F-BIRD'88]

Are you actually going to put some sticky tires on this car and use the power?? ..or..??

quote: therefore creating a perfect situation for detonation. Yes/No?

Remember this is your engine design...not mine...
You did not spend any money on cylinder heads so put good high octane gas in the tank and give it some boost.

but....

7.5:1 for pump gas allows high boost and big power.

its just that easy and you can fix that if you want true pump gas roots supercharged power.
open the heads to 80cc chambers and remachine the piston dish to -22cc... finish max porting the heads.
Call JE Pistons for the hows and limits on modding their piston. It is probabily the same piston forging as their -26cc D dish piston. They will advise.
If you are not willing to do that put the required good gas in the tank... There is no free lunch.

[Aussie Bill]

Hi FB. No problems the engine has not been assemble yet and I can swap the psitons as they have not been installed. What dish -CC piston would you recomend to get to the 7.5:1cr. I was going to tune it myself but on second thoughts I will take it to a reputable tuner here with the gear to measure fuel etc etc. I have a "Performance Distributer" a HEI modified from your part of the world in the USA. This is a locked unit. Is this distributer just as good as any other or not that special. I will go with the F278-2. Just so you know this engine is being hooked up to a T350 with 2500 stall and its going into a BMW E30 2 door which weighs 2200 pounds. Should be interesting.

[Aussie Bill]

Originally Posted by F-BIRD'88

Are you actually going to put some sticky tires on this car and use the power?? ..or..??

Will have to otherwise this car will be like driving in the rain with bald tyres, don't get me wrong it will be fun just not practical.

As stated above in a previous post the chosen vehicle is a 1985 2 door BMW E30 @2200 pounds and 3:55 gears we are hoping low 11s or high 10s if the car does not twist its self in half. The car will be driven on the road very occasionally for ****s and giggles and blow some european cars away. People will not know what hit them.

[F-BIRD'88]

Originally Posted by Aussie Bill

Will have to otherwise this car will be like driving in the rain with bald tyres, don't get me wrong it will be fun just not practical.

As stated above in a previous post the chosen vehicle is a 1985 2 door BMW E30 @2200 pounds and 3:55 gears we are hoping low 11s or high 10s if the car does not twist its self in half. The car will be driven on the road very occasionally for ****s and giggles and blow some european cars away. People will not know what hit them.

Well when you are running it hard put race gas in it. It will out live you.
one street tires on the street you will never get to use the power on high boost
so just back off on the street boost.

track///hi boost ---race gas
street ///less boost ---pump gas.+boost retard.. just that simple.

remember -.004" set CoLd. enjoy

this should be in a little Holden shouldn't it? is that car really going to be that light weight with a 350 SBC V8 in it?

A RX7 V8 weights 2600+ its is very easy to go fast with a light car.

[F-BIRD'88]

You have a choice to get 7.5:1 on this motor. (assuming o deck height and .041 gasket.

80cc heads and -22cc piston dish

or 76cc heads and -26cc pistons.

I am prepping the same style heads (full ported 920's) for a very similar 350 blower build.
it is not hard to open these up to 80cc chamber volume. Match to the cylinder bore, not the gasket.

JE pistons can advise. low low low engine compression ratio is your friend for this...

The distributor is fine with a recurve or locked out..and a better MSD HEI coil. Get a MSD boost timing master and a MSD box
or the old stand alone universal MSD boost timing master works with HEI's etc (inductive discharge)
(out of production but you can still get them)
Use cooler Champion RV8C or equal .035" gap.

[Aussie Bill]

Cheers. I have read that when applying boost the spark can get blown out therefore a smaller gap is required.

Thanks

[F-BIRD'88]

Originally Posted by Aussie Bill

Cheers. I have read that when applying boost the spark can get blown out therefore a smaller gap is required.

Thanks

the resistance of the spark is relative to the gap size and pressure.
more gap just requires more voltage.
.035" is plenty big gap and hi voltage is a slippery slope. (tends to go the easy path)

weighs 2200 pounds. Should be interesting. thats a under statement... good luck..

[vinniekq2]

Aussie Bill,just for kicks and giggles,look up Judd V-8 BMW