Installing a Weiand 177 Supercharger

Discussion in 'Superchargers, Turbos, Nitrous' started by Thunderbolt, May 6, 2019.

  1. Thunderbolt

    Thunderbolt Well-Known Member

    Im installing a Weiand 177 blower on Chevy 350 engine, its in our -67 Impala SS.
    I have used E85 N.A. about 8 years, and will continue to use it with the Supercharger, its a Quick Fuel E85 650DP carb, i have a QF E85 750DP also, bought used, that i will maybe rebuild if i feel the need to run a larger carb.
    Keep in mind i live in Sweden, so parts and knowledge are not so common, even though Sweden is the Country i Europe with the most American cars.

    I have one issue right now, is it ok that the blower drive pulleys dont align perfect, its 0.08" off, the blower pulley is "deeper" than the crank pulley. Could i maybe just shim the blower pulleys out? Or is this not an issue?
    Its a 10 rib belt.


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    Last edited by a moderator: May 6, 2019
  2. Grumpy

    Grumpy The Grumpy Grease Monkey mechanical engineer. Staff Member

  3. Loves302Chevy

    Loves302Chevy "One test is worth a thousand expert opinions."

  4. Maniacmechanic1

    Maniacmechanic1 solid fixture here in the forum

    The stock Chevy Valve spring oil shields are known to fail crack.
    Pontiac used them also on the low po street engines and they do fail also.
    Keep the RPMS down till you make valvespring upgrades or Aftermarket heads are used.
  5. Thunderbolt

    Thunderbolt Well-Known Member

    Good point about the oil shields, never heard of that before, WOT shifts are around 5500 rpm, not so high i think?
    I looked at the casting numbers on the heads and it was 462, they were rebuilt a couple of years ago, wish i had made a valve spring upgrade then.
  6. Maniacmechanic1

    Maniacmechanic1 solid fixture here in the forum

    Should Be Ok.
    Super charger Boost and Turbo Boost places much higher loads on Valvesprings all parts.
  7. Grumpy

    Grumpy The Grumpy Grease Monkey mechanical engineer. Staff Member

  8. Unforgiven

    Unforgiven solid fixture here in the forum

    yes , it is best to shim the pulley out (like grumpy states). That blower is going to want no restrictions as far as air flow is concerned. You may find that your 750cfm would be a better match rather than the 650cfm. My 383 sbc has a 177 blower on top and i found that for my application a predator carb worked the best. the predator is a variable carb that delivers cfm from 390-930. For my new motor I am using a custom built 950 cfm Pro Systems E-85 carb.
  9. Thunderbolt

    Thunderbolt Well-Known Member

    The vacuum modulator on the TH350, i have read that connected both before and after the blower can work with low boost, Weiand suggests before the blower, can i hurt the transmission if i try the after blower version?
    I have also read about some kind of one way valves on the vacuum line, some like it, some dont, any suggestions about that?
  10. Maniacmechanic1

    Maniacmechanic1 solid fixture here in the forum

    Those 1-way check valves were used on the EGR Smog system of all GM cars and trucks 1975-81 I recall.
    May work for your needs to protect the TH350 Vacuum modulator from blower boost.
    I recall seeing special Vacuum modulator cans for TH350 and TH400 for blower and Turbo applications from Ebay Sellers.
    Think Transgo company makes them.

    Racing the Vacuum modulator system is eliminated and TH350 & 400 converted to full manual shift.
    Some layouts allow the Coast overrun clutch to remain and function like stock to slow the car down yet from engine compression off the gas pedal.
  11. Unforgiven

    Unforgiven solid fixture here in the forum

    I'm not sure about hurting the trans but I have the same blower and the Vac line is connected after the blower. The trans shifts softer ( not too horrible) at lower speeds but it slams the shifts under boost. I run a th400

    I would have to look tonight but I think I run the red stripe modulator also.
  12. Thunderbolt

    Thunderbolt Well-Known Member

    Its up and running blown, but at as expected tweeks and tuning are required :)

    The vacuum modulator, under carb vacuum makes mid throttle (low boost) shifts real soft, will fry the transmission, adjusted the modulator to firmest and its accepteble but stays in first a tad too long when driving slow.

    Under blower, firm shifting but never shifts up att more than around 60-75% throttle, hits the rev limiter.
    Tried adjusting the modulator, no success.

    Falls flat in third gear, i guess fuel starvation, need co driver to read the AFR gauge and fuel pressure to verify or move the gauges up to windscreen. If i was running gas i would have already killed it with detonation :eek: but E85 is forgiving, to a point...

    Plan on mount a second electric fuel pump near the tank to feed the mechanical Carter M6900 pump as a band aid, like: or
    they are "pull through" so i can run with electric pump off.
    I have only a 5/16 fuel line, but upgrade to 1/2 line will have to be next winter, we have a short season to drive and its on.

    Timing, locked out 33 degres, (run 40 without blower) to much or to little....? E85 and 8.7:1, maybe 6psi boost (yes move boost gauge to windscreen also so i can watch it at wot)

    Wheel hop is a problem from a stand still, shakes so bad it rocked the transmission out of gear once :mad:
    Engine and transmission mounts are polyurethane. Stock rear suspension, except monroe air shocks, because we tow a trailer/caravan/camper, whats the word in american english?
  13. Maniacmechanic1

    Maniacmechanic1 solid fixture here in the forum

    Avoid wheel hop for now all it does is break driveline parts.
    If this is an coil spring rear suspension they make No Hop upper control arms and racing control arms adjustable. Its expensive at $400-600 USD.
    A low cost way is to use Truck camper airbags inside of the rear coil springs. Works for cars to 12 second ET 1/4 mile fast.
    Can use homemade traction bars also with coil springs...the floor pan is the bump stop How Arnie Beswick did it.

    I like having a fuel pressure gauge to see at all times at the windshield base or inside the drivers cockpit.
    Tells no lies if you watch it.

    Really think you should convert the Turbo 350 to full manual shift.
    Or use a Turbo 400 trans with a Transgo 400 Pro shift kit set to full manual. It will be way stronger than the Turbo 350 for low cost to build yourself.
  14. Unforgiven

    Unforgiven solid fixture here in the forum

    If this is a cruiser.. I would not lock out the timing. 33* is a safe number. All in by 3000 rpm. I had good luck with 21 initial and modified my HEI to have 12* advance.... Left the vac can un plugged. This gave me a total of 33* But... I only operate at stop and full throttle so...
    Remember... when under boost, you actually want less timing.
    This is what I will be using.

    Wheel hop can be controlled by ladder bars with a shackle on the front of bar or a slide system, so your axle won't bind. I would also look into new link bar bushings if they are originals.

    You said your compression is at 8.7:1 ? E-85 loves high compression..

    Yes you need to upgrade that fuel line to 1/2" ...

    Th400 is the better choice.. but I understand that you have a th350, I also started with one. I can't add to what you have already said you have done.
    Hopefully someone else can.

    There is a guy named Jake from Jakes Performance website who is a trans guy with alot of info. You may want to check him out.
    He answered a few questions I had when I rebuilt my th350 about 5-6 years ago.
  15. Thunderbolt

    Thunderbolt Well-Known Member

    Another question, this type of Hilborn scoop, the very small air filter must be real bad for airflow?
    I use a 14 x 3" air filter now.
  16. Unforgiven

    Unforgiven solid fixture here in the forum

    If it is an oil coated filter ..yes
    A paper filter will always flow better. K&N makes a great filter.
    Those scoops are cool, But In my opinion, a 2-3" stack installed on top of the carb, with a tall (or double 3") 14" round filter
    that is sealed from the engine bay would be a better way to go. It will aid in straightening the air before going through the carb.
    Air pressure in that scoop might affect jetting also.
  17. Thunderbolt

    Thunderbolt Well-Known Member

    You say a paper filter flows better than the cotton-oil type K&N?
    The Hilborn scoop filter is only 6.3 x 2.5"

    My deep recessed 14 x 3" filter is just over the hood now, air cleaner base look like this
    Not sure what you mean by "2-3" stack"?
  18. Maniacmechanic1

    Maniacmechanic1 solid fixture here in the forum

    A K&N 14.000" x 3.000" ( 70 TA air filter specs) tall air filter flows 930 cfm through it when I used the K&N race math off their website.
    Its in the Tech section there.
    I don't trust paper filters no more. Burn & unless you see smoke & open the hood going to loose the car with paper air filters.
    Take a K&N anyday.

    The Holley Dominator 16.000" diameter by 4 -5 inch tall aircleaner flows the most.
    Buy the base and lid from Moroso Racing parts.
  19. Unforgiven

    Unforgiven solid fixture here in the forum

    Now this is just my opinion, but yes I think an oil soaked element has more restriction than a paper element. I could be wrong...

    That is the same filter base I use.
    I tacked a piece of stove pipe in the center of that plate , then siliconed two filters on top of each other so they would clear the top of the pipe.
    Kinda like a velocity stack, inside of the filters.
    I feel that it straightens the air before it gets to the carb.
  20. Maniacmechanic1

    Maniacmechanic1 solid fixture here in the forum

    David Vizzard tested air filters. K&N came out #1.
    Recall Moroso brand filter #2.
    Max air flow in.

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