6-71 Blower Surge

[GT63]

Finally got my 6-71 installed and the engine running. I'll post photos later. It idles good and starts right up, but how do I get rid of the blower surge or do I want to? It seems to like the timing around 16 degrees.

thanks

 

[RPM]

Mine surges till it warms up good. I have 18 deg timing in mine and idles about 900 rpm. Of course that could be different depending on what cam, carbs, and heads.

How much boost will it make?

 

[Lee_in_KC]

Grant, what are your carb and ignition set-ups?

 

[GT63]

OK, here's the scoop. It's a 350 SBC bored .030 over. It's a 010 block with 4 bolt mains using ARP studs. The crank is forged steel. The Rods are GM performance LT1 rods that have been pinked(sp). The pistons and rings are a match set of Keith Black forged blower pistons with -18cc dish. The heads are Edelbrock performer RPM aluminim heads with 70cc chambers, 2.021.60 ss valves, and roller rockers from Crane. The cam is a Comp Cams 268AH-14 with a 114 lobe center. The blower is a NEW 6-71 from The Blower Shop. The top pulley is a 59 and the bottom is a 48. It uses an 8MM belt. The carbs are those new BG Road Demon Jr inline blower carbs with 625CFM. Ignition is MSD 6al and MSD billet distributor with a Mallory coil. I'm using a Holley Red electric fuel pump.

Here's a link to my Picaso gallery.
http://picasaweb.google.com/gtolbert63/Blower_installed

I had to do alot of trail and error to get the fuel line plumbed since the fuel ports are on the driver's side.

Took it for a test drive. It doesn't surge when it's Drive, and it almost dies if I rap the throttle real hard and let off. My Weiand 142 I replaced did this too.

 

[Lee_in_KC]

Well, I don't know those carbs at all. I just have dirt-simple Edelbrock 1405s. The most believable explanation of blower surge I have heard is that the blower sucks the idle circuits dry so the motor starts to unwind, then the idle circuits re-charge and the motor spins back up, then the blower sucks the idle circuits dry again and the cycle just repeats itself. I can tune the blower surge out of mine with the idle screws, but I kinda like it, so I leave it in.

 

[MDANIELSON55]

yo grant i adjusted everyway i knew to simmer my 8/71 down and finally i did find the whomp was the ideling of the carbs. the linkage wasnt set egual so i had the motor idleing on one carb and slowly introduced the front carb until it made motor increase rpm then set linkage back 1/4 turn. all fuel air and bowls were set before i adjusted the linkage this way mike

 

[GT63]

Thanks Guys, I haven't played with the carbs yet. It took me several weekends to get the Wieand 142 I replaced figured out, so I figure this will take me a little while as well.

http://picasaweb.google.com/gtolbert63/Blower_installed

 

[RPM]

2 words say it all "Very nice" :lol:

 

[chuckt]

Looks great GT. Anxious to hear how it runs compared to the 142.
I have a Weiand 177 on mine and I like it

 

[GT63]

Looks great GT. Anxious to hear how it runs compared to the 142.
I have a Weiand 177 on mine and I like it

With the 142 on this motor , it made 341HP at the rear wheels on a chassis dyno at 5700 RPM. The AF/R was off a little bit. I changed the jets in the edelbrock carb and never got back over to the dyno before I made this upgrade. Properly tuned with this combo, it should get close to 400HP or more. Which is more than enough for the street.

 

[LumenAl]

Man that just looks bitchin! Sweet!

 

[VegasBruce]

Awesome ride GT

 

[Lowrollerchevy]

6-71 and weed burners ... now thats the way to do it !

wow ... freaking wow

 

[Rick]

With the 142 on this motor , it made 341HP at the rear wheels on a chassis dyno at 5700 RPM. The AF/R was off a little bit. I changed the jets in the edelbrock carb and never got back over to the dyno before I made this upgrade. Properly tuned with this combo, it should get close to 400HP or more. Which is more than enough for the street.

Ive got a 351 W in mine and have been looking for a blower for mine forever do you still have your old one?And if so how much yes i know i would need a new intake.

 

[pete rallis]

if it almost dies at idle, or revs up and down at idle, its too lean. on an injected motor, you just fatten the barrel valve up, but on a carbed motor, you have to richen the idle circuits, or buy carbs set up for a blower.

 

[GT63]

if it almost dies at idle, or revs up and down at idle, its too lean. on an injected motor, you just fatten the barrel valve up, but on a carbed motor, you have to richen the idle circuits, or buy carbs set up for a blower.

These are BG Road Demon JR Inline Blower Carbs. They come as a set and are set-up for a blower. I'm gonna play with the idle mixture settings this weekend to see if I can get the blower lope (surge) out as best I can.

 

[GT63]

Ive got a 351 W in mine and have been looking for a blower for mine forever do you still have your old one?And if so how much yes i know i would need a new intake.

If I sell it, it will be a package deal. intake, Wieand 142 blower, Edelbrock 800 CFM carb, scoop, pulleys, belts, fuel pressure gauge, boostvacuum gauge, and the carb tuning kit. I've got two other fellas that have asked as well. I'll post it on the "For Sale" forum if I decide to sell it.

 

[T-Odd]

I know how to get rid of that blower surge. Take it off and sent it to me LOL.

Did you have the problem with the little blower you had on it? I don't recall ever hearing any surging from that old setup you had.

I've never heard a big blower that didn't surge but that doesn't mean you can't mellow it out a little bit.

Got a video of it?

 

[GT63]

Well I got most of the blower surge out of it.

Here's a little video

6-71 and zoomies on a T-bucket

 

[GT63]

Here's a link to some newer pictures

Picasa Web Albums - Grant - 05172008-tbucket