setting up distributor springs and spacers on b/b stroker?

[3rdelke]

as my son and I close in on his gtx clone, we have had his motor running, but will be improving his upper valve train with roller rockers. also gonna swap out his ignition with msd 6al box, and a 8546 dist. wondering which springs and spacers to start with. I think his specs are as follows. 477 stroker, iron heads 11.5 to 1 ross flat top pistons, comp cam .545 lift, dur 241 247. dual quad with 2 750 afbs on a stock cast iron manifold. hemi 4 speed, mini tub, 410 dana. thanks....bob and kevin

 

[Burns69RT]

The two light silver springs, that way you'll be all in at 2400rpm and as for bushings the dizzy the smallest msd comes with is 18* but a company FBO or 4secondsflat.com sells bushings for the msd dizzys they're a 10* and 14* bushing. I would do the 10* bushing. That will allow more advance on the crankshaft.

 

[hunt2elk]

Call Don at FBO. He will have what you need.

 

[coloradodave]

You might want to try the set-up as it comes out of the box. 11.5:1 compression with iron heads on pump gas is going to be a challenge. As delivered, the MSD #8546 distributor has the blue 21* advance bushing installed with 2- silver springs. This gives you 21* mechanical advance , all in at about 4,000 RPM. Using about 15* initial advance at idle, you'll have a total of 36*.
If you don't experience any pinging on acceleration under load, replace one of the silver springs with the next lightest one (blue), which will get your advance in at about 3,600 RPM. You can keep changing springs until you get pinging and then go back to the last pair that didn't ping. One advantage of the MSD is that bushing and spring changes can be made without removing the unit from the engine (unless you have sausage fingers...lol).
With that compression, I doubt whether you will be able to run more than 14-16* initial and still get no pinging and easy hot starting.
Good luck and let us know what works for you.

 

[Burns69RT]

You want to be all in at around 2400rpm. And personally as well most of everyone here agree. Less mechanical advance and more initial advance. Even with that compression. 10* bushing for mechanical and 28* on initial timing. I've never had problems and 440's love that, strokers even more.

 

[3rdelke]

guys, thanks, cant wait to get new rockers, and start tuning. do most guys here do their own tuning, or do you take it to the "Dyno Dude" in your area?

- - - Updated - - -

dave, my son was informed early in this build that pump gas would not work. they think the compression ratio is over 12 to 1

 

[Kern Dog]

Sounds like a race gas mill.
Sorry for the following, but......
WHY DO PEOPLE BUILD SKY HIGH COMPRESSION ENGINES FOR THE STREET ??

 

[Dennis H]

9.5:1 here. It was a dance to get it to run on 91 pump here which is the best available at common stations. High speed roll ons under certain conditions were susceptible to pinging. About 500 @ the crank.

 

[3rdelke]

Kern Dog, thanks for typing that where I can read it. don't think I mentioned it being a street car

 

[Burns69RT]

Snow performance water meth and run a high compression motor on the street running 91 octane.

 

[coloradodave]

You want to be all in at around 2400rpm. And personally as well most of everyone here agree. Less mechanical advance and more initial advance. Even with that compression. 10* bushing for mechanical and 28* on initial timing. I've never had problems and 440's love that, strokers even more.

You, of course, can do what you want. As far as real world experience with a 10:1 motor on 91 octane and iron max wedge heads, I can't run more than 16* initial, 36* total, all in at 3,000 RPM. A/F is right on the money from idle up through the RPM range. 4 speed with 3:91 gearing and 28" tall tires. Any more initial and the motor kicks back when it's hot. Bringing it in sooner will ping under load.
I've run motors with water/alcohol injection on the street with good results, but at my current age I don't have the patience to fiddle with it. I drive my car and want it to work well all the time. To each his own.
I guess I shouldn't have assumed that the original poster was talking about a street/strip car. RACE CARS ( as in, NO street time) have way different parameters ...

 

[Burns69RT]

Agreed. And for the timing I had a 10.1 440 with ported 906 heads 600 lift solid roller street monster love it mechanical timing at 10* and the initial at 28* total of 38* and all in at 2400rpms never pinged and ran the streets like a bat out of hell.

 

[3rdelke]

thanks to everyone! got the 10 degree bushing, and light springs in, all went well.

 

[383man]

Sounds like a race gas mill.
Sorry for the following, but......
WHY DO PEOPLE BUILD SKY HIGH COMPRESSION ENGINES FOR THE STREET ??

You can run pump with 11.5 comp but you better build it the right way or you wont be able to run pump as Kern Dog said. You would want to have quench and aluminum heads to start with if you are at 11.5. Its going to be tuff to run pump with 11.5 comp and iron heads. I would do as "Colorodo Dave" said and try it as it comes and then work from there. But you are not going to be able to run any agressive timing with your comp and iron heads. Good luck with it. Ron

 

[3rdelke]

ron, thanks, my son is not really concerned about the expense of some ratio of race fuel, or straight race gas if the performance is there. He gets back here in the states only twice a year, car wont be driven much unless I get bit by the street race bug. yhx, bob

 

[383man]

ron, thanks, my son is not really concerned about the expense of some ratio of race fuel, or straight race gas if the performance is there. He gets back here in the states only twice a year, car wont be driven much unless I get bit by the street race bug. yhx, bob

I ended up doing my 63 as pump gas street car that I can race if I like because I really cant afford to build a race car on my budget and this way I could put $20 bucks of gas in it on a Satuday night and go for a cruise and drive the car around. Its actually fun driving on the street as I get alot of thumbs up and alot of looks from people who just dont know what a 63 Sport Fury is. So atleast for $20 bucks or even just $10 dollars of gas I can drive my 63 when I want and enjoy it. To go racing will usually cost me atleast $100 dollars and thats even with driving it to the track. I love to race it but when cash is tight atleast I can drive and enjoy it. Ron

 

[1wild&crazyguy]

If this car has decent gears, a stick, or good convertor, you don't have to worry about too fast a curve.

You can make your own ''bushing'' out of a nut using a file and a dial back timing light to check.
The silver and blue springs work great and give full mechanical advance by 2200--2400 the last one i made in 10 min gives 8 degrees of mechanical advance.easy

 

[3rdelke]

Thanks to all you guys. after a little machining got the 10 degree bushing in, and the light springs. when I put my timing light on it where should I set it initially. thx, Bob

 

[reeltime]

My last motor 496 was spec'd by Dave Hughes engines. It was 13.4 compression ratio. Ran it 6 years 1000 street miles and I lost track of the drag passes.It injested a bolt and is in for a refresh. Needs one sleeve and one piston.Oh ya it must have aluminum heads and have a cranking compression of under 200psi. Mine was 195 psi. The cam you choose controls this. Dave did a excellent job specking this out.In the US you can buy high octane pump gas correct ? If so this engine would likely by fine. Run the timing back to 30 dregs. To start and work it up until you hear it rattling then back it off enough to stop it. Hope this helps.
I could only get 93 octane gas here in Canada so that is what it ran on.I was running without a air filter cause it ran a tenth faster that's how it ate the bolt. Great engine that made 735 hp and 700 foot lbs. torque.Good luck

 

[3rdelke]

reeltime, sounds wicked fast. thanks