Slant Six Forum
https://slantsix.org/forum/

Recurve
https://slantsix.org/forum/viewtopic.php?t=24550		 Page 1 of 1
Author:  Aggressive Ted [ Mon Aug 20, 2007 1:36 pm ]
Post subject:  Recurve
On the recurve, should I be using the light stock springs on each weight? Leaving the stock light one on one weight and adding the light spring from a V8 distributor to replace the heavy looped spring?

The looped spring on the distributor is very stocky and won't let the distributor budge past 10 degrees of mechanical at 2500. That is why I was asking if the loop could be made larger/reshaped with out breaking the wire.

Most of my driving is between 1500 and 2500 (35 to 60). If I take it on up to 4000 it just lays you in the back of the seat and I generally run out of smooth road since I am over 100 mph with the tall gears.
Author:  440_Magnum [ Mon Aug 20, 2007 2:18 pm ]
Post subject:  Re: Recurve
Quote:
On the recurve, should I be using the light stock springs on each weight? Leaving the stock light one on one weight and adding the light spring from a V8 distributor to replace the heavy looped spring?

The looped spring on the distributor is very stocky and won't let the distributor budge past 10 degrees of mechanical at 2500. That is why I was asking if the loop could be made larger/reshaped with out breaking the wire.

Most of my driving is between 1500 and 2500 (35 to 60). If I take it on up to 4000 it just lays you in the back of the seat and I generally run out of smooth road since I am over 100 mph with the tall gears.
The "looped" spring doesn't do ANYTHING at minimal advance, so if you add a second light spring in its place you'll actually reduce the amount of advance at any given RPM up to where the looped spring would have started acting. What most v8 re-curvers do is just remove the looped spring altogether and use just a single lightweight spring. Different strengths of lightweight springs are available in re-curve kits.
Author:  Aggressive Ted [ Mon Aug 20, 2007 2:29 pm ]
Post subject:  Recurve
Quote:
Different strengths of lightweight springs are available in re-curve kits.
Whose recurve kit do you recommend?

Would the Chev kits work? They have very short yellow, blue and red springs, (light, medium and heavy).

or do you know where MOPAR kits are available?

Thanks!
Author:  Aggressive Ted [ Mon Aug 20, 2007 2:56 pm ]
Post subject:  Recurve
Should I use one of these springs?

http://store.summitracing.com/egnsearch ... 0&D=316320

and replace the heavy looped spring with this one?

I have been told that using both of the ones in the kit at the same time dumps everything in by 1500 rpms.

That is too early for my situation as a street car.
Author:  Shaker223 [ Mon Aug 20, 2007 6:02 pm ]
Post subject: 
http://store.summitracing.com/partdetai ... toview=sku

I use both of these on the street and they are cheaper than the mopar springs. Full advance by 1200rpm. I've also used just the lite stock spring with good results as well.
Author:  Aggressive Ted [ Mon Aug 20, 2007 6:26 pm ]
Post subject: 
Quote:
I use both of these on the street and they are cheaper than the mopar springs. Full advance by 1200rpm. I've also used just the lite stock spring with good results as well.
Does your car have a stick? or automatic like my Swinger?
What rear end ratio?

Are you using a 15R govenor or 9R?
with stock weights?
Do your weights bounce of the ends at high rpm?
or is your high end nice and smooth?

Seems awful soon for full advance on a street driven car. What is your total advance without vacuum?

I am trying to shoot a little higher, at least 2200 to 2500 rpm to hit 30 degrees.

To get 30 degrees right now I have to run 20 degrees initial because I am only getting 10 degrees out of the mechanical. I would like to reverse those numbers to 10 initial and 20 mechanical by 2500 rpm.

Thanks,
Author:  Shaker223 [ Mon Aug 20, 2007 7:44 pm ]
Post subject: 
Quote:
Quote:
I use both of these on the street and they are cheaper than the mopar springs. Full advance by 1200rpm. I've also used just the lite stock spring with good results as well.
Does your car have a stick? or automatic like my Swinger?

Automatic

What rear end ratio?

3.23

Are you using a 15R govenor or 9R?
with stock weights?

Not sure

Do your weights bounce of the ends at high rpm?

They shouldn't with centrifical force

or is your high end nice and smooth?

Won't go past 4500

Seems awful soon for full advance on a street driven car. Never been a problem on my cars but some i don't use the vac advance. i set those at 36 total and leave it.

What is your total advance without vacuum?

16 degrees but have 20 psi of boost

I am trying to shoot a little higher, at least 2200 to 2500 rpm to hit 30 degrees.

To get 30 degrees right now I have to run 20 degrees initial because I am only getting 10 degrees out of the mechanical. I would like to reverse those numbers to 10 initial and 20 mechanical by 2500 rpm.

Thanks,
Author:  Doctor Dodge [ Tue Aug 21, 2007 9:40 pm ]
Post subject: 
So... your heavy spring must have a real small loop.

It is hard to beleive that you can run 20 degrees initial advance and not get a rough idle and / or hard restarting when hot. does the engine idle better when you pull the initial timing back to say, 12 degrees?

For your street combination with "mixed" driving conditions, stay with a "staged" spring set-up.

In general, you want to run as much initial advance while maintaining good idle quality and acceptable hot start. (8-12 degrees initial) You need to play around with this to find what is best for your combo.

A fast light spring is needed for the next 14-18 degrees of mechanical (1000 to 2400 RPM) then set the heavy spring to "catch" and slow the mechanical advance way down for the last 4-6 degrees and set that last bit of heavy advance spring timing to happen right at your freeway RPM range. (2400 to 2800 RPMs, do you have a tach?)

The total advance should be limited to appx 30 degrees total. It is best to have shorter weight - govenor slots so the heavy spring does not continue to "creep" as RPMs increase when you decide to rap the engine out)

Use a high travel, adjustable vacuum advance pod for best street perf.
This is a "ballpark" curve, all engine / vehicle combos need "fine tuning" to maximize.

Keep looking around for heavy springs, there are many different ones out there.
DD

Image
Author:  Aggressive Ted [ Wed Aug 22, 2007 7:32 am ]
Post subject: 
Doc,

Will do and thanks for the advice. I guess from what I hear you saying is that it is not a good idea to rebend the loop in the big spring, but find another one.

The car starts great, infact with quite a bang with the higher compression, never a problem when it's hot, rerouted the fuel line.
After 12 degrees there is hardly any difference in idle quality. 16 is smooth, but 20 is ok.

Yes, I have a large tach. All my driving is between 1500 and 2500 rpm (35-60 mph). However, I did take it up to 4000 a few times but ran out of smooth road. That is about 100 mph!

Yes, my big spring is short and stiff, smaller loop. No pinging because the distributor only gives me 10 degrees advance at 2500. I do have a fairly light spring the other weight.

I would like to go about 15 degrees initial and try to get about 15 degrees mechanical by 2500 rpm. If I can find a spring with a bigger looped end that isn't so stiff maybe I could get a few more degrees.

I use a 11R vacuum advance for a 360. That seems to provide another 13 degrees advance at 2500 rpm. I am thinking of filing the stops to get a little more throw out of it. It still doesn't ping at 43 total. That is 20 initial, 10 mechanical and 13 vacuum advance. I can't find any advances stamped higher than 11R.
Do you know of any? or is that as high as they go?

If, I drive reasonably on my daily 120 mile commutes (stop and go city and freeway), I am nearing 24 mpg.

I need to install the new Aussie intake gasket to get rid of a few vacuum leaks, then I can drop below a #57 jet to a 56 or smaller and maybe pick up a little better mileage. It is a tad rich with the #57. The plugs are a medium cinnamon color on 89 Cenex gas.

Thanks!
Author:  Doc [ Wed Aug 22, 2007 8:22 am ]
Post subject: 
Quote:
...I guess from what I hear you saying is that it is not a good idea to rebend the loop in the big spring, but find another one.
It would be nice to have another one "in hand" before you try to bend the one you have. Springs are heat treated into their shape and will sometimes snap if you try to rebend them... so have your "plan B" in hand if you try that. (yes, I have successfully opened-up the loop on springs before... I have broke them also)
DD
Author:  Aggressive Ted [ Wed Aug 22, 2007 1:31 pm ]
Post subject:  Distributor recurve
Doc,

Thanks for the reply and including the picture of the MOPAR distributor springs. It tells the whole story and puts all the discussions on recurving a SL6 distributor on this forum into perspective.

Thanks!
Page 1 of 1 All times are UTC-08:00
Powered by phpBB® Forum Software © phpBB Limited
https://www.phpbb.com/