First batch of parts arrived, first batch of questions
03-15-2018, 08:42 AM
#1
Pro
Thread Starter
First batch of parts arrived, first batch of questions
Hi guys!
UPS came today ( darn them, they overcharged me a lot on the brokage costs, that'll be a fun e-mailing history..)
Anyway, I have questions about a few parts I've ordered, and would like cmfirmation.ideas on some others :
-Summit advance recurve kit: The gold springs (weakest) look like they're still too stiff for our cars, correct? Im using a lunati 280/290 cam ( much like the popular comp 268) so I'd say I need the advance all in at 3500rpm, not 5000 rpm?
-The lunati cam/timing gear kit:
This cam sheet is here:
I have the lunati double roller timing chain kit (94200), with 3 sprocket positions. Wich one do I need? They don't specify wich sprocket hole is wich. Does anyone know this? Or know where I could find the info? The instruction sheet just says : 'locate the keyway with the desired advance'.
If no one knows I'll just get my dti and timing gear out..
And for those looking for a rag joint replacement, I ordered borgesons 000941, it looks like it'll be a good part! With the right shouldered bolts etc. 8 layers of metal.
No doubt there will be tons of more questions soon, I'll need to buy each of you a(few!) drinks when I come to the USA
cheers
UPS came today ( darn them, they overcharged me a lot on the brokage costs, that'll be a fun e-mailing history..)
Anyway, I have questions about a few parts I've ordered, and would like cmfirmation.ideas on some others :
-Summit advance recurve kit: The gold springs (weakest) look like they're still too stiff for our cars, correct? Im using a lunati 280/290 cam ( much like the popular comp 268) so I'd say I need the advance all in at 3500rpm, not 5000 rpm?
-The lunati cam/timing gear kit:
This cam sheet is here:
I have the lunati double roller timing chain kit (94200), with 3 sprocket positions. Wich one do I need? They don't specify wich sprocket hole is wich. Does anyone know this? Or know where I could find the info? The instruction sheet just says : 'locate the keyway with the desired advance'.
If no one knows I'll just get my dti and timing gear out..
And for those looking for a rag joint replacement, I ordered borgesons 000941, it looks like it'll be a good part! With the right shouldered bolts etc. 8 layers of metal.
No doubt there will be tons of more questions soon, I'll need to buy each of you a(few!) drinks when I come to the USA
cheers
03-15-2018, 09:44 AM
#2
I cannot read any of those pictures. Sorry.
03-15-2018, 01:59 PM
#4
Pro
Thread Starter
03-15-2018, 02:04 PM
#5
That curve kit doesn't look performance oriented to me. Lets see what Lars says, but I say don't use it for now.
03-15-2018, 02:26 PM
#6
Looks like the MSD kit has a better spring selection
https://static.summitracing.com/glob...s/msd-8428.pdf
https://static.summitracing.com/glob...s/msd-8428.pdf
03-15-2018, 04:35 PM
#7
Team Owner
Member Since: Jan 2007
Location: Southern Cal Ca
Posts: 50,467
Received 762 Likes
on
613 Posts
St. Jude Donor '22
timely thread.
i have a thread, "camshafts a discussion"
trying to deal with ignition timing per cam requirements.
may not help since the ole
:set timing to 36 deg all in at 3k"
won't go away.
so,
you want a spring weight combo that
moves to its maximum travel at 3k rpm.
if i could read the pics, maybe my requested info is there.
like base timing, what rpm the centrifugal adv should start,
what rpm it should stop.
studying gm dist specs
adv starts anywhere from 800 rpm and stops at 5500 rpm
to starts at 1200 rpm and stops at 4200 rpm.
then the total adv is all different also.
i have a thread, "camshafts a discussion"
trying to deal with ignition timing per cam requirements.
may not help since the ole
:set timing to 36 deg all in at 3k"
won't go away.
so,
you want a spring weight combo that
moves to its maximum travel at 3k rpm.
if i could read the pics, maybe my requested info is there.
like base timing, what rpm the centrifugal adv should start,
what rpm it should stop.
studying gm dist specs
adv starts anywhere from 800 rpm and stops at 5500 rpm
to starts at 1200 rpm and stops at 4200 rpm.
then the total adv is all different also.
03-15-2018, 07:36 PM
#9
Le Mans Master
Member Since: Aug 2017
Location: Cool Northern Michigan
Posts: 6,904
Received 2,128 Likes
on
1,635 Posts
UPS in Belgium? H-m-m-m-m. And my UPS driver complains about his long route. Anyway:
You don't have to pair-up the dizzy springs per color. You can mix & match. I believe a real popular choice with the MSD kit is one Silver & one Blue spring to get the desired curve. Keep in mind those weights really like to swing out due to centrifcal force when spinning at a couple grand too. So you can't judge the tension feel of the spring with fingers. The bushings color / size will limit maximum advance built into the curve.
Should be a drawing somewhere of the crank sprocket indicating what each symbol / keyway is worth in degrees. Keep looking for it. Most people in Belgium choose zero degrees or straight up. The other marks might be 4* advanced and 4* retarded, neither of which you want for the street.
You don't have to pair-up the dizzy springs per color. You can mix & match. I believe a real popular choice with the MSD kit is one Silver & one Blue spring to get the desired curve. Keep in mind those weights really like to swing out due to centrifcal force when spinning at a couple grand too. So you can't judge the tension feel of the spring with fingers. The bushings color / size will limit maximum advance built into the curve.
Should be a drawing somewhere of the crank sprocket indicating what each symbol / keyway is worth in degrees. Keep looking for it. Most people in Belgium choose zero degrees or straight up. The other marks might be 4* advanced and 4* retarded, neither of which you want for the street.
Last edited by HeadsU.P.; 03-15-2018 at 08:24 PM.
03-15-2018, 08:21 PM
#10
Dr. Detroit
Member Since: Mar 2012
Location: New Braunfels Texas
Posts: 9,963
Received 3,892 Likes
on
2,564 Posts
Do not use that spring kit. HeadsUP is correct on the silver and blue spring.....but only in a MSD distributor.....it will be different in others.
With the Lunati.....there will be a Triangle, a Square and a Circle......go with the circle.
Jebby
With the Lunati.....there will be a Triangle, a Square and a Circle......go with the circle.
Jebby
03-15-2018, 08:51 PM
#11
What kind of distributor are you using? Tach drive, HEI, or aftermarket?
Please be specific.
Please be specific.
03-15-2018, 08:59 PM
#12
The three holes in the timing sprocket are so you can 'degree' your cam to actual top dead center. Usually each hole represents 4 degrees. You can 'Google' degreeing a cam.
Last edited by RU7376vettes; 03-15-2018 at 08:59 PM.
03-16-2018, 06:20 AM
#13
Pro
Thread Starter
<br />Doesnt really matter does it? As were just discussing the ignition curve..? HEI btw.<br /><br />Seems like ill be ditching the spring set for a new one. Amazing how they even sell this kit,it seems pretty useless.<br /><br /><br />I know how to degree a normal cam, but I dont know at what this cam should be timed ( being asymmetrical too). 107° on the first intake lobe? + 2 degrees for initial stretch?