Just checking CAM retarded 2° influences at the BIN
Thread Starter
Member
Joined: Nov 2003
Posts: 299
Likes: 0
From: The Netherlands
Car: Cobra Kit Car
Engine: 350 HSR
Transmission: TKO 600
Axle/Gears: 3.31
Just checking CAM retarded 2° influences at the BIN
Hi,
I am just checking if I am right.
I have install the CAM with 2° retard (that is the CAM timing).
To get the power band at a higher rpm level and perhaps gain some ponies.
At the bin I keep the 6° initial timing (that is the ignition timing)
The CAM was not degree but just put at the square slot pointing the dot.
If I am right I should keep the 6° at the bin, isn't?
I should also put the distributor with the timing light to the BIN specified 6° that is just to start with.
What are the normal steps, first change the 6° for 8° at the BIN and than adjust the distributor?
Of course I should do some work at the main SA table too.
I try to get ideas from others to give the engine what it wants. (some one say that before?)
Have you guys played around with this CAM retard and than change the BIN to get the best?
Regards,
Cobra289
I am just checking if I am right.
I have install the CAM with 2° retard (that is the CAM timing).
To get the power band at a higher rpm level and perhaps gain some ponies.
At the bin I keep the 6° initial timing (that is the ignition timing)
The CAM was not degree but just put at the square slot pointing the dot.
If I am right I should keep the 6° at the bin, isn't?
I should also put the distributor with the timing light to the BIN specified 6° that is just to start with.
What are the normal steps, first change the 6° for 8° at the BIN and than adjust the distributor?
Of course I should do some work at the main SA table too.
I try to get ideas from others to give the engine what it wants. (some one say that before?)
Have you guys played around with this CAM retard and than change the BIN to get the best?
Regards,
Cobra289
Joined: Mar 2000
Posts: 1,692
Likes: 1
From: Corona
Car: 92 Form, 91 Z28, 89 GTA, 86 Z28
Engine: BP383 vortech, BP383, 5.7 TPI, LG4
Transmission: 4L60e, 700R4, 700R4..
Axle/Gears: 3.27, 2.73
Re: Just checking CAM retarded 2° influences at the BIN
Cam timing isn't a BIN related thing at all, so there's nothing specific to change. But, being retarded and later closing intake valve will probably want more low RPM timing in general.
The distributor base spark timing should be manually adjusted for quick run-up of the engine during cranking, and the BIN should have the same number (change it if you are not using the stock base timing). Anywhere between 6 and 16 depending on the cam and compression.
What is your intake centerline now? If too retarded, you'll be losing bottom and top (or at least area under the curve).
The distributor base spark timing should be manually adjusted for quick run-up of the engine during cranking, and the BIN should have the same number (change it if you are not using the stock base timing). Anywhere between 6 and 16 depending on the cam and compression.
What is your intake centerline now? If too retarded, you'll be losing bottom and top (or at least area under the curve).
Thread Starter
Member
Joined: Nov 2003
Posts: 299
Likes: 0
From: The Netherlands
Car: Cobra Kit Car
Engine: 350 HSR
Transmission: TKO 600
Axle/Gears: 3.31
Re: Just checking CAM retarded 2° influences at the BIN
Cam timing isn't a BIN related thing at all, so there's nothing specific to change. But, being retarded and later closing intake valve will probably want more low RPM timing in general.
The distributor base spark timing should be manually adjusted for quick run-up of the engine during cranking, and the BIN should have the same number (change it if you are not using the stock base timing). Anywhere between 6 and 16 depending on the cam and compression.
What is your intake centerline now? If too retarded, you'll be losing bottom and top (or at least area under the curve).
The distributor base spark timing should be manually adjusted for quick run-up of the engine during cranking, and the BIN should have the same number (change it if you are not using the stock base timing). Anywhere between 6 and 16 depending on the cam and compression.
What is your intake centerline now? If too retarded, you'll be losing bottom and top (or at least area under the curve).
Been there several times for engineering purposes and I like the way of thinking. (But sometimes.......)
"Use all the possibilities" Just amazing hoe they manage every time.
Anyway.
I am underway to have the first start of the new engine (plan to be at the end of august.)
So I am preparing all the things and one of them is the BIN. I will use the S_AUJP_v3 if not better with some self made changes to accommodate the stick (M/T) so a combination of S_AUJP and AXCN.
That means that the base timing is set to 6° at the BIN and the distributor has been set to the 6°, but need to be check during the first start.
My static C/R is 10.02 but now I think that I have changed the Dynamic C/R due to the 2° retarding using the cam specks it should be 8.26 but I need to dig in in this matter to find out the consequences.
You ask for my ICL
I think that the ICL is @ 112° my CAM is an ISKY and has the next figures @ 0.05" lift.
Intake duration 209°
Open BTDC -7.5° Close ABDC 36.5°
Exhaust duration 217°
Open BBDC 40.5° Close ATDC -3.5°
The LSA is 112°
The actual ICL was not measured, I just used the gear slot at the chain to get the two degree retard.
I think that I am getting confused and don't know what I am doing, though to put the power band at a higher rpm, but looks that I am loosing Dynamic Compression too. Of I am wrong with this one too.
What I am doing? I am lost
I did retarded all the events "Open" "Close" etc. related to the crank but that is only when the cam has been perfect fabricated, right.
Oh! ge! I thought just change a bit the BIN after dial the base timing and I am done, but looks like I should play around till I get it the best of it.
Oh! I forgot it is just a hobby, so why not play with it?
Thanks.
Regards,
Cobra289
Thread
Thread Starter
Forum
Replies
Last Post
