3.0 cs Engine tuning tutorial with videos

[deQuincey]

I would like to share here something that i do at least every two years, and when i want to do it i always have to go through Reading the instructions and details again

this makes the job extremely disgusting as i always feel that i have to re-learn what i have forgotten because i do it once every two years ;-)

hope it helps...

so phase one: get started:

the setup:

additional tip: you must place a cardboard in front of the first carb (between the fan and the carb) to divert the air comming from the fan, otherwise the first carb will swallow more air than in driving conditions and readings will be useless.

p.s. video is shoot in the middle of a forest, forgive the birds,...

 

[deQuincey]

second step, as you should have a warm engine at full operating temp for any further step, lets wake up the beauty...

this is a bit of a surprise, as it is the first start after installing the Transistorized Electronic Ignition, so any mistakes in the conections will lead to failure or nothing to happen, moreover as i have installed new points and new plugs (resistive), who knows what can happen,...

the firs

now engine is warm, so we can start the procedure: first station: Check dwell angle, and set timing,...

 

[Ohmess]

I would like to share here something that i do at least every two years, and when i want to do it i always have to go through Reading the instructions and details again

this makes the job extremely disgusting as i always feel that i have to re-learn what i have forgotten because i do it once every two years ;-)

hope it helps...

so phase one: get started:

the setup:

additional tip: you must place a cardboard in front of the first carb (between the fan and the carb) to divert the air comming from the fan, otherwise the first carb will swallow more air than in driving conditions and readings will be useless.

p.s. video is shoot in the middle of a forest, forgive the birds,...

Thanks again DeQ. You are a great resource around here. I am using that same snychrometer, and that little tip about the first carb is something I did not know. Moreover, I am about to swap in a new set of plugs, change my venturis and tune all over again when I get my car back from California, so this is timely as well.

 

[Stevehose]

DCOE content:

The stock asymetrical 5 blade fan chops up the air pretty badly, this took me months of headbanging to figure out why #1 barrel would start flooding at 2500 rpm. With trumpets and foam filters (not the ramflow that fit flush to carbs) as well as the smoother flow 9 blade fan solved the issue.

Synching with the Synchronmeter I shelter the meter with my hands to even out the air fluctuations. With the extension tube it clears the engine pretty well.

 

[deQuincey]

and that little tip about the first carb is something I did not know. well.

yes,
facts, at 1700 rpms, so in the second stage of your synchro procedure, if you do not put a cardboard to shelter the meter you will read 2 kg/h more , this means that if you synchronize in that conditions you will get your carbs unbalanced and front carb will run richer

BTW you can find this tip in the manual

 

[Ohmess]

In Monterey, I was looking at the racing versions of our cars. I admired the cylinder specific sensors. Imagine the luxury of getting air/fuel ratios by cylinder!

 

[deQuincey]

setting ignition timing,

please check for mistakes, i can edit the video and upload a better version

 

[Stevehose]

I think I saw a speck of dust on the valve cover.

Do you check sync at idle and 3000 rpm? This ensures linkages are working for the entire range.

 

[Craig Bower]

I'd say you are dreaming if you saw a speck of dust on that engine.
Great video!

 

[deQuincey]

I think I saw a speck of dust on the valve cover.

Do you check sync at idle and 3000 rpm? This ensures linkages are working for the entire range.

thank you steve, sharp eye, now is clean, pfew ! ;-)

well, not at 3000, only 900 and then at 1700 tune the knurled nut, but i have never attempted a 3000, same procedure than 1700 ? rise rpms until 3000 and then tune the knurled nut to zero the balance ?

thanks

 

[Stevehose]

Yes, you may need a longer screw to get to 3k. Then check back at idle, then I usually split the difference or so. Hopefully it will be same at both rpm's.

 

[deQuincey]

Yes, you may need a longer screw to get to 3k. Then check back at idle, then I usually split the difference or so. Hopefully it will be same at both rpm's.

I will try this next time, thank you

 

[deQuincey]

so the final video: carbs synchro

please check for mistakes so i can edit a better versión

regards

 

[Philippe db]

DQ can I adopt you?

 

[deQuincey]

DQ can I adopt you?

oh, yes, i am clean and tidy, and purr like a happy kitten when it does not rain

 

[deQuincey]

so, are these videos ok ?
any evident mistakes ? (i know it might have been better if i had installed a shield cardboard at front carb,...)
any misspelling, anything to correct ?
i will delete the edition versión and leave them

P.S. i asume that lots of you have CSis or modified Css so these videos are not interesting at all, but i am surprised to see such Little feedback

 

[Philippe db]

Hi DQ,

I can imagine that lots of members look at the video's but if their technical skills are comparable to mine they only see a wizard at work. Somehow I know that what you're doing, using the technology you have at hand, must do miracles to these carbs but that being said I have no clue what this is all about hence my suggestion of adopting you. This for me is the only chance my carbs ever get tuned by somebody who knows what he's doing.

So I guess there are two kind of members watching you, the once with comparable skills not learning anything new hear, and the once with my technical skills, having know idea what is going on and can only dream of once understanding this. Neither are really in a position to write comments.

 

[Stevehose]

Looks good to me. I can only suggest that the engine may not run it's best at the lowest possible CO, especially after 40+ years. I'd try for a compromise between best idle quality and lowest CO (or for those with an AFR gauge, air-fuel ratio. Unless you have to pass an inspection of course.

I think Philippe has a point, those of us who like to dive in and try to do this ourselves will find it very useful, others will be thankful that they have a good mechanic!

 

[deQuincey]

dear steve and philippe, thank you for your replies,

 

[deQuincey]

Looks good to me. I can only suggest that the engine may not run it's best at the lowest possible CO, especially after 40+ years. I'd try for a compromise between best idle quality and lowest CO (or for those with an AFR gauge, air-fuel ratio. Unless you have to pass an inspection of course.ic!

this is a good suggestion, yes, when using normal points i had to leave co at 3,6%, no with tz i have been able to reach 2,8%

i agree that the target is best possible iddle quality vs. inspecion