finally it idles!!!
the combo: roller block with Callies 3.875 crank, forged pistons,..
..comp custom grind 230 intake 236 exhoust. 112 LSA
580 lift hid. roller on a superram.
Brodix 200cc heads and 1206 ported heads/manifold.

the fist start:The idle is fluctuating with the IAC in the 160 range, then back a little and then again to 160!

I had problems (not fully cured yet..) with the idle. I made a reset of the IAC and tried to set the air with the screw at the TB. I programmed in the chip a idle at 850 in gear ad 900 in N or P.

...So I tried to adjust the minimum idle to about 750 rpm without the aid of the IAC. (just to let the IAC using 20 to 30 steps to reach the desiired idle speed)

Nothing... the car cannot maintain a idle under the 1000 1200 rpm. I used ALL the screw adjustement in the TB to open the blades... Nothing... I have to use a bit of gas pedal to maintain up to 1200 rpm.

It seems that it needs more air to avoid stall... I also removed the vacuum line that goes to the Fuel pressure regulator (without capping the hole at the back of the Superram plenum...!) . the engine wants more air. Even with this added "vacuum leak" it want to stall.

At the end I decided to put back the IAC connector and do a little road test, with the idle going from 500 to 1500 erratically...

I had some problem putting the gear in (avoiding stall) but at the end i made the road test.

At the first stoplight it died... I started again and I can say that over 1500 rpm the car runs good, real good. At the next traffic light the idle was a bit better wih fluctuation from 7-800 to 1200 rpm... I put the D and it NOT died... at the next traffic light the idle was better and better up to the point to have a relatively stable idle around 750-950 rpm with minimal fluctuating sound.. I was with the scanner on and the IAC counts were at about 55-60 steps (with the adjusting screw on the TB near to the max ).

Returning at the garage to check for leaks the idle was near perfect in D (dacing from 850.875..900...825..850..875..925..875.. 850 .875..800..850.. it seems it want to stall but it not stal at all even moving the shift from park to R or from r to D...) Is this what it's called "lopey" idle?

The calibration is too rich now but I have 20 mins of datalog to adjust it. !!

I tried a bit to "push" the gas pedal... WOW! it's strong!! and it seems much more responsive and strong in the low rpms compared to the 219 cam even if this is a 230 intake duration and the heads a re 200CC intake with felpro 1206 intake ports !!

What is make me crazy is the idle management.
The fluctuating idle I had and not completely cured yet, (due to the IAC trying to compensate ) is often for some intake leaks. I'm pretty sure the Superram is perfect sealed ("sure" is what I think,.... ). So, if there is some intake leaks, the idle will be high with fluctuating up and down.
But, Why I have the IAC at 160 steps??? with all this amount of unwanted air not passing from the TB blades , the IAC should be near to 0. IT act like it WANTS MORE air..not less!
Why, it seems that if I add more air to enter it's better?
I have a 58 Holley TB .... when the IAC uses to run, it made a hissing sound where the hole in the TB is for the IAC. Is it probably that this passage is tooo little?
Thanks for your help.
-Beppe-

 

I wouldnt make any holes bigger or play with throttle blade opening just yet....Go back to checking for vacuum leaks/datalog. Try the smoke test on the SR to find your leak.

 

I have 57 Kpa map at 900 rpm in P
and about 64 at 850 rpm in D.
It seems reasonnable on a 230-236 cam with 112 LSA. not?
how to check for leaks ? I can try with smoke..but the car is getting hot , the fans are constantly moving air (the smoke too.. )

-Beppe-

 

Try increasing the spark advance at idle to something like 30-32 degrees if you haven't already done so.

This should help increase the vacuum which will help the engine to pull more air through the IAC or throttle opening.

I run 30.6 degrees @ 800 rpm and around 33-34 degrees @ 1000 rpm with good results with my 224/230 cam. 850 rpm warm idle in a 350 with SR.

I think with more cubes the 230/236 cam would be similar.

 

Tequila, thanks.
This should be done with the table "Spark advanceClosed Throttle vs.Rpm"? or with the spark main table at the correct rpm / map value?
The value I have now in this table ("Spark advanceClosed Throttle vs.Rpm")are:
4800 29.88
4400 29.88
...29.88
....29.88
...29.88
...29.88
...29.88
...29.88
...29.88
1200 27.42
800 24.96
400 24.96
0 24.96
the old value were :
from 0 to 800 20.04 deg
at 1200 24.96 and from 2000 to 4800 at 29.88.
-Beppe-

 

with smoke machine detector, u dont need to run car, infact they took out MAF and plug with an plastic cap, ur's is SD so u dont even have maf, smoke machine was the best i ever had to detect such a small leak on SR plenum top.

 

Beppe when i switched to ASM 58mm TB it even came with custom IAC housing as well, idle was way too high, no matter what i do, it idles at 1000 rpm. I found the problem with IAC housing it came with. So do u have stock IAC housing or this Holley came with its own IAC housing ?.

Or try swapping a stock TB temporarily just to see the diff.

I dont know much about tuning stuff, but this was my exp before i sold the car.

 

Smoke machine? How can it detect a leak if the engine is not running?

-Beppe-

 

SAmi, the IAC housing is the stock one. I have NO MORE the old TB...
-Beppe-

 

Beppe, I believe that the smoke is put into the motor thru the air intake pathway when the motor is off. It's got some pressure behind the smoke and it will leak out of any opening ( vacuum leak source ) that may exist in the intake pathway.

At least that's what I understand the test to be. I've never actually seen the test done, I have only listened to conversations about doing the test to find vacuum leaks. Sorry that's all I know...it isn't much but I figured I would offer it up anyway.:o


Tom

 

Yeah boys, the smoke machine will do ya proud. I have used the one at where I work several times. Most hook up to the battery, and have different sized nozzles to fit in nearly any vacuum line. I have had the most accurate, fastest diagnoses from inserting the nozzle in the PCV vacuum line, but any vacuum line will work. Insert nozzle, push the button on a hand-held controller, and the smoke tells the story. You can leave all intake parts intact. Same thing can be accomplished by cigarette smoke blown into the engine - there was a thread recently about that. Maybe you can rent one Beppe.

 

Thanks, I doubt i can find one here in Italy..
I doubt I have an Intake leak... I installed the superram paying attention at every step following every advice in the forum. In addition I installed the SR at least three times in 2 years and I know every single bolt of it. The intake gasket has been checked 1,000 times and i used also the "right stuff" rtv.
every single bolt is coated with this silicone, every maching side of runners, plenum, base are with gasket and the "Rifìght stuff".
Unless I have an Internal leak due to a crack under the base... I' pretty sure i haven't leaks.
In addition the datalog is telling me that I have too much fuel at idle and I'll try also to bump a bit the timing a t Idle. (the new chip is ready to be tried )
Tequila is saying that at idle he uses over 30 deg with good results.
Another factor is that the O2 sensor ends to do its work expecially in P due to the fact that it will cool (its too far away fom the engine in the headers....I have to install the heated sensor I have..

The last thing:
Coul someone give me a correct definition of "cam lope" ?
and a definition of "surging" (IF the two words are a different means)...

thanks
-Beppe-

 

I had a leak when I installed my Superram. I found it by spraying throttle body cleaner with the engine running. The RPMs will increase when throttle bottle cleaner is sprayed into the vacuum leak. You're probably aware of this method. If you're running too rich an adjustable fuel regulator may help. Maybe you just need to install that new custom chip. Cam lope is the choppy idle caused by the cam. It is not a problem. Surging is when the engine idle speeds up for no apparent reason and should be corrected.

 

Beppe,
As mentioned, lope is a slightly choppy idle. When the tune up is under control, I suspect the cam lope will be slightly rougher than your las 219 combo. Lobe seperation on this cam is 112 and the 230 ish duration is not alot for 396 cubes. Once it is sorted out, I bet you are gonna like it. Let the fun continue

 

Pete, the fun's just started!
The engine runs strong and it seems more streetable than the old one with the smaller 219 cam.
Just tried some WOT operations and i can say "WoW".
With my big surprise at my return to the garage the mechanic said: " you say it runs strong?... strange... I have not yet finished the modify to the throttle body lever... you are at WOT openingg not more than 60%- 70% ..." !!!!

Changed the oil and filter ..and the oil seems almost new.
the high oil pressure continue.. ... even if I reached 227 deg oil temp .
at the minimum throttle opening it jumps to 80 psi.
Sunday I have the opportunity to do about 150 miles coming to a local racetrack (not 1/4 mile..) . I'll stay conservative until I'm not sure about the tune, oil leaks, vacuum leaks and others small things..

-Beppe-

 

The 383 that is inmy car currently has high oil pressure as well. Similar to what you describe. I too have the melling standard volume pump. I wonder if Melling is slipping high pressure springs in them.
I would imagine that the cylinder heads are the main thing contributing to the wicked throttle response. I hope you work out the small issues and take it to the race.

 

The oil pressure on my 396 seems to be a tad high too. I have however noticed that after driving it a bit more and having the oil breaking in, the oil pressur has seemed to come down some. What kind of oil are you running?

 

The problem is here... the oil..
As stated everywhere the oil to use at the break in should be regular oil. Here in Italy it's impossible to find 5-30 dino oil, you will never find oil less than 15 w40 petroleum based.
You can start to find something "thinner" when you look at synth-based motor oils. And here you can find a 10-40.
To go in the 5-30 , 5-40 or thinner you have to go fully sinth.
I have a 15 40 now
Is it safe/correct to put in a synt based motoroli (even in the first time of break-in) just to have an oil a bit thinnner?
-beppe-

 

Smoke machines are da bomb!!!! Its one of those things that after you own one you cant believe you lived with out it. Every good diag shop should have one. The make even the hardest to find vacuum leak a piece of cake. They work real well for vacuum leaks in evap systems on OBD2 stuff. They have very little pressure. Just enough to force the smoke in and then out of a leak.

 

I'm interested in your impressions of the camshaft.

I'll be running much the same cam in the 388 I'm building now, except my cam is on 113 LSA not 112 like yours.

So when you have a chance, I'd really like to read about your driving, idling, throttle response impressions and experience.

Good luck with the new engine.

Thanks,

Jake