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Rough Idle

 
Ravoll Ravoll
V-6 Camaros rule! | Posts: 85 | Joined: 02/12
Posted: 03/02/12
12:05 PM

Yeah Pepsi,
Feel bad about correcting ya too.But thats the way we were "teeched n skool".I was
turning screws on this thing day before yesterday and was noticing my PCV was fluttering.Took it for a drive with the air cleaner off and at about 60 kicked it down and opened the four barrel briefly.Could hear the same fluttering coming out of the secondaries and absolutly no grunt.Went back to the garage and got to thinking I have valves not closing completely.Did some research online and found out, the lifters that came with my cam pump up really hard.15W40 and 45Lbs oil preasure at idle probably compounds the issue.Since they were 1/2 past zero I backed of 1/4 and the fluttering is almost gone.The vacuum came up about 3 inches,but still no real power. Prepped me some old valve covers today and will run a hot adjustment on the lifters in the morning.Gonna back em off till they tick and run em back down just till they stop ,with the V-guage hooked up to see if it changes anything.  
The older I get,the faster I was.

pepsi1 pepsi1
Big Block power for the win | Posts: 940 | Joined: 03/11
Posted: 03/02/12
09:50 PM

Ravoll

HUMM....seems like someone suggested that back a few frames...LOL... Yeah we older guys have been picked on for awhile now. If you get CHP magazine May issue 2012 page 10 in the Q&A there are some older guys saying the same thing noone respects anyone anymore.

Back in my day my father would have had his Size 11 burried so far up (you know where) you could look in my eyes and see the shoe.....LOL...I hope until I see my last Drag Racing Christmas Tree that I keep learning! Grin  Cool
Thanks,
Bob  

Ravoll Ravoll
V-6 Camaros rule! | Posts: 85 | Joined: 02/12
Posted: 03/03/12
03:45 PM

well Pepsi,
We nailed it.Running Zero lash with just a tick preload.Vacuum up to 16" wavering 2 or 3 up and down.Idle is smooth, with snappy throttle.The fluttering is gone.Runs alot better but still don't have the punch I was expecting.Don't notice much improvement over my stock cam.Also no lope at idle.If I didn't know better I  could swear I put the stock cam back in.Not feeling it was worth the money I spent.


Alan  
The older I get,the faster I was.

pepsi1 pepsi1
Big Block power for the win | Posts: 940 | Joined: 03/11
Posted: 03/03/12
11:23 PM

Ravoll

The Comp Cam you have is good from 1300RPM to 5600RPM. (NOT FOR anything Ravoll) that's not the cam I would have choosen.....My 2 Cents...

You listed everything  except the rear gear ratio. Your Vette should have aleast a 3:70 to 3:90 rear gear and this cam will work fine. It will give you that punch your looking for.

I maybe getting ahead of myself thinking it has that gear ratio? It may have a 2:92 or a 3:08 gear. That's when GM was looking for MPG? But let's see if something else is out of wack.

What RPM are you turning at 60MPH ?

Do you know what rear gear the vette has? I'm sure it's a Posi rear so it will be easy to find out. Mark the driveshaft and Mark the tire. Turn the wheel forward and count the  Driveshaft Revolutions to One complete Revolution of the wheel. That's it.

Did you put the cam in straight up?

Did you have the distributor checked to make sure it's function properly. If so do the next thing. To make sure the vacuum adv. is working properly.

Try setting the BASE timing at 10 degrees at idle and remove the vacuum advance line and plug it just for this set-up.

Now set the timing at 30 Degrees and all in at 2200 to 2500 RPM. If it feels better Dial in another 2 Degrees. I would not go anymore then 34 to 36 degrees as it may start to PING GAS TODAY SUCKS. Unless you can get some good gas. I have a friend at the airport and I mix AVGAS and 93 50/50. My son runs the AVGAS straight for his bike.

Give this a try I would check the rear gear ratio first,and if you have a 2:92 or 3:08 disregard all the things I've said.
Thanks,
Bob

Isn't that the truth the older I got the faster I wanted to go. My 1966 ChevyII could have gone into the 8's for 1/4 mile, but I sold her. I had that car from 1972. All the sheet metal was original except the R/F fender. It was  backed into it at the track and he took off. It was easy enough to find him. He said he didn't feel or hear it. Given that when your in a race car the noise and people around is enough confusion I understand that. But to say it wasn't me. Well him saying that cost him a year from running his car at that track and 2 tears of probation. Plus he had to fix the damage.......I also had a 1968 Big Block Camaro that was my fun car....I ran 11:20's @118MPH 1/4 mile. The 375 Horse  396 was from my buddies 1968 Corvette. Back in the day you could buy a complete engine for $1,000. He purchased a complete  435 HP 427 with the solid cam and a Tri-Power set-up.That was an original numbers matching engine. Thats why I said it was my fun car. I never wanted to hurt it.

I just put an ad in Hemmings Motor News and the first Pulication it was in I sold my ChevyII. The guy never saw the car (Hemmings Didn't have a PIC yet) sent me a check as a deposit. Came up to look at it. Said he would be back with a trailer. The day he came up to pick it up he brought a friend who also had a car trailer, he purchased my Camaro. He told his buddie about my Camaro and sold both cars.....Never had anything work that way before,emptied the garage in a heart-beat.....I never advertised my Camaro. I had a total of 21 calls about my ChevyII before they were able to take the ad out.....
Bob  

Ravoll Ravoll
V-6 Camaros rule! | Posts: 85 | Joined: 02/12
Posted: 03/04/12
01:59 AM

Pepsi,
I chose this cam cause it's what I was recommended by the comp tech advisor.I was told it was the sharpest grind I could use with my stock converter.
Thing is, I run this vette here in Germany with a historical registration.
Any changes to the originality can or will void this.That means 3K a year tax on top of the now 8 bucks a gallon.So I really need to keep the stock appearance on the outside.

Cam is installed straight up.Timing is set 8° base (no advance)at 800 RPM.At 2500 RPM I'm tagging about 28° all in.Any more than that ,I have starter drag warm.

Differential is 3:55 with 255/60 15H Bridgestones.TH 350 with typical 2.52/1.52/1.0 ratios,and stock 1500 stall.Tach shows 2700 at 60MPH.

Other factors that may or may not contribute are:
Stock spreadbore intake.
Stock ram horn exhaust manifolds.
Stock 2/1/2 exhaust through a stock monolithic cat.  
The older I get,the faster I was.

pepsi1 pepsi1
Big Block power for the win | Posts: 940 | Joined: 03/11
Posted: 03/04/12
05:49 PM

Ravoll

I didn't know that about the historical society. It was just my opinion that's all! These are observations of mine thats all Ravoll. (Could you stuff a 350 Horse power 327 cam in it and still be OK)? That is still a nasty cam and runs it heart out.

I'll tell you everything you have listed will not hinder the performance of your engine.

Going by your Tach reading your almost in the middle of the power band.THATS GOOD...

1.The strater drag is a problem. Does the starter have a heat shield on it?
There is also a brace on the nose of that heavy starter is that there? The brace keeps the starter from bending.

The only thing check your harmonic damper, and see if it has spun on the center? The Elastomer thats between the two parts sometime will move and when you set the timing it's incorrect. See if the Elastomer is soft. I've seen this happen more then once.

If you have a way of finding TDC on #1 Cylinder and then see where the timing mark is.

Just something else to try. Check the PCV valve is it sucking and when you put you thumb over the valve does the engine want to stall?

I would just put a timing light on it and see if the distributor is advancing.

Bring the plug gap down to .025. If you can run a step colder plug. I don't know how hard parts are to come by in Germany.

I'm stumped it may all go back to the carb. Are the secondary's opening. Boy this is a time when I would like to have it in my shop. I just love problems,but I have to have my hands on it...LOL...

Ravoll there are things to try but it will take going back over a few things inside.

There is NO real reason that shouldn't set you back in the seat. I mean that! Have you tried running it through the gears and holing the RPM to 5,200 each gear, and see if there is one place where it falls on it's face (Runs out of power).
Let us know.
Thanks
Bob  

Ravoll Ravoll
V-6 Camaros rule! | Posts: 85 | Joined: 02/12
Posted: 03/05/12
11:17 AM

Hi Pepsi,

Starter drag is from to much advance I think.when it drags I can pull by distributor back a bit and it starts no problem.Starter is new and yes the brace is there.Don't know that it ever had a heat shield,but not one there now.

The balancer is also for me a known problem causer.Esspecially if "bubba" was beaten it with a hammer.But no it's fine.TDC points to 0 advance.Timing index on the timing chain cover only goes to 12 by the way.If I set it there with the light,
it reaks havoc on my starter.

PCV is new and it works.

Timing advances both vacuum and mechanical.Complete distributor was put on new last summer.I am running full/constant vacuum advance at idle.I know this should be metered,but chevys always seemed to hang on the throttle better at cruising speed with constant.

THE PLUG GAP WAS MY NEXT TRY. AC delco say's  R45T's for this year model vehicle,and engine,the proper gap is 1.01mm.Thats where they are now.I made sure back when it didn't idle correctly.AC's specs don't take into consideration that my air/fuel ratios have changed ,what with the cam and missing EGR all.So I was gonna close the gap a little and see.

I also think it might be running a little on the rich side after messing with the jetting last week. It'S got 0.072 jets in it now with 0.047 metering rods.Gonna keep the 72's and change the rods to 0.054 and see if it pulls better.Secondarys are opening .My son said it can be heard all up and down the valley.
It don't fall on its face.It revs fine through the powerband.Just don't seem to have the "Umph" that the stock cam had.Motor is new so I haven't taken up past 4500.Need a few more miles before I can, or would want to, get down and thrash on it.A little wary that by the time I get it to run how I want,the bottom end will have a wobble.L48's are only 2 bolt.No Power = dry revs.Not my thing

Haven't given up  
The older I get,the faster I was.

pepsi1 pepsi1
Big Block power for the win | Posts: 940 | Joined: 03/11
Posted: 03/05/12
02:13 PM

Ravoll

Maybe drop the jet size to 68 and see how it goes. Grin  Cool  

Maybe if you do that give some break in time. The two bolt 350's are good for 450 to 500 HP.

MSD makes a Retard timing box. I have put 2 switches in the car you can use the ignition key. Use the key to spin the starter and the second switch to turn on the ignition. Hope that makes sense to you.
Good luck Grin  Cool
Bob  

Ravoll Ravoll
V-6 Camaros rule! | Posts: 85 | Joined: 02/12
Posted: 03/06/12
11:43 AM

Hi Pepsi,
I used to do that with my old 70 Camaro.Crank it till the oil pressure come up and then hit the switch.  
The older I get,the faster I was.

redneckjoe69 redneckjoe69
Everything in my driveway’s a Chevy | Posts: 612 | Joined: 02/10
Posted: 03/06/12
01:26 PM

i use a system like that,...key for starter, toggle switch for the ignition.   its easyier on the starter and kinda burgalar deterent if you hide the switch.   have done it many times with great results.  good tip Pepsi!  Cool        any progess on the condition lately?  

Ravoll Ravoll
V-6 Camaros rule! | Posts: 85 | Joined: 02/12
Posted: 03/07/12
02:44 PM

Hi All,
Still running on all eight I guess.Got bad weather here,misty,cold and foggy all week,so haven't been out with her.

Still a bit bewildered about the valve setup.Have never in my life seen hydraulics that have to be set like solids.
Was doing some reading about the ramping times between hydraulic and solid cams.The way I understand it is, hydraulic cams have a slightly different ramping time to allow the lifter plunger to compress a little before the valve is actually lifted off it's seat.The solid lift cams use faster/shorter ramp cause there's no need to wait on the lifter to compress.
If you were to use solid lifters on a hydraulic cam,since the solids don't compress it would cause the valve to open prematurely due to the hydraulic ramping phase on the lobe.On the other hand,if you used hydraulic lifters on a solid cam, the faster shorter ramping would'nt allow the lifters time to set.Would be kinda like opening each valve with a hammer.The hydraulic lifters would have kind of a "shock absorber" effect.Push on them slowly(Relativly speaking)with the slower /longer ramping,and they compress.Slam on them with the faster ramp of a solid lift cam,and the oil can't get out of the way fast enough and the lock up,causing the valves to stay open.

My point is, the way it's acting when the lifters are 1/4 turn preloaded,I almost have to think I may have a solid cam with hydraulic lifters.
Only one way to be sure. Tongue  I really don't want to tear the cam back out to check the grind numbers.According to my cam card it's correct.I was trusting and didn't look before I installed it.  
The older I get,the faster I was.

pepsi1 pepsi1
Big Block power for the win | Posts: 940 | Joined: 03/11
Posted: 03/08/12
11:07 PM

Ravoll

If you want to get the numbers all you should have to do witch is still a *** is take the timing cover off and pull the cam pulley. The numbers should be under that.....

You would have worn the cam and lifters down to nothing by now...LOL... What the cam guys are trying to do is use all the area under the curve but not destroy the valve train. In short the cams are ramping so much faster but you still have the quietness of the hydraulic lifters.

Your cams all broken in maybe if you run through the valves again you may have one thats touchy if you know what I mean. Grin  Cool

Now you have to do it with twisting the pushrod between your fingers. Disarm the ignition. Pull the spark plug from one cylinder at a time.Each cylinder should be on it's compression stroke. The piston you should feel with a small piece of machanics wire. Back the adjusting nut of rocker arm off slowly, as your doing that put your fingers between the pushrod of the lifter you want to adjust and twist the push-rod so you can feel the lifter unload, the push-rod will spin easy. Now while twisting the push-rod adjust the nut until you feel the push-rod stop spinning. Now adjust the rocker arm I like a 1/8 turn go 1/4 turn in and go on to the next one. Now as you go along you will get loose rocker arms on the ones you have adjusted leave them alone. They will bleed each time they make a cycle.....See if this helps..... It would be a *** to put a cam in that now........LOL.......Let me know if your going to change the cam?
Bob  

pepsi1 pepsi1
Big Block power for the win | Posts: 940 | Joined: 03/11
Posted: 03/09/12
02:47 PM

Ravoll

Just to add to the finding of your Cam Numbers if you do that you can try pushing the Cam 2* degrees advanced. See if that helps.

You know you brought up an interesting situation I remember reading an article on that subject of anti pump up lifters. I found it and it's very interesting. It's lengthty so I'm going to try and cut it down. Grin  Cool

This is to maintain Zero lash
1. As engine rpm increases the bleed-down rate inside the lifters may be too great. There may not be enough time to refill with oil between each valve cycle,in turn causing the lifter to collapse. Or if the bleed-down rate is too low and the lifters retain too much oil, they can pump-up and overextend the valves. Either way that these events occur you can have either way with valve float or misfiring, and loss of power.

2. The rev limit of a typical stock hydraulic valve limit is 6,200 to 6,500rpm. If you want to rev your engine higher then this you either need solid lifters or a modified performance lifters that can safely handle  higher rpms without pumping up or collapsing.

3. Hydraulic lifters that have an anti pump-up design are made with tighter internal clearances and/or special valving to reduce the bleed down rate. Anti pump-up lifters allow higher engine speeds and are a good choice for dual-purpose street/strip engines. One supplier of such lifters says their anti pump up lifters can handle engine speeds to 7,500 rpm with NO valve float and can even be used with many camshafts that are designed for solid lifters.

So like we have discussed over the last few posts that an anti pump-up hydraulic valve lifter can be used with a solid lifter camshaft...... I don't know if I would be the first to try this because of all the CRAP with camshaft break-in and ZDDP thats not in engine oil anymore BLAH,BLAH,BLAH.....

There was an old school way we made hydraulic cams work like solid lifter cams. We would bottom the hydraulic lifter until all the free movement was gone. Then adjust the rocker arm until it had .003 to .010 lash. We left them at that and the cams would rev until the vavle springs couldn't keep up.

There are so many variables to selecting a cam that most people don't realize. I've had cicrle track guys come in my shop with a cam they purchased from another driver who told them that was the best came for blah,blah,blah track. Most times the cam will not work........ So when you guys that send your specs to your engine builder include everything you can think of. Grin  Cool

Remember you are paying good money for your engine builders wisdom and experience,your engine builder is only as good as the information you give him.I have not been pleased with a cam a customer has brought to me. Then I would get well the guy that sold me this cam said it worked for me. There are way too many variables into choosing the correct cam as there are choosing the incorrect cam....... Grin  Cool
Ravoll I have other info if you need it.
Bob  

Ravoll Ravoll
V-6 Camaros rule! | Posts: 85 | Joined: 02/12
Posted: 03/22/12
01:09 PM

Hi Bob,
Got about 400 miles down
It's running much better now.Think the valves have worked themselves a proper seat.

Timing set 15° base,20° with Vacuum and around 30° to 31° all in at 2500.No ping under load.

Still running 0 lash, with just a tick to get off the clips.No rocker noise.
Been up around 6K (under load of course)with no banging out.

Set the ATP to accomodate my mods/jet and rod changes on the Q-Jet.Was kinda flat on the primaries.Very noticable on the shift.Like I was lightly giving it gas and was'nt getting faster till the secs. kicked in.Thats gone now.Pulls smooth on the primaries through all gears.No more bogging

Tightened the flaps on the secondaries so they pull open smoother instead of just falling open,causing the dreaded secondary stumble.

Still , out of the hole,till about 2300, I aint impressed.2500 to 6K it's comes alive.I was wondering something so I eased down on in 1st gear till about 2000,stomped it flat ,and didn't shift into second till 6K.It was still pulling  when I shifted.Freaked my old lady a bit when it grabbed second.(Will be putting the B&M sticker on tonight).

Think I'll be looking towards a 2k stall converter or so,to get up over 2000 on launches,but still keep it drivable in traffic.

I think truly I will just have to adjust to this cam and where my engines making power now,as compaired to before.The stock cam pulled strong out of the hole till about 4500 but anything after that was just noise.I was expecting the same from this cam but instead of the fun being over at 4500,it would carry on till I got scared.Not the case.This cam only took my low end torque and moved it into the midrange.Not really what I was looking for cause I don't run Autobahn with this car, but I think I can get some fun out of it from stop light to stop light Grin

I already thought about advancing the cam, but it will lower my intake valve clearance.The only safe way to do that would be an expensive degree wheel and opening the motor up.Maybe in the winter.I want to do some port work anyway.
Still have to put new T arm bushings,half shaft U joints, and bearings and seals in the differential first.Needs em bad.Will most likly be my next thread to bug you with.

Alan  
The older I get,the faster I was.

Ravoll Ravoll
V-6 Camaros rule! | Posts: 85 | Joined: 02/12
Posted: 03/22/12
01:09 PM

Double post deleted  
The older I get,the faster I was.

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