Roller cam idle RPM

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megacab

megacab

Leglhi
Joined
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Nipomo California
Hey everyone.Hope all is good.I was hoping you could shed some light on the idle speed i should be running in park and in gear.The engine is a fresh combo,and it now has a 712/698 lift,276/280@50 duration Bullet roller in it.Im running a dominator and it's got 14.1 Ross slugs in it.It doesnt sound much like a street engine,but i drive it to the donut shops on Saturday and around town sometimes.I know i shouldnt have to worry about flattening it,but i heard that in order to get good oiling to the cam it has to have a high idle speed.Problem is it's brutal to drop it in gear when its to high.And of course it drops decently when its in gear.I like it at about 12-1300 in park,which is about 900 or so in gear.Whatsyour thoughts on this?Is it hard on the cam idleing low with 625# springs?Thanks everyone :burnout:
 
Wouldn't a higher stall converter make it less brutal when you drop in gear and still have the higher RPM to keep you cam lubed? I've never heard of having to have RPM to keep the cam lubed but with that mean beast it might need that. Dynamic converters might can through you some suggestions. They are very good in what they do.
 
Yeah your right about the converter.Its a Turbo Action 3800-4200 that i bought from a friend that was running it behind a 440.Havent had it on the track,and im not sure what it will foot brake to.I do know it was a tight converter.I have a Turbo Action reverse manual valvebody also in it.From the 1500 i had it idleing at it was a bang when it went into first/reverse.Ive since lowered it to 1200-1300 and its not bad at all.Just want to make sure i dont screw up the cam from too low of an idle.Its pretty much the same rpm as my last cam idled at,but that was a smaller non-roller.Thanks for your input.I appreciate it
 
megacab said:
Yeah your right about the converter.Its a Turbo Action 3800-4200 that i bought from a friend that was running it behind a 440.Havent had it on the track,and im not sure what it will foot brake to.I do know it was a tight converter.I have a Turbo Action reverse manual valvebody also in it.From the 1500 i had it idleing at it was a bang when it went into first/reverse.Ive since lowered it to 1200-1300 and its not bad at all.Just want to make sure i dont screw up the cam from too low of an idle.Its pretty much the same rpm as my last cam idled at,but that was a smaller non-roller.Thanks for your input.I appreciate it
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Dynamic will more than likely recommend a higher stall in the 5000 range or more but there converters are at higher stall but act less than (street wise) that UNTIL you nail it. Give them a call and give ALL information.. wieght of car, motor, trans, gearing etc...

What is your oil pressure at while in gear and in park/neutral?
 
Oil pressure in park cold is 80.Once it warms up it stays around 65 to 70 in park but goes back up to 8o with rpm.In gear warm(around 900)it drops to about 45 but once again climbs back up with rpm.
 
megacab said:
Oil pressure in park cold is 80.Once it warms up it stays around 65 to 70 in park but goes back up to 8o with rpm.In gear warm(around 900)it drops to about 45 but once again climbs back up with rpm.
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I just realized something this morning that I didn't notice last night(it was late). You have a roller cam so it's hard for me to see anything could happen to that cam with the oil pressure you have. Even if you drop the RPM down some more. Now I'm not a engine builder guru or anything. Send a private message to BJRracing, or moper (with a "e") and see what they say. They build race motors.
 
Thats a long stick and its gonna idle high. Some guys like to idle them higher then others. To me it sounds like your converter is to tight though.
 
Megacab I have run a few roller cams on the street . My currant cam is a bullet .668 lift , I idle it at 1300 to 1400 rpm to keep enough splash oil to the lifters rollers, but I run a 4spd no problems so far. I use 828 comp lifters(solid body)with a cross over oil tube so the lifters get all the oil they can. If you are running bushed lifter bores or have the oil gallery tubed you might want to keep the idle at 1200 or higher( put in neutral when stopped).Call Ryan and see what he recomends as we both know he is very knowlegable about these things, good luck you have one hell of an engine there.
 
I agree on the convertor. Give Lenny a call at Ultimate...He's a member here to. On the idle speed, that's a lot of spring over the nose. There would be a couple ways to address the idle oiling if it had to. But at that compression and cam choice, I'm guessing that wasn't ever talked about..lol. I only use bushings in a roller cam block but typically I would not have that much cam or compression in anything I build unless it was race only. I build street engines primarilly that sometimes race. As far as lifter oiling, they are simply splash fed by the crank's windage. I would not be too concerned with idle speed per se as the needle bearings in the rollers are not designed to be submerged in oil. However, if you street drive it you need to make some extra effort and once a year pull the valve springs and test them for tension and at least every two years have the lifters rebuilt. A few street miles can be much harder on them than several days at the track. The springs lose tension and then the lifter is allowed to bounce and then they come apart in no time. The roller must stay in constant contact with the lobe as they dont do well with bad harmonics that poor valve control and weak springs bring.
 
Thanks guys.That shed some light on it.Thanks for the compliment on the engine.The car is pretty ugly right now being its in primer,and i see alot of guys snicker at the local donut cruise lol.But id like it to run like a bat out of hell before i clean it up to much.Ryan chose the cam after doing the heads for me,although i ended up bumping the compression up after the fact.The lifter bores are not bushed,he just had a set of Chet Herbert rollers made to work in the stock bores.The cam was an afterthought.When Ryan started on the heads and found out the rest of the package,he recommended i change a few things.It seems he definately led me in the right direction,and although i spent WAY more then i had anticipated im very happy,and he gave me tons of advice.Im sure he was happy to get rid of me lol.I later saw the crossover oil mod that your talking about.Next time its down i will do that.
 
How often are you guys checking your lash on rollers?I know its good to keep up on it anyway,but how often should i be pulling the valve covers?Thanks for being patient.Never had this radical of a motor before,and i dont want to tear into it anytime soon.Im trying to make it live for awhile at 7000 rpm
 
Thanks for the info Moper.I didnt set out to build the motor this radical.Was just going to build a warmed over stock stroke 340 if you can believe that.But in a quest for that 10 sec timeslip things snowballed lol.I think with just a few changes,fuel system ect i would have had the old combo in the 10's.I hope i've cemented myself deep in the 10's by going overboard.But guess i have to realize its not a street car anymore,by the defintion of one anyway.Next motor may be a little tamer with a bottle so i can get a little more use out of it.
 
I would say run the lash twice a summer if you dont notice any changes when you check it.
On the cross over mod... it's not for the lifters at all. That mod keeps the volume up for the #4 main bearing (and therefore the rods it feeds) at high rpm. Nothing more. I was curious how you had a cam that large with the stock lifter nores...lol. I guess custom lifters would do it.
 
i have a turbo action stall too and it is real tight it has been in there for about two years and really hasnt loosened much at all
 
The crossover tube does help at high rpm but it also doesn't restrict oil to the lifters, you can still run hydralic lifters with it . Witch you can't do with the bushings and tubes. So in my thinking there is more oil to the lifters and a better shot at getting more splash oil to the rollers, just my thinking though. I have run rollers on the street with 550 to 600 pounds over the nose and luckly I have not hurt a roller yet ( broke a link bar once at the track that hurt!).
 
Guess i better look at that mod then huh.Im always stressed out about turning it 7000 rpm lol.That would have to help.Yeah Ryan had those lifters made and ground the cam on a small base circle.Seems to work fine.I thought i heard a knock for a second yesterday(I HOPE NOT!)and pulled a valve cover.What i did find is that one lifter seemed to be hung up for better lack of words.I could move it away from the valve and it would stay.So i loosened the shaft assembly and moved the rocker a little then tightnened it back down.Seems ok now.Their Harland Sharps so their not shimmed between the rockers.I hope that wont hurt the motor.I would think they wouldnt do that.
 
The reason for the mod tho, has nothing to do with the lifters. It doesnt ad any volume to either side. If youthink you have a starvation issue look at the rod bearings. You'll see signs of issues with them first.

Mega - if you have a lifter sticking in the bore you should pull it and find out why. That could become a large issue at some other inoportune moment.
 
Thanks Moper.I understand what your saying on the oiling mod.Would have been a worthwhile mod to make while i was in there.As for that lifter,its actually the rocker that was notchy.The easiest way to explain i guess would be that you know how when the valve cover is off,you can grab a rocker and rock it back and forth within the lash amount?Well on the intake rocker,#1 cylinder,i could move the rocker a bit but it wasnt a smooth fluid motion,and instead of the rocker falling back down onto the valve,it would stay raised,off the valve tip.So loosened the shaft and kinda moved it over the minute amount i could.That freed it up and it was normal.I had fired up the motor for a friend and the idle was low from us messing with it.Thought i heard a knock.Adjusted the idle and it was gone.Of course the valvetrain is a little noisy through the breathers,so maybe it was that.Im hoping.But thats what i found when i pulled the covers.
 
Ah. That makes more sense. You can also use the shim kits to help control the lateral movement in the rocker... And at some point you might want to pull that shaft and make sure there's no galling anywhere.
 
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