Hydraulic Roller Lifter - Problem adjusting Preload - Chevy Nova Forum
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Old 5th-November-2007, 11:26 AM   #1
66german
 
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Hydraulic Roller Lifter - Problem adjusting Preload

Hi there,

now, I have a strange problem when adjusting the preload on my hydraulic roller lifters (CompCam Pro Magnum).
Switched from a solid roller cam to a hydraulic roller cam (well, and changed the lifters and pushrods, of course!).
When I do the correct procedure as according to the spec on the Comp Website (http://www.compcams.com/Technical/FAQ/FAQLifters2.asp), some of the lifters (appr. 12) have the feel I know from adjusting the preload from all my other engines, which is after you set preload in 1/8 turn I can still depress the rocker and pushrod and it will bump up again - some other lifters (appr. 4) seem to be just rock-hard and I cannot depress them like the others! The engine will not start but bark out of the carb, as I assume some valves are open (most probably from those lifters that cannot be depressed - but this is an assumption only!).
Now, I loosened up on those lifters, started the engine. It would start, but run terribly noisy, as with too much lash - which seems just logical.

What is happening there? Any suggestions?

Some engine data:
434 Motown Block / Ohio crankshaft assembly
Jegs 220 Heads with offset rockers, stud girdles
26918 Beehive Springs
CompCams extreme energy cam (248°/254° .562 .580 LSA 110°, ground on small base circle)
CompCams proMagnum hydr Roller Lifters
TFS pushrods (length checked)
Super Victor intake
Demon Carb

Greets,

Boris
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Old 5th-November-2007, 11:42 AM   #2
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I dont understand your method I guess. I spin the pushrod freely as im tightening, as soon as you feel the slightest anything, Just barely any resistance, the faintest change. then 1/2 turn and your done. All hyd cams are like this flat tappen or roller. Ive done this probably a hundred times and never had to go back through at all.
Just make sure your doing them in the correct order. Chilton manual has the order listed. You adjust half while #1 is on TDC and then spin it to #6 is on TDC (firing) timing mark on zero. then adjust the rest.

It is normal for you to still be able to press them in untill they fill with oil.
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Old 5th-November-2007, 11:56 AM   #3
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Because most of the aftermarket cams have quite a bit more overlap and totally different valve timing events than the older stock grinds, I use the Int valve open (adjust Exh valve), Exh valve opening (adj Int valve) method. It usually takes a few bumps of the motor to get them all done but once they're done they're right and I don't have this problem.
This problem is especially apparent on the more aggressive SFT and solid and roller profiles because of the first (take-up) part of the lobe profile starting in a bit sooner.
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Old 5th-November-2007, 12:07 PM   #4
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@Pwrtrip75:

Concerning the "feel": I am 100% sure about the general mechanical order. Did the procedure exactly like you stated, but used D-man's approach concerning determining which valve is on base circle (it is also in the Comp specs for the adjustment procedure - see this link: http://www.compcams.com/Technical/In.../COMP4-115.pdf). I just did only 1/8 turn according to CompCams paper instead of your 1/2 turn. And then 12 lifters can still be depressed, 4 cannot - they are hard and won`t give in...

@D-man:

Thanks for the explanation - I always wondered why, so now I know!

Greets,
Boris
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Old 5th-November-2007, 12:18 PM   #5
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You might go back and check those 4 that the plunger in the lifter was "hung" in. Since you backed them out and basically gave them some lash and started the motor, you may have pounded them into submission. and freed up the hydraulic plunger. It might be worth a call to Comp also. They may replace those lifters for you if they think there's something wrong with them.
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Old 5th-November-2007, 12:49 PM   #6
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Hydraulic lifters depend on oil inside them to keep them from collapsing. If you haven't fired the motor and pumped oil inside the lifters, you may experience some 'soft' lifters. When you are tightening the lash, don't depend on the feel of the pushrod as you rotate it, depend on the lash on the valve end. Using the ICEO method, loosen the adjustment until the rocker flops around easily, then tighten the adjustment until the lash is zero at the valve end. Then tighten it your 1/8 turn and you're good to go. The lifters might rattle a little when you first fire the engine because they aren't oiled up yet, but that should subside rather quickly.
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Old 5th-November-2007, 01:09 PM   #7
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Thanks again for the input, folks.

Additional info: the lifters were used, but ran OK when we pulled them from the other motor. Haven´t been used very long, anyway. I might add, I set preload on that engine a while ago with the very same lifters without any problems.

@Mike
Quote:
Then tighten it your 1/8 turn and you're good to go.
THAT is exactly what I thought - but then the motor just won`t fire up because it backfires like hell...
A colleague suggested to set preload just normal, NOT start the motor, take spark plugs out, rotate via starter some time (to have the lifters on their usual oil pressure level) and check again.
I might just do that (though taking the plugs out really sucks with Headers in an Nova!).

Greets,

Boris
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Old 5th-November-2007, 01:12 PM   #8
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@D-man:

You really think they are gone? I just lossened them up so that they were not depressing the plunger anymore. Must be something like +0.001" or so...


Greets,

Boris
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Old 5th-November-2007, 01:45 PM   #9
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Is the cam you have compatable to go from solids to hydraulic rollers? I was considering going to hydraulics in my engine but decided to stay with solids just to be safe.
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Old 5th-November-2007, 01:55 PM   #10
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Quote:
Originally Posted by 66german View Post
@Mike

THAT is exactly what I thought - but then the motor just won`t fire up because it backfires like hell...
Are you sure you don't have other problems? Ignition, timing, firing order, carb, vacuum leak, etc?
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Old 5th-November-2007, 03:01 PM   #11
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Quote:
Originally Posted by 66german View Post
@D-man:

You really think they are gone? I just lossened them up so that they were not depressing the plunger anymore. Must be something like +0.001" or so...


Greets,

Boris
If they were actually "Lashed" at .001" you wouldn't hear them... If they are collapsed or the plunger is galled or froze then yes, they may need to be sent back to Comp for a rebuild. Then the question comes as to how they were stored.. I always submerge roller lifters in clean tranny fluid for any storage period. I've also dealt with other builders who did this right before assembly because the trans fluid penetrates quite a bit more than just motor oil for a more thorough lube.
I would also (like Mike said) check and make sure there isn't another problem showing it's ugly face just to throw you off...

BigAl713
There are a few of the milder solid roller profiles that you can run hydraulics on, but you need to check with the cam manufacturer to make sure of it. There is a definite difference in the "Take-up" part of the ramps between a hydraulic and solid profile!!
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Old 5th-November-2007, 04:58 PM   #12
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@BigAl:

I did not just change the lifters - changed Lifters, Cam, Pushrods altogether.

@Mike:
Quote:
Are you sure you don't have other problems? Ignition, timing, firing order, carb, vacuum leak, etc?
I can rule that out - engine ran very well before that and I used the same accessories/components with the same settings.

@D-man:
Maybe I have to pull the intake again and check.

Greets,

Boris
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Old 5th-November-2007, 05:01 PM   #13
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Check the firing order.
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Old 5th-November-2007, 05:15 PM   #14
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Quote:
Originally Posted by 66german View Post
@BigAl:

I did not just change the lifters - changed Lifters, Cam, Pushrods altogether.

@Mike:

I can rule that out - engine ran very well before that and I used the same accessories/components with the same settings.

@D-man:
Maybe I have to pull the intake again and check.

Greets,

Boris
You changed the cam, lifters and pushrods without disturbing the intake manifold, distributor or carburetor? I've always found it necessary to remove the distributor before I remove the intake before I can get the lifters out.
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Old 6th-November-2007, 05:32 AM   #15
66german
 
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@Mike:

Maybe I didn´t explain it well in the beginning, so here I try again:

My 434 SB was running strong on the race track with the old setup which consisted of a mechanical roller cam, related lifters and pushrods. I just wanted to have a less noisy and edgy engine for the street now, so I swapped in a hydraulic roller cam, hydraulic roller lifters but new pushrods (had to have a different length) from another 427 SB which was at that time also running strong, but was in the shop for a general rebuild.
For that reason, I pulled the complete intake of the 434 (together with the distributor, which was marked accordingly) and swapped the parts stated above. Put everything together again.
So far so good. Maybe I should explain that I am not a newbie to that kind of work - did rebuild, bring to live and race many engines, so I know a thing or two about it (like correct lash, timing etc.).
But now this interesting problem began - please read first post.

So in conclusion: I am absolutely sure that the timing, firing order etc. is correct here. I just never did experience such a problem when setting preload on hydraulic lifters...

Interesteingly, there seems to be someone else experiencing the same problem with the same lifters - please read here (I know it's long, but maybe you just read the posts by hotrodf1):

http://www.hotrodders.com/forum/hyd-...ms-123152.html

Greets,

Boris
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