383 wont rev over 4500 rpm

[DENNYSCARS]

Hey Guys,

Would really appreciate your input and ideas on my conundrum. I have had numerous challenges with this resto as all of you can understand.  Have been working them out one by one.  However, I am stuck on this one, as is the engine builder and several other "experts" on the subject.  The cam was supposed to be degreed correctly and all parts were selected for the build.  After dumping a problem Demon carb, FBO ignition, several problems are resolved.  Now the issue is I cant rev the engine over 4500rpm (approx) without the valves floating.  Have original heads with some porting, factory HP manifolds with TTI 21/2 H-pipe exhaust, 727 auto with gear vendors attached, 2000-2500 stall, 3:55 with 26" wheels. Quick Fuel 780VS with Performer RPM.  MSD 8386 ignition, Diamond Pistons (4.310, Pt # 51903) and the following cam specs:      Race Brown Cam Specs.

            Intake      Exhaust
Duration @.050"                   220*      220*
ADV. Duration (.008)      264*      264*
Valve Lift                     .460*      .460*
Centerline         105*      115*
Lobe Separation   110*   Rocker Arm Ratio  1.5

[rt green]

does the msd have a rev limiter?

[firefighter3931]

Were the valvesprings changed to match the new cam ? Valve float is a "control" problem....not enough spring for the application. 


Ron

[Challenger340]

Were the valvesprings changed to match the new cam ? Valve float is a "control" problem....not enough spring for the application. 


Ron

BUMP !
That Cam will want minimum 100# seat pressure and 280# or so over the nose.......
That,
or you have Chinese Lifters !

[A383Wing]

agree...I say too weak of valve springs

Bryan

[DENNYSCARS]

sorry, some of the info did'nt get copied.  would it matter if the valve adjustment was off on the lifters?  if i tightened them down another 1/4 - 1/2 turn?  they currently are set at .000 + 1/4 turn.  no clicking except for startup after setting for a day. I have had a problem with the engine running better with total timing over 40*.  Runs better, no kick back on starter, more vacuum, etc.

Valve Timing @ .050" Lifter Rise
Intake     Open 5.0 BTC       Close 35.0 ABC
Exhaust    Open 45.0 BBC   Close -5.0 ATC
Lash   Hyd.   Int  .000"      Exh. .000"   
Spring Press.   Seat 100-110      Open 280-290

[DENNYSCARS]

rt green,

the distributor rev limiter is set @ 5000-5200 rpm

[Challenger340]

Just me.....but,
myself....having struggled through some Hydraulic Lifter(offshore Chinese Bodies) internal valving related problems over the last few years, I immediately tend to get "tunnelvision" when I hear about valvetrain instability over 4500rpm, so...(and I hope I am not clouding the issue for you, as it could be something totally unrelated to my problems),
But if you believe you have adequate/correct Valvespring pressure,
the next thing to check is Hydraulic lifter bleed down AFTER the Engine has been run, warmed up and Temp stabilized for a good hour.
Then,
remove the Rocker Covers and bump rotate each cylinder to TDC(both Valves Closed), by hand, press on each Rocker pair to see if any are "soft", or merely holding up on the preload simply by Lifter/Plunger pressure within the Lifter.

If you find any "soft" lifters...there is your Problem !
You my friend, are then, now a Victim of Offshore Chinese JUNK Lifters being re-boxed in anything from Lunati to CompCams to "whomevers" boxes for resale.

Your Engine, IMO,  already displays 3 partial problems symptomatic of this Chinko Lifter problem...I say "partial" only because, as I said earlier, they may also be other unrelated problems, so NOT written in stone, just worthy of further Investigation, to at least RULE OUT the Lifters.
1.) Ticking after restart(Lifter bleed down)
2.) indifference to Lifter preload at 1/4, 1/2 turn or further
3.) Runs better with a TON of spark advance because it likes igniting the LEAN mixture ONCE only,(from lack of Valve Lift in the collapsing Lifter), rather than fighting TWO flamefronts.
This problem could also be merely a spun Harmonic Balancer so it runs better at what you THINK is 40* Timing when actually lower.

Like I said, just something to "check" in your Diagnostics as you move further with this problem. 

[DENNYSCARS]

Well you may be correct ..... I just replaced the harmonic balancer and that wasn't the problem. Since several agree with the lifter and spring theory then which brand do I trust for replacement?

[Challenger340]

Well you may be correct ..... I just replaced the harmonic balancer and that wasn't the problem. Since several agree with the lifter and spring theory then which brand do I trust for replacement?

IMO,
If you are in fact confident of 100# seat pressure, and corect over the nose pressure for the Cam, try checking as described above for any Lifter bleed-down,
then,
if you wish to replace the Lifters as faulty, which they probably are if you are able to compress them after running the Engine....
contact Topline Johnson Lifter directly, to purchase U.S. Made Quality Hydraulic Lifters.

I have covered this before in other threads, but Topline Johnson are the only North American manufacturer left, still producing Hydraulic Lifters( in Muskegon Mi) for the low-run Chrysler Flat Tappet market......
The Topline-Johnson Lifters actually Work !

IMO,
EVERYBODY ELSE, and I mean EVERYBODY, no matter if it's Lunati, CompCams, Crane, or who-ever, are accessing EATON for Lifters because they are CHEAPER,
and EATON..... who do NOT find it economical to produce low numerical runs of unpopular applications, ie; BB Mopar, so are simply re-boxing the XhiangZhou Bodies for resale.

Once on the Bench....
You can spot the Chinese Offshore XhiangZhou GARBAGE Lifters upon dis-assembly, by the "Ball" type check Valve used internally...and VERY stiff spring
as opposed,
to the more Expensive "Wafer" & Guide type Valving system employed in the Topline Johnson Lifter, that regulates Oil much more effectively.

If anybody wants.....maybe I should get a photo diagnostic up as a "sticky", so people can recognize the Chinese JUNK first, BEORE they put them in their Engines ?

[firefighter3931]

rt green,

the distributor rev limiter is set @ 5000-5200 rpm

It's possible that the rev limiter is set too low. I would try resetting it to 6000 and see what happens before tearing into the engine 


Ron

[DENNYSCARS]

Thanks Ron,  l will try that since I had not thought of it.
:2thumbs:u

[cdr]

Well you may be correct ..... I just replaced the harmonic balancer and that wasn't the problem. Since several agree with the lifter and spring theory then which brand do I trust for replacement?

IMO,
If you are in fact confident of 100# seat pressure, and corect over the nose pressure for the Cam, try checking as described above for any Lifter bleed-down,
then,
if you wish to replace the Lifters as faulty, which they probably are if you are able to compress them after running the Engine....
contact Topline Johnson Lifter directly, to purchase U.S. Made Quality Hydraulic Lifters.

I have covered this before in other threads, but Topline Johnson are the only North American manufacturer left, still producing Hydraulic Lifters( in Muskegon Mi) for the low-run Chrysler Flat Tappet market......
The Topline-Johnson Lifters actually Work !

IMO,
EVERYBODY ELSE, and I mean EVERYBODY, no matter if it's Lunati, CompCams, Crane, or who-ever, are accessing EATON for Lifters because they are CHEAPER,
and EATON..... who do NOT find it economical to produce low numerical runs of unpopular applications, ie; BB Mopar, so are simply re-boxing the XhiangZhou Bodies for resale.

Once on the Bench....
You can spot the Chinese Offshore XhiangZhou GARBAGE Lifters upon dis-assembly, by the "Ball" type check Valve used internally...and VERY stiff spring
as opposed,
to the more Expensive "Wafer" & Guide type Valving system employed in the Topline Johnson Lifter, that regulates Oil much more effectively.

If anybody wants.....maybe I should get a photo diagnostic up as a "sticky", so people can recognize the Chinese JUNK first, BEORE they put them in their Engines ?

i think it should be a sticky--------lifter,thanx for the info

[john108]

Just for clarification:
Challenger340 - Do you have an opinion on solid lifter manufacturers?  Other than using those that have the EDM holes for CAM oiling?

[Challenger340]

Just for clarification:
Challenger340 - Do you have an opinion on solid lifter manufacturers?  Other than using those that have the EDM holes for CAM oiling?

The Solid Lifters, amounting to what is basically just a "chunk" of Iron with no internal Valving, have presented no problems for me....
although,
after what I have been through with the Hydraulics, and knowing what I do now, as to WHO makes WHAT and WHERE, and RE- BOXES,
as a result,
I SUPPORT American made products period, and typically Topline-Johnson Lifters made in Muskegon Mi., even for the Solids.

Look, I am in the Performance Engine Building Industry, thats WHAT I do.....
and after multiply Dyno tests,
and having to look after my Customers at GREAT expense..... because of GARBAGE Crappy Chinese hydraulic lifters......I simply can NOT afford but to support American made QUALITY, and keep those JOBS HERE !

On a personal note...
I would LOVE to start manufacturing defective Chop-Sticks here, and SHIP them over there and flood their market for PAYBACK...see how they like it.

[john108]

Challenger340-
Thank you

[cdr]

Just for clarification:
Challenger340 - Do you have an opinion on solid lifter manufacturers?  Other than using those that have the EDM holes for CAM oiling?

The Solid Lifters, amounting to what is basically just a "chunk" of Iron with no internal Valving, have presented no problems for me....
although,
after what I have been through with the Hydraulics, and knowing what I do now, as to WHO makes WHAT and WHERE, and RE- BOXES,
as a result,
I SUPPORT American made products period, and typically Topline-Johnson Lifters made in Muskegon Mi., even for the Solids.

Look, I am in the Performance Engine Building Industry, thats WHAT I do.....
and after multiply Dyno tests,
and having to look after my Customers at GREAT expense..... because of GARBAGE Crappy Chinese hydraulic lifters......I simply can NOT afford but to support American made QUALITY, and keep those JOBS HERE !

On a personal note...
I would LOVE to start manufacturing defective Chop-Sticks here, and SHIP them over there and flood their market for PAYBACK...see how they like it.

now i like that idea-----------im in the auto repair business & parts quality is really bad,almost everything is made in chinchena,even some oem stuff  nothin like refixing stuff for free because of defective chinchena parts,and an upset customer & i really hate that

[Brass]

Just for clarification:
Challenger340 - Do you have an opinion on solid lifter manufacturers?  Other than using those that have the EDM holes for CAM oiling?

The Solid Lifters, amounting to what is basically just a "chunk" of Iron with no internal Valving, have presented no problems for me....
although,
after what I have been through with the Hydraulics, and knowing what I do now, as to WHO makes WHAT and WHERE, and RE- BOXES,
as a result,
I SUPPORT American made products period, and typically Topline-Johnson Lifters made in Muskegon Mi., even for the Solids.

Look, I am in the Performance Engine Building Industry, thats WHAT I do.....
and after multiply Dyno tests,
and having to look after my Customers at GREAT expense..... because of GARBAGE Crappy Chinese hydraulic lifters......I simply can NOT afford but to support American made QUALITY, and keep those JOBS HERE !

On a personal note...
I would LOVE to start manufacturing defective Chop-Sticks here, and SHIP them over there and flood their market for PAYBACK...see how they like it.

So after reading comments like this about Chinese lifters, I had to ask Crower (twice) where theirs are made because that's what I have in my car.  They said the USA but didn't elaborate...  hope its true.  Just FYI.

[rt green]

 

[DENNYSCARS]

OK,  Ron, I changed the setting on the tach and it solved the 4500 RPM issue.  It at least will run thru the gearvendors without "floating".  Shifts around 5K from first to first OD.  Have the tach set at 6500 now.  Still have the bleed down of the lifters. 2-3 hours at a car show and on start up it will clack for a few.  I am going to have the springs checked and most probably will replace the lifters.  Thanks alot for everyones of your input.  I once again have learned....  I still have a question,  what if the cam was not degreed correctly?  What would the result be?   

[mauve66]

when guaging the rpm level i'm assuming you are using the factory tach, i've always thought them to be unreliable, it would be nice to know what the rpm REALLY is so you know if the rev limiter is working right or not.

[rt green]

so it was a rev limiting problem

[Chryco Psycho]

if the cam is advanced a few degrees it will add lower rpm power reverse if the cam is retarded a few degrees

[firefighter3931]

OK,  Ron, I changed the setting on the tach and it solved the 4500 RPM issue.  It at least will run thru the gearvendors without "floating".  Shifts around 5K from first to first OD.  Have the tach set at 6500 now.  Still have the bleed down of the lifters. 2-3 hours at a car show and on start up it will clack for a few.  I am going to have the springs checked and most probably will replace the lifters.  Thanks alot for everyones of your input.  I once again have learned....  I still have a question,  what if the cam was not degreed correctly?  What would the result be?   

Cool....that was an easy fix 

As far as the lifters bleeding down....that's not a huge issue as long as they pump back up shortly after startup. Most hyd lifters will become unstable at 5800-6000 rpm but if your combo (cam/heads/intake/carb etc...) are maxed out anyway then why bother ? As long as the valves aren't floating at high rpm and you can live with the minor annoyance of a little noise on startup then my suggestion would be to leave it alone. 

if the cam is advanced a few degrees it will add lower rpm power reverse if the cam is retarded a few degrees

Exactly...advancing the intake centerline moves the powerband slightly lower.....the opposite effect if the ICL is retarded.



Ron

[DENNYSCARS]

Yes the "floating issue" appears to have been the rev limiter.....Thanks again for all of your help. 

Ron, if the ICL was setup retarded, can it be compensated by "over advancing" the timing to get the powerband better at lower rpm?  or...................?

[firefighter3931]

 
Ron, if the ICL was setup retarded, can it be compensated by "over advancing" the timing to get the powerband better at lower rpm?  or...................?

The only way to adjust the powerband is with cam timing. Advancing the ignition timing is sometimes beneficial if the engine combination wants increased spark lead but that in itself won't alter the effective operating range of the engine....but it can make the engine feel stronger/more responsive off idle. 


Ron