Breaking up

turbo nasty said:
Considered that as well but the cost of 12 new rockers will be more money than all the springs and such. A real pisser that the heads arent assembled with the right springs when the cam specs are given.
Click to expand...

That is the reason I have a digital valve spring checker myself for my 2 eye balls can see and not rely getting someone else to do it for me , not many people will take pains to set the springs like they are supposed to do and forget this is Turbo Buick not a Chevy NA engine .

Putting a smaller ratio rocker will have to help also and it may be enough to fix it
 
turbo nasty said:
Considered that as well but the cost of 12 new rockers will be more money than all the springs and such. A real pisser that the heads arent assembled with the right springs when the cam specs are given.
Click to expand...
I will talk to Nick and see if we cant work something out. He has been great to deal with and I really think if this idea works, he will understand.
 
TT/Ameasap said:
I will talk to Nick and see if we cant work something out. He has been great to deal with and I really think if this idea works, he will understand.
Click to expand...

I spoke with Nick a few weeks ago during a SoCal Buick event. He confirmed that 170 lbs on the seat is required for higher RPM with the TA heads. They are setup very conservative.
 
I went 1.55 rockers and shimed my valves .060. I have no problem turning 5600 rpms at 23 psi. I was fortunate to catch it before the heads went on.
 
TurboTdr3.8 said:
That is the reason I have a digital valve spring checker myself for my 2 eye balls can see and not rely getting someone else to do it for me , not many people will take pains to set the springs like they are supposed to do and forget this is Turbo Buick not a Chevy NA engine .

Putting a smaller ratio rocker will have to help also and it may be enough to fix it
Click to expand...
NA Chevy engines have the same or more spring requirement than a Buick typically. Most of the old timers that race NA Chevy engines are light years ahead of most on this forum regarding valvetrain setup for stability. Instead we end up with endless threads like this one where people that are having valvetrain stability problems are questioning known information that's provided and been researched and proven. For those we will let them think that 150lbs seat and 375 open is enough for aggressive cam lobes and they can continue posting about how their car with 9 sec parts runs 11's. Imo if someone is buying/installing a given cam they should be able to determine what springs they need based on the measured data they acquired. Meaning given a cam with no lobe data,
Measuring it, determining what it is, choosing springs that will work at the height they have to work with, actually perform the setup, determine correct pushrod length and type (it sure isn't 5/16 for an aggressive lobe), mock all parts up, check all clearances, etc.
If any of these things are in question then the individual is way better off paying someone to properly do the work. People who do this kind of work document everything and know exactly what they did. This way if problems come up they can at least back up their questions with known before data and have something to go off of.


Sent from my iPhone using Tapatalk
 
Agreed on all accept needing more than a 5/16 push rod. I run a 5/16 80 wall in my small block stroker Mopar solid lifter motor. Way more spring pressure and a solid lifter profile roller cam with zero issues at 7200 rpm. That push rod will support 600# open pressure.
 
BARRACUDA1968 said:
Agreed on all accept needing more than a 5/16 push rod. I run a 5/16 80 wall in my small block stroker Mopar solid lifter motor. Way more spring pressure and a solid lifter profile roller cam with zero issues at 7200 rpm. That push rod will support 600# open pressure.
Click to expand...
The spintron doesn't lie. I used to run 5/16 pushrods on everything also long ago but have been using 3/8 pushrods in any aggressive lobe application. I personally would not run a 5/16 pushrod over 450lbs open pressure with an aggressive lobe. They may not be needed at that level but they sure aren't hurting anything. Fwiw solid lifter profiles are usually less aggressive than hyd roller cams. From what we've analyzed the most aggressive hyd roller lobes like the XFI family and the 3188 and up XE lobes are as aggressive as a TK lobe which is about the most aggressive out there. The hydraulic lifter is a big cushion. The solids are also lazy in the lash area (for good reason). Without enough lash they can really hurt performance.


Sent from my iPhone using Tapatalk
 
I have a TA Performance aluminum engine I purchased used. The spec for the springs are 550lbs open on a solid roller. Not only are the 5/16" pushrods rubbing on certain holes, but they are all warped from deflection.
 
forcefed3.8's said:
I have a TA Performance aluminum engine I purchased used. The spec for the springs are 550lbs open on a solid roller. Not only are the 5/16" pushrods rubbing on certain holes, but they are all warped from deflection.
Click to expand...
The exhaust opening on a hard running turbo engine is brutal. Opening against a lot of pressure


Sent from my iPhone using Tapatalk
 
The aggressive profile and ramp (lobe) speed of a roller cam also has its drawbacks. A higher lift and faster ramp speed needs stiffer valve springs. Stiffer springs also increase the load on the push rods, so heavy duty push rods are needed. High lift cams add more movement and friction to the rocker arms, so roller rockers are pretty much a must. Just like Newton's law, for every action, there is a reaction, engines are the same way. Increase the load in one place and you'll surely increase the load (or friction) in other places.
 
I see that morel makes a short travel lifter now. My current ones are the regular morels and IIRC they are not supposed to be ran at more 350 or 400 lbs spring psi and now that I will stepping up the spring psi to over 500 over the nose are these rates ok for the Short travels?
 
The PAC1203 is a 1.25" dia spring. It has an inner spring not just a dampner, so it requires a special retainer. It might not fit over the .531 guide seals, i am not sure, Bison has experience with these springs. I use a 1.55 spring on my aluminum heads.
 
Last edited:
Ok guys.
I checked my installed height and got 1.825
Tested the old spring combo with inner springs on a high tech digital spring machine from a race engine shop.
Old combo = 155# and 390#
New TA inner springs with same valve spring tested at 190# and 460#

Is this too much for a hydraulic roller cam? 853 lifters? or 5/16" push rods?
 
Last edited:
You must log in or register to reply here.

Similar threads

T
No start no spark no inj pulse
Replies
3
Views
289
BEATAV8
BEATAV8
S
can't get past 5psi
Replies
18
Views
1K
shmed
S
H
GREMLIN CONTINUES TO BE PRESENT MAKING DRIVING UNSAFE
Replies
15
Views
607
MikeS
M
G
High BLM
Replies
7
Views
1K
GNVAIR
G
C
TR6 problem.
Replies
3
Views
686
Clark6
C
Top