Engine Cylinder balance results

[08GT500]

Hi,
You want Rocker travel across the width of the Valve Stem with the Stem’s witness marks as small as possible, slightly off centered is OK if you can reach it with under
</= 0.080 is the Max. recommended Rocker tip travel across the Stem.
If you cannot reach this number, running different Rockers is the next step. Rockers of the same Ratio from different Mfg’s will measure slightly different from Stud Trunnion to Tip than others, then there’s adjustable types, (very expensive).
A slightly off-center Rocker arm tip position is OK as long as the Rocker tip’s travel across the Valve Stem is </= 0.080, maximum
A slightly off-center rocker arm tip position at half-lift is OK as long as tip travel is minimized. Where is your witness Mark at its best now? Have a pic?
The ProComps also had an issue with the Rockers not centering on the Valve Stem from left to right, requiring adjustable Guideplates. How’s your alignment that way?
Cylinder pressures should be 7-10% of each other, 18% is a bit high- but as your Rings haven’t fully seated yet, that’s likely why I’d add some oil to the Cylinders and do a Compression test once it gets in there to make a better temporary seal to see if the loss is related to a leaky Valve or Valve(s). Have you noted any excess play between the Guides and Valves (ones with the light Springs installed)?
Some resources you may wish to review..


FOR TRICKFLOW HEADS, BUT FACTS ARE THE SAME.

https://static.summitracing.com/global/images/instructions/instruction%20sheet.pdf

OPTIMAL PUSHROD LENGTH/OPTIONS.

https://static.summitracing.com/global/images/instructions/tfs-9000.pdf

Hope that helps!
-John

 

[08GT500]

Hi Rocky,
How are you making out, get a decent sweep pattern within spec’s near the Valve Stem centerline?
Sounds like you were close. About that Exhaust Valve Spring that was kicked out, was that something that may have been like that from the beginning that you might’ve missed when you first set up the Rockers...or are you pretty sure that happened after the motor ran?
In regards to a question you’d earlier asked- answered properly..An Intake Valve would’ve explained the backfire through the intake you had noticed- it’s certainly possible you may have a Valve hanging up, hard to catch by eye as it only needs be very subtle.
I think the Geometry (at least) being off played a role in that, but those Head’s have a track record of guide & alignment issues- most all Heads are assembly line produced & things aren’t as QC’d as they should be.
TrickFlow’s Rockers have proven well, BTW, I’d stay clear of Proforms.
Best!
-John
P.S. Only way to be 100% is if after this you’re still experiencing problems, pull the Heads and let a good Shop tear them down and go through them.

 

[08GT500]

Hi,
Was reviewing the Pics posted, are your Keepers purposely unlocked from the Valve Stem in this Pic you had posted earlier?

Keepers held in securely, as below.

 

[rockyracoon]

when I initially measured for pushrod geometry I used the method Scott Foxworth explains in his video and I think where I went wrong was when I took into account the threads per inch of my rocker stud I mistakenly thought I had 7/16 studs as opposed to the 3/8 studs and that was how I arrived at the 6.650 length.
I just re checked using the correct conversion of 0.42 tpi and am coming up with a 6.400 length pushrod, incidentally that is the exact length I am coming up with while using the witness mark method. so that being said at that length the sweep width is around .070" It is my understanding that different brands of rocker arms may actually reduce the sweep width, depending on the distance between the center line of the roller tip and the centerline of the trunion bearing (axle stud)

 

[rockyracoon]

No the keeper being unlocked was an oversight from the other day.
As far as the kicked out spring that could very well have been that way and gone unnoticed by myself.
Those rockers I was running are I believe elgin brand stainless not aluminum.
So I think I should come up with a way to lessen the sweep width before I reassemble.

 

[08GT500]

Hi,
IMHO, if you’re now centered and your sweep is 0.070, you could bolt it up and be just fine. There are indeed Rockers out there that do have varying distance(s) from roller tip and Trunnion centerline(s), you could also notch back a bit on the Pushrods and lose centerline slightly, and further reduce sweep.
Elgin Rockers are good quality Rockers, you could also bolt it back up to see if you’re issue is alleviated, see how things are with the Valvetrain now in order, see if your Valves function as they should, with solid geometry, see how she runs.
Best!
-John

 

[08GT500]

Hey Rocky,
Jeez, I’ve been looking back at some of my texts to you, some came out plain ....confusing!
I type something & all seems appropriate when I type it, then preview it...then I look back a day later and entire sentences are left out, characters substituted, rearranged, postings even repeat 2 or 3 times, wth? lol.
Trying a new hybrid Software, more detailed responses, hope it helps. Sorry, bro.
If something’s unclear, please let me know. Not trying to confuse!
Anyways, did you decide whether you’re going to try to reduce your valve stem sweep further, or go with the Rockers you have, pushrod length you’ve calculated and try it out?
That backfire through the intake may well have simply been due to an intake valve hanging up due to the Geometry.
Your Geometry sounds good, now. As it was corrected prior to running very long, I’d think if the Heads were made as advertised your Valve-train issues should now be a thing of the past. I’m emanating Optimism!
T.Flow stage 1 Cam with those Head’s should yield some good gains by freeing up the last restrictive components, the intake & exhaust, pull more air through..free flowing exhaust...add a little more fuel.
Not sure of your goals, see what you think of the below. Same basic build but for reference, built a 94 GT with TrickFlow 190’s Vs your 190cc Intake port, 2.02/1.60 Heads made 297HP @ 5,600 and 332Ft/Lbs at 4,400. 94’ Mustang GT. (Parts below).
No need to go totally overboard before results are undeniable. It’s Basic bolt-on’s. If I had that build, wanted to keep it reasonable, but get some well deserved gains..270-290 RWHP running ideal with a good Tune.
1) 70mm BBK Throttle Body.
2) BBK Fenderwell Conical Filter CAI.
(That’s + 25 RWHP, 30FT/Lbs on a STOCK 95 GT).
3) 1-5/8” BBK or MAC LT’s will add 15RWHP to a STOCK 95’ (and lose the “drone” sound).
4) MAC 2.5” Catted H Pipe.
5) Flowmaster American Thunder Catback exhaust. (SLP loudmouth if you want obnoxiously loud). Or, have a Muffler shop bend & Fab up a 2.5” to save $$.
6) #24lb ACCEL Injectors.***
7) Pro-M MAF for Fenderwell CAI w/Conical Filter, calibrated for #24lb injectors.
8) Aeromotive adjustable Fuel pressure regulator, Upgrade the Stock Fuel Pump with an Aeromotive, Walboro or similar with a 10 Micron inline Fuel Filter.
9) A 4 Bank SCT Chip, or a Dynotune.
10) Don’t forget 02 Sensor extensions if you decide to run Longtube Headers.
11) If that’s not enough snap, I’d consider gears...3.73’s or 4.10’s.
12) Suggest Building it equal. Want it safe to stop and handle as well as accelerate. Frame connectors aren’t imperative, but will stiffen things up. Clutch should hold out, will wear quicker. Clutch was replaced, right?
**Shorty’s alone wont yield much more HP/TQ than Stock, but if you run a decent Catted H Pipe and a high flow Catback it’ll improve overall gains over OE Manifolds. It’ll also sound better.
*** 19.5lbs injectors will support 258HP at an 85% Duty Cycle, 24 Pounder’s will support 326 HP. Don’t really want to run much above an 85% Duty Cycle, nor have to Crank your Fuel Pressure through the Ceiling to avoid a lean condition. If you decide on parts as suggested, I’d shelf the 19.5’s and run 24’s.
No reason you won’t plant 275-290HP with that Combo, maybe more. UnPorted GT-40 lower is the Cork in the bottle now, uncertain of what the upper you’re running (?).
Is this along the lines of what you’re looking for?
Best!
-John
P.S.: If this gets all confusing due to Software, I’m going to have a Conniption!