Engine Cylinder balance results

Hi,
Rocky, new build? Didn’t know it was new.
Geez, to me vacuum seems low for that Cam. Stage 1 TF, correct?I’d expect 15 on the low side..see more like 17 or 18 in that healthy a motor.
Just FYI..Rings should be seated under varying loads while driving, realize things look good with compression- but they really need some good varying load lugging to seat for the long run.
How many miles (or hours) on this new build?
Did you run this Cam straight up, was it degrees in?
Did you retorque your lower intake? Just make a torque wrench pass over them & check- engine cold.
Has any tuning been performed?
Valve lash settings, I’d start there. You mentioned hearing valve-train noise. May have one Intake valve a tad tight or less likely sticky.
Best!
John

Hey Rocky,
You could take 2 near identical 95’ GT’s and modify the same as you have, one may run well with no Tune, other may not. As Kurt mentioned, it’ll need a Tune to perform best, but any possible issues first need be identified and repaired prior to Tuning.
Over time I‘ve found associating engine Vacuum numbers with a solid RPM gives more consistent results, I use 1,000RPM’s.
-For modified motors untuned, or with issues it’s more realistic an RPM a finicky motor will tend to agree to run stable at for certain testing, has helped.
Since I do top ends on all Mfg’s frequently, I’ve logged the numbers of most TF parts.
As you’re not new to all this, I’m just trying to establish exactly what the build is, there’s things you’ll already know, I’m just suggesting where I’d start, what direction I’d go...
-Which ProComp head’s are you running?
-And, what’s your Vacuum at 1,000RPM’s?
I’d suggested that possibility of preload being tight on a Cyl, as you mentioned hearing a Tap, and an intake backfire under load. That would be where I’d start, pull the covers and run through the cylinders & move on once you confirm as correct.
Check #1 Piston and Balancer’s lineup @ TDC to rule out any timing issue. Sounds as if it’s OK, but easy to confirm.
Keep lash more on the conservative side, as your chasing this, at 025-.040.(1/2-2/3 turn past zero lash & lock). Norm.is pushrod .020-.060 into the lifer after zero lash.
You won’t always see a slightly tight lash setting affect numbers in a cold compression test, but you’ll feel it engine hot.
No Wideband yet? Have faith in reading your spark plug electrodes for now, they won’t lie.
Motor was running OK before the rebuild, no
Systemic issues, just tired?
I’m uncertain if you’re relying on the stock Oil Pressure Gauge, or aftermarket..It’s absolutely in your best interest & a very well spent 25-30$ if you buy a Mech Gauge to run on a fresh motor..
Still running conventional motor oil for the Ring & bearing break in? Running a High Volume or High Pressure oil Pump of type, both HV/HP...or OE? ARP Pump Drive?
Oil pressure, Cold?..Operating Temp?

Where does the car idle, does it hunt at all?
Is the IACV, TPS set, you adjustEd idle up manually?
I’d be looking at your spark output via spark tester on each cylinder, see how far a gap you can get a spark to jump & see if the others can repeat the same, try it SPOUT in & out, sometimes it has an impact if the PIP’s loose, or on its way out. Usually Injectors are affected first, not always..
Is your Dizzy stabbed correct for proper Injector timing?
When your fresh Engine Mechanical basics are all correct, your new parts functional & become exhausted, keep in mind to view it as you would if troubleshooting any other 86’-95’ Mustang GT, vacuum lines, grounds, Alternator output, aftermarket ignition component avoidance, and all the other basics.
Also consider how the R&R of the engine may wreak havoc on the wiring, connections disturbed and sometimes less than optimal when reterminated, etc.
Build questions, etc.. to get on the same page?
1) Drain your Tank & full up with fresh fuel? If not, how long has the fuel your running been in your tank?
**2) Are you running the Cam’s springs, retainers...did the Shop tear down the heads & check guides, seats, etc, pressure test?
3) Exactly what’s been added to the build, car wasn’t bone stock previously-correct? 3B)Already running a rechipped EEC before the build (you mentioned a deleted Smog item).(?) What injectors, MAF, TB, other Mod’s are you running? Headers? Shorty’s, LT’s?
4) You did verify fuel pressure, also perform a Volume test? You‘ll then know it can keep up during heavy engine demand.
5) Most Smog still intact, are you running an aftermarket exhaust, Cat’s? Mentioned new 02 sensors enroute, improvement?
6) Check all the new Injector connectors you added, add AD grease to improve connections, tested all for correct Voltage at all injectors & presence of pulse.
7) Have you tried Clocking the MAF a bit to see if you can get an improvement in running conditions? Unplug it & the motor should really fall on its face..
8) Been checking the EEC for trouble codes right along?
9) I’d expect the Car to run decent with the parts you’ve mentioned, uncertain what your ProComp head’s have for Chambers, and your resultant C.Ratio. .040 thick Gaskets?
Hopefully, this will get you moving and the questions answered will help to narrow things down.
Best of luck Rocky!
Enjoy the weekend!!
Best! -John
** ProComp head’s, in my own experience, are head’s that should be carefully checked out before using. I’m not saying other’s are exempt from this, the days are over where you can bolt up 95% of new head’s & have certainty they’ll work as desired.

rockyracoon said:

John here is the specs on my cylinder heads. evidently they are not pro comp but the vendors own castings.

These heads feature closed style 64cc combustion chambers and 190cc intake runners. In addition to the nearly 40lb weight savings these heads offer over factory cast iron heads, they will yield about a 55hp gain over stock E7TE castings. In unported form these heads will support 500+ horsepower on pump gas. If you are looking for a race grade head that is comparable to Edelbrock, Dart, Trick Flow and AFR at a fraction of the price look no farther then these.These heads are machined and assembled by us, they work great on Carburetor and fuel injection applications!! The features of these are as follows:

Heads are pressure cast from premium quality 2024 aluminum alloy. Unlike many inexpensive aftermarket heads that are sand cast these are cast in steel permanent type molds. This offers a stronger more durable cylinder head with consistent thickness throughout. These castings incorporate .400 thick deck surfaces for maximum head gasket longevity. If you are running nitrous or a supercharger and have had problems with blown head gaskets and stock heads the thicker surfaces will virtually eliminate this problem.
After machining the heads have magneese bronze valve guides installed along with stellite valve seats. This is the best available combination for street use with unleaded gas. If you are racing the stellite valve seats offer much longer seat life then most competitors ductile iron valve seats
Both the intake and the exhaust incorporate three angle valve seats to maximize both low and medium lift flow.
The heads come fully assembled with 2.02 1 piece stainless steel intake valves and 1.60 exhaust valves. These valves Qual cast severe duty 1 piece stainless steel polished valves and undercut stems. These heads require NO extra knotching or relieving for piston clearencing with stock or af

So im going to go back and check the rocker arm geometry just to make sure I measured for the hardened push rods correctly.the ones I installed are 6.650" considerably longer than the stocker pushrods however the tfs stage 1 cam does have a a reduced base circle.

I have ran both koeo and koer with no codes that would be relevant to my issue.
Yes still relying on the stock oil pressure gauge, using conventional oil for breakin, electrodes are all good in visual inspection, car does hunt at idle, I will try some of the other things you suggested after I recheck the push rod geometry. the car was in fact bone stock before, heads were brand new so havel the machinist look at them, injectors are stock 19 pounders, all sensors are stock, stock headers and exhaust. no ch

one other thing of note is the fact that the exhaust exiting the tailpipes is super hot to the point that it would burn your hand if you kept it there for more than 5 or 10 seconds, thats another reason why I think it is running lean. the engine miss is present at all rpms and is present in open loop as well as closed loop although the engine does tend to run even worse (if thats possible) once it gets up to operating temperature.

I just checked one of the the pushrods coloring in the stem with a dry erase marker and it appears the mark on the valve stem is about 3/4 of the way towards the intake manifold (not perfectly in the middle of the stem) but the width of the sweep looks good right around fifty thousandth. That was not the method I originally used to measure for the proper length as my initial check for correct length was measured strictly by geometry however it appears this is how most guys are doing it. It is my understanding that being exactly in the middle of the stem is not as important as the width of the sweep.

Click to expand...

Hi Rocky,
These heads I’m not familiar width, but is a good idea to have them torn down before install, even moreso new. Pushrods too short valve sweep runs inboard, too long, valve sweep runs outboard. Yours sound short. Optimally,
Every new Cam should be degreed in and P/V & pushrod length should all be done together, collectively.
An adjustable pushrod, 2 solid roller lifters, light checker springs, Degree wheel kit and you’re good to go.
Since you’re all together, you can check your pushrod length in a different fashion. Be happy to run through it with you. First..
Rockers Pedestal Mount? Unless misread, I didn’t see screw-in studs listed, and pushrods seem short for stud Rockers- which vaguely are in the 7.5” range for these motors, Pedestal’s about 6.7”..
The rockers sweep path should be equally distributed across either side of the valve stem centerline to reduce any side loading wear of the guide(s), maintaining as narrow a roller tip path as possible, maximum of 0.080 or less. I shoot for 0.060 max.
If one needs to be traded for the benefit of the other, run a wider path, but keep it centered equally. Roller tip also centered laterally (left-right) ?
Excess heat means running lean, advanced timing, clogged Cat(s), obstructed exhaust, etc.
The flow increase efforts to gain performance by the H/C/I swap are being bottlenecked by some of the stock components, like the exhaust, air intake, etc.
Once the valve train’s buttoned up, it’ll be easier to move forward.
Any questions, please post!
Best!
John
P.S.: You lost a few Compression tenths with these head’s, no biggie.
Note- Saw the edit you’d made, just now. Going to run an adjustable pushrod with a checker spring installed from the top?