Author Topic: SBF valvetrain grief - Help needed please!  (Read 1303 times)

0 Members and 1 Guest are viewing this topic.

Kevin66

  • Jr. Member
  • **
  • Posts: 45
    • View Profile
SBF valvetrain grief - Help needed please!
« on: August 18, 2025, 06:23:42 PM »
I recently assembled a new engine for my brother's '66 Comet. ALL parts were new.
   - Ford Racing M-6009-363  363 cid crated shortblock, 4.125" X 3.40", with Mahle forged flat top pistons with generous valve reliefs
   - Flo Tek 185cc 'Thumper' CNC ported aluminum heads w/ 2.02"/1.6" s.s. valves (rated flow = 278 cfm Int & 182 cfm Exh @ .600" lift)
   - Ford Racing M-6051-R351 head gaskets and M-6014-BOSS ARP head studs
   - Lunati Voodoo VDSF-282 hydraulic roller cam (231°/239° @ .050", .581"/.587" lift, 110° LSA); Rollmaster billet roller timing set; Installed @ 109.5° Int C/L
   - Edelbrock Performer RPM Air Gap intake manifold (professionally ported by Joe Crane)
   - Quick Fuel 650 cfm SS-series carburetor
   - Jegs #20990 1.6 ratio 3/8" stud aluminum roller rockers; Jegs #20277 6.248" pushrods
   - Boss 302 6-quart oil pan & 5/8" tube pickup, Melling Hi-Volume oil pump, ARP drive shaft, Comp 10W-30 Break-In oil
   - Patriot 'Clipster' shorty headers
   - Pertronix billet electronic distributor, Ford Racing 8.2mm wires, Autolite AR3932 spark plugs gapped at .035"

The engine was carefully assembled, with everything torqued to specs, and the cam degreed per Lunati's specs. The cylinder heads had been originally set-up by the factory for flat tappet use, so the springs, retainers and keepers were replaced with Trick Flow PAC dual springs (16315-16), Chromoly steel retainers (51400423) and hardened keepers (51400444) for use with the HR cam. The adjustable guide plates were maneuvered to get the rocker roller tips aligned on the valve stems.

When installed and fired, the engine started instantly and ran well. Pressures, temperature and leaks were checked. The initial timing was set at 16° BTC. The car was then taken for a drive of about 18 miles, and there were no issues with the engine's operation. RPMs were kept below 3,000. The exhaust had been cobbled together with 2.5" stubs, 20° & 45° bends to mate up with the previous dual exhaust system until the car could get booked into a muffler shop for a complete new exhaust system. There were leaks from the ball & socket collector flanges, so the head pipes were removed and re-positioned. NOTHING else was changed.

On the next run, there was only a minor leak from the passenger side exhaust, so another drive was attempted. Within half a mile there was a loud backfire, and the engine began running poorly. It did not want to rev-up, and had little power. It backfired several more times.

On examination, we found that the #7 exhaust rocker arm had broken in two down around the trunnion, with the polylock nut seized in its slot. The pushrod was bent. Any is not good, but it wasn't excessive. We checked the other rockers and all appeared to be still adjusted properly, except for the #2 exhaust rocker, which now had a slight amount of valve lash. We couldn't see anything amiss, so it was readjusted to zero lash plus one turn. A compression test was done, with all cylinders falling between 152-162 psi, so there were apparently no bent valves. The engine started fine, and again the car was taken out on the road...only to return within two minutes, farting and popping. This time, that #2 exhaust rocker arm was broken.

All of the rocker arms, pushrods and studs were then removed. What we found was that the ball on the lifter end of that #2 exhaust pushrod had broken off, and the end of the pushrod was badly mushroomed. Four of the other pushrods were now bent. Four of the other rocker arms had trunnions that would only rotate with a good effort, not freely as they should have.

The intake manifold was removed to attempt to locate the missing pushrod ball, and it was found sitting in the valley beside the lifter boss. And it was now found that the #7 exhaust lifter had a chip out of the upper rim, and that the snap ring had popped up from its groove, but luckily not gone anywhere. At this point we stopped work, unable to explain what was happening, and why?? The engine had been rotated dozens of times by hand for valve adjustment prior to startup. There was no interference that could be felt then, so what had changed?

If you've gotten this far, you know that I'm perplexed and frustrated. I could really use some help from those of you with engine building experience. What did I miss? What should I check?

Thanks for your time!



 

"In theory, theory and reality are the same. In reality, they are not!"

My427stang

  • Hero Member
  • *****
  • Posts: 4202
    • View Profile
Re: SBF valvetrain grief - Help needed please!
« Reply #1 on: August 19, 2025, 06:31:12 AM »
First I would ask how you are adjusting them, EOIC method?  Only checking to make sure you don't have the exhaust loose and spitting pushrods

Second, what is your installed height for the springs?  They list as 1.100 bind, that means if you want .080 away, 1.180 + lift .587, you need 1.78 installed height.  However, I check every spring for coil bind, and sometimes you can be slightly higher.  I looked at the FT springs and they are at 1.800 but the HR version is at 1.7500, depending how you shimmed your springs, also spec'd at 1.750 from Trick Flow, you could be right at the edge

Third, look at the cam card and make sure your lobe lift multiplied by 1.6 is what you are figuring for valve lift.  If the cam was planned for less rocker you could have more lift than planned.

Last, did you check clearance with clay and a solid roller at assembly?

It does seem that the exhaust is the issue, and it is the higher lift lobe, so I would start there



---------------------------------
Ross
Bullock's Power Service, LLC
- 70 Fastback Mustang, 489 cid FE, Victor, SEFI, Erson SFT cam, TKO-600 5 speed, 4.11 9 inch.
- 71 F100 shortbed 4x4, 461 cid FE, headers, Victor Pro-flo EFI, Comp Custom HFT cam, 3.50 9 inch

blykins

  • Hero Member
  • *****
  • Posts: 5132
    • View Profile
    • Lykins Motorsports
Re: SBF valvetrain grief - Help needed please!
« Reply #2 on: August 19, 2025, 10:32:01 AM »
Things I'd look at:  cheap rockers, cheap pushrods, no coil bind clearance, retainer hitting valve seal/valve guide, pushrod hitting rocker arm, rocker trunnion hitting the radius on the rocker stud....
Brent Lykins
Lykins Motorsports
Custom FE Street, Drag Race, Road Race, and Pulling Truck Engines
Custom Roller & Flat Tappet Camshafts
www.lykinsmotorsports.com
brent@lykinsmotorsports.com
www.customfordcams.com
502-759-1431
Instagram:  brentlykinsmotorsports
YouTube:  Lykins Motorsports

Joe-JDC

  • Hero Member
  • *****
  • Posts: 1573
  • Truth stands on its own merit.
    • View Profile
Re: SBF valvetrain grief - Help needed please!
« Reply #3 on: August 19, 2025, 08:17:50 PM »
If you drove it 18 miles without an issue, and then after sitting for a bit and starting it up again it developed a problem immediately, I would look at valve guide clearances.  Especially if only exhaust rockers or pushrods.  JMO, but look at that, also.  What is that white substance in the intake ports?  Thread sealer for the studs?  Make sure you remove that before installing the intake next time.   Joe-JDC
Joe-JDC '70GT-500

427Fastback

  • Hero Member
  • *****
  • Posts: 616
    • View Profile
Re: SBF valvetrain grief - Help needed please!
« Reply #4 on: August 19, 2025, 09:16:31 PM »
Pic says rockers are all adjusted.. Whats up with #7 cyl. Jam nut is almost flush and all the others are 3 or 4 threads down..
I agree with Joe....could be grabbing valves..     Cory
1968 Mustang Fastback...427 MR 5spd (owned since 1977)
1967 Mustang coupe...Trans Am replica
1936 Diamond T 212BD
1990 Grizzly pick-up

blykins

  • Hero Member
  • *****
  • Posts: 5132
    • View Profile
    • Lykins Motorsports
Re: SBF valvetrain grief - Help needed please!
« Reply #5 on: August 20, 2025, 04:53:46 AM »
I didn't even see the pics first time around. 

Cory is right, #7 and #8 poly lock set screws are not in the same location as all the others.  That should be an indicator of something...

The rocker arms have the typical Chinese font on them.  It could be that they're just cheap rockers and can't handle the setup. 
Brent Lykins
Lykins Motorsports
Custom FE Street, Drag Race, Road Race, and Pulling Truck Engines
Custom Roller & Flat Tappet Camshafts
www.lykinsmotorsports.com
brent@lykinsmotorsports.com
www.customfordcams.com
502-759-1431
Instagram:  brentlykinsmotorsports
YouTube:  Lykins Motorsports

frnkeore

  • Hero Member
  • *****
  • Posts: 1243
    • View Profile
Re: SBF valvetrain grief - Help needed please!
« Reply #6 on: August 20, 2025, 11:03:47 AM »
I don't know but, usually when a guild seizes, it stays seized, because it galls.

I also think that the lifter has bottomed out, to brake the ball off the PR. I'd take a close look at the coil bind and retainer clearance.

It would also be a good idea, to use a endoscope in that cyl, to see if the valve hit the piston.
Frank

'60 Ford Starliner
Austin Healey Replica with 427 & 8.5 Cert

427Fastback

  • Hero Member
  • *****
  • Posts: 616
    • View Profile
Re: SBF valvetrain grief - Help needed please!
« Reply #7 on: August 20, 2025, 11:37:27 AM »
I don't know but, usually when a guild seizes, it stays seized, because it galls.

I also think that the lifter has bottomed out, to brake the ball off the PR. I'd take a close look at the coil bind and retainer clearance.

It would also be a good idea, to use a endoscope in that cyl, to see if the valve hit the piston.


Agreed........
1968 Mustang Fastback...427 MR 5spd (owned since 1977)
1967 Mustang coupe...Trans Am replica
1936 Diamond T 212BD
1990 Grizzly pick-up

Kevin66

  • Jr. Member
  • **
  • Posts: 45
    • View Profile
Re: SBF valvetrain grief - Help needed please!
« Reply #8 on: August 20, 2025, 06:36:30 PM »
First I would ask how you are adjusting them, EOIC method?  Only checking to make sure you don't have the exhaust loose and spitting pushrods

Second, what is your installed height for the springs?  They list as 1.100 bind, that means if you want .080 away, 1.180 + lift .587, you need 1.78 installed height.  However, I check every spring for coil bind, and sometimes you can be slightly higher.  I looked at the FT springs and they are at 1.800 but the HR version is at 1.7500, depending how you shimmed your springs, also spec'd at 1.750 from Trick Flow, you could be right at the edge

Third, look at the cam card and make sure your lobe lift multiplied by 1.6 is what you are figuring for valve lift.  If the cam was planned for less rocker you could have more lift than planned.

Last, did you check clearance with clay and a solid roller at assembly?

It does seem that the exhaust is the issue, and it is the higher lift lobe, so I would start there


Thanks for your thoughts, I do appreciate the input. I'll try to answer your questions and concerns.
The method I use to adjust valves is to have the opposite number in the firing order to the one you're working on at full valve lift, then adjust the other one. So #1 at maximum lift, adjust #6; #3 at max lift, adjust #5; #7 at max lift, adjust #4, etc.

When degreeing the cam, it was found to yield a little less lift than the cam card indicated - .568" on the intake, and .580" on the exhaust, versus Lunati's .571"/.587" spec.

During engine mock-up, clay was used on the valve reliefs of the #5 piston. The FT springs were removed on that cylinder and replaced with lightweight checking springs. I did not have a SBF solid roller lifter, so a HR lifter was used, after pressurizing with oil. These valves were adjusted for zero lash + 1/2 turn, then the engine was rotated by hand through four complete revolutions. With no head gasket in place, the valve-to-piston clearance measured .078" on the intake, .083" on the exhaust. The Ford Racing head gaskets are .040" thick, so the actual clearance would then be .118" Int, .123" Exh. So valve to piston clearance should not have been an issue, as also evidenced by the 160 +/- compression specs.

When the Flo Tek FT springs/retainers/keepers were removed, they were simply replaced with the Trick Flow parts. I did not have a height mic here so no measurement was taken. All of the HR lifters were pre-lubed prior to the initial valve adjustment, and no binding was felt as the engine was rotated by hand through numerous revolutions. So it was assumed...foolishly I see now...that we had the necessary clearance.

Amazon is supposed to be bringing me a height mic tomorrow, and we will begin a thorough check of what clearance is actually there. I concur that the exhausts may well be the culprit, but I doubt that the intakes are much better.
"In theory, theory and reality are the same. In reality, they are not!"

Kevin66

  • Jr. Member
  • **
  • Posts: 45
    • View Profile
Re: SBF valvetrain grief - Help needed please!
« Reply #9 on: August 20, 2025, 07:48:26 PM »
If you drove it 18 miles without an issue, and then after sitting for a bit and starting it up again it developed a problem immediately, I would look at valve guide clearances.  Especially if only exhaust rockers or pushrods.  JMO, but look at that, also.  What is that white substance in the intake ports?  Thread sealer for the studs?  Make sure you remove that before installing the intake next time.   Joe-JDC

Thanks Joe. I had considered that, but then dismissed it, feeling that it wasn't likely a guide could grab a valve tight enough to break a rocker arm in pieces? But I do note your suggestion about looking at the exhaust side first.

As for the thread sealer, yes that's what it is. But this photo was from during engine assembly and setup, and it was removed prior to intake installation and startup.

Incidentally, that is one NICE intake manifold you did up! Obviously with the problems we've had, and the sub-3,200 RPM speeds so far, we haven't been able to give it a good run, but are certainly looking forward to doing so.
"In theory, theory and reality are the same. In reality, they are not!"

Kevin66

  • Jr. Member
  • **
  • Posts: 45
    • View Profile
Re: SBF valvetrain grief - Help needed please!
« Reply #10 on: August 20, 2025, 07:57:52 PM »
I didn't even see the pics first time around. 

Cory is right, #7 and #8 poly lock set screws are not in the same location as all the others.  That should be an indicator of something...

The rocker arms have the typical Chinese font on them.  It could be that they're just cheap rockers and can't handle the setup.

Brent thanks for chiming in here. As you and Cory noted, there are differences between the #7 & #8 polylock set screw and the others. During the Re & Re of the valve springs from the original FT ones to the lightweight checking ones, a rocker stud bent using one of those over-centering, screw-on spring compressors. The replacements I received were not the same as the original Flo Tek ones. I think they were 1.895" effective length Vs the 1.75" of the rest. It seemed like the relative position of the Allen-head lock screw was the only thing affected, so they were used.

Oh, I meant to ask you...in your first post you mentioned "pushrod hitting the rocker" as one possibility to look out for. What did you mean by that? I'm having trouble visualizing it.
"In theory, theory and reality are the same. In reality, they are not!"

My427stang

  • Hero Member
  • *****
  • Posts: 4202
    • View Profile
Re: SBF valvetrain grief - Help needed please!
« Reply #11 on: August 20, 2025, 09:42:58 PM »
My take in your quote after each section below, I hope it doesn't sound too blunt, but every single one of the things I recommended I do with every single engine build and hydraulic rollers are by far the most common for me in both SBFs and FEs.

Thanks for your thoughts, I do appreciate the input. I'll try to answer your questions and concerns.
The method I use to adjust valves is to have the opposite number in the firing order to the one you're working on at full valve lift, then adjust the other one. So #1 at maximum lift, adjust #6; #3 at max lift, adjust #5; #7 at max lift, adjust #4, etc.

That seems like it might work, but that hurts my head :) nobody needs to try to educate me why it might work, EOIC is easy and industry standard and not affected by cam design.  As the exhaust valve starts to open, adjust the intake, as the intake valve starts to close, adjust the exhaust.  It's easy and fast and works for every engine, and make sure you turn it the right direction

When degreeing the cam, it was found to yield a little less lift than the cam card indicated - .568" on the intake, and .580" on the exhaust, versus Lunati's .571"/.587" spec.

That makes sense, you lose a little than the strict ratio provides, especially if you didn't optimize the pivot height, but how about ICL, is it where you expected (not too advanced or retarded)

During engine mock-up, clay was used on the valve reliefs of the #5 piston. The FT springs were removed on that cylinder and replaced with lightweight checking springs. I did not have a SBF solid roller lifter, so a HR lifter was used, after pressurizing with oil. These valves were adjusted for zero lash + 1/2 turn, then the engine was rotated by hand through four complete revolutions. With no head gasket in place, the valve-to-piston clearance measured .078" on the intake, .083" on the exhaust. The Ford Racing head gaskets are .040" thick, so the actual clearance would then be .118" Int, .123" Exh. So valve to piston clearance should not have been an issue, as also evidenced by the 160 +/- compression specs.

Goofing around a bit, but again, hurting my head.  You WILL have more with real springs, you SHOULD have more with the head gasket, but it may not be linear, and I am not sure you can truly tell you had seen the real lift with that method with the hyd roller.  A single solid roller is cheap, I do not believe that your lifter setup could be guaranteed to be not compressing, nor can it be sure it didn't compress a little when it hit the clay.  I will say I made a little inverted top hat that I use with hyd rollers and a pushrod length checker, it takes the plunger out of the picture, but I usually use a solid roller unless I can't get a pushrod length to work for checking, then I use the top hat

When the Flo Tek FT springs/retainers/keepers were removed, they were simply replaced with the Trick Flow parts. I did not have a height mic here so no measurement was taken. All of the HR lifters were pre-lubed prior to the initial valve adjustment, and no binding was felt as the engine was rotated by hand through numerous revolutions. So it was assumed...foolishly I see now...that we had the necessary clearance.

I do not believe it is a rocker or pushrod problem, ball/ball pushrods usually don't contact, a rocker trunion that style usually can rotate 360 degrees (if unbolted), and although Brent is right about the slot in the aluminum, it would have to be seriously wrong pushrod lengths and pivot point to have them smack that style, still worth checking though!  Additionally, the rocker could be hitting the spring if too large of an OD, to check that, look at the bottom of the rockers toward the springs, they'll be chewed up.  However, a spring height not measured is almost always wrong in both pressure and height from what you want. In fact, after setting up too many heads, I haven't found springs that match each other in pressure or coil bind, or installed heights that match each other without shimming.  High end heads are closer, but even those vary It really takes some thinking sometimes.  It is very likely your spring and retainer combo doesn't match your heads and cam.

Amazon is supposed to be bringing me a height mic tomorrow, and we will begin a thorough check of what clearance is actually there. I concur that the exhausts may well be the culprit, but I doubt that the intakes are much better.

Given what you wrote here, I believe you had many things you need to look at even if you find installed height wrong tomorrow. 

1 - Verify spring height, and it would be even better if you had someone check pressures and coil bind
2 - Once you verify or fix that, check clearance again with a solid lifter using EOIC on that one cylinder (there are other ways to cheat if you don't have one like my top hat, but given where you are, a single would be cheap to do, and at the same time look for the rocker hitting anywhere
3 - Reassemble and set preload by the EOIC method... EOIC is so much less thinking and not cam profile dependent. Your zero+1/2 is good, but be very careful where you determine zero is, and if any of the adjusters look different, check again, we all do that as a BS test.

In the end though, at any one step, if you do find something wrong, don't stop there, do the other things too.  As I said it's not "some engines" guys like me and the other guys do this way, it's absolutely all that we go through those steps.

Thanks for taking the time to spell it all out, the answer is there, just need to check everything (and on EDIT...get the right rocker studs for the mismatching ones)
« Last Edit: August 20, 2025, 10:06:13 PM by My427stang »
---------------------------------
Ross
Bullock's Power Service, LLC
- 70 Fastback Mustang, 489 cid FE, Victor, SEFI, Erson SFT cam, TKO-600 5 speed, 4.11 9 inch.
- 71 F100 shortbed 4x4, 461 cid FE, headers, Victor Pro-flo EFI, Comp Custom HFT cam, 3.50 9 inch

blykins

  • Hero Member
  • *****
  • Posts: 5132
    • View Profile
    • Lykins Motorsports
Re: SBF valvetrain grief - Help needed please!
« Reply #12 on: August 21, 2025, 04:39:04 AM »
I didn't even see the pics first time around. 

Cory is right, #7 and #8 poly lock set screws are not in the same location as all the others.  That should be an indicator of something...

The rocker arms have the typical Chinese font on them.  It could be that they're just cheap rockers and can't handle the setup.

Brent thanks for chiming in here. As you and Cory noted, there are differences between the #7 & #8 polylock set screw and the others. During the Re & Re of the valve springs from the original FT ones to the lightweight checking ones, a rocker stud bent using one of those over-centering, screw-on spring compressors. The replacements I received were not the same as the original Flo Tek ones. I think they were 1.895" effective length Vs the 1.75" of the rest. It seemed like the relative position of the Allen-head lock screw was the only thing affected, so they were used.

Oh, I meant to ask you...in your first post you mentioned "pushrod hitting the rocker" as one possibility to look out for. What did you mean by that? I'm having trouble visualizing it.

You're getting less lift at the valve because of valvetrain deflection.  My habit is to always measure lobe lift, so that you know the cam is ground correctly.  I do it as part of the degreeing process.  Then when you know that, you do whatever you can to eliminate any valve lift loss.

On some combinations, at full lift, the pushrod will hit the back of the rocker arm.  Probably won't happen on a 1.6 rocker, but you can run into it on a 1.7. 

On your valve setting procedure, use the EVO/IVC method. 
Brent Lykins
Lykins Motorsports
Custom FE Street, Drag Race, Road Race, and Pulling Truck Engines
Custom Roller & Flat Tappet Camshafts
www.lykinsmotorsports.com
brent@lykinsmotorsports.com
www.customfordcams.com
502-759-1431
Instagram:  brentlykinsmotorsports
YouTube:  Lykins Motorsports

MeanGene

  • Hero Member
  • *****
  • Posts: 549
    • View Profile
Re: SBF valvetrain grief - Help needed please!
« Reply #13 on: August 21, 2025, 08:22:59 AM »
EOIC is brutally simple and always works, over-thinking it can get one in trouble. If I haven't done one in a while, it's pretty easy to run the cycle in your head and refresh yourself.
Swapping springs without checking installed height and pressure is dangerous- if one doesn't have the tools/ equipment to do it, you can find someone who does

Kevin66

  • Jr. Member
  • **
  • Posts: 45
    • View Profile
Re: SBF valvetrain grief - Help needed please!
« Reply #14 on: August 22, 2025, 09:00:47 PM »
I didn't even see the pics first time around. 

Cory is right, #7 and #8 poly lock set screws are not in the same location as all the others.  That should be an indicator of something...

The rocker arms have the typical Chinese font on them.  It could be that they're just cheap rockers and can't handle the setup.

Brent thanks for chiming in here. As you and Cory noted, there are differences between the #7 & #8 polylock set screw and the others. During the Re & Re of the valve springs from the original FT ones to the lightweight checking ones, a rocker stud bent using one of those over-centering, screw-on spring compressors. The replacements I received were not the same as the original Flo Tek ones. I think they were 1.895" effective length Vs the 1.75" of the rest. It seemed like the relative position of the Allen-head lock screw was the only thing affected, so they were used.

Oh, I meant to ask you...in your first post you mentioned "pushrod hitting the rocker" as one possibility to look out for. What did you mean by that? I'm having trouble visualizing it.

You're getting less lift at the valve because of valvetrain deflection.  My habit is to always measure lobe lift, so that you know the cam is ground correctly.  I do it as part of the degreeing process.  Then when you know that, you do whatever you can to eliminate any valve lift loss.

On some combinations, at full lift, the pushrod will hit the back of the rocker arm.  Probably won't happen on a 1.6 rocker, but you can run into it on a 1.7. 

On your valve setting procedure, use the EVO/IVC method.

Thanks again everyone, for all the information and guidance. I have a height mic now and will begin checking all the installation clearances this evening.

As for the EO/IC valve adjustment procedure, I have a question for those of you who use it. I've seen it written, and heard a couple people mention, that they just rotate the engine a little past the actual opening and closing points (whichever is relevant to the valve you're working on), then do the adjustment. However I've also seen it mentioned (I'm including pics of two) where they say to go way past the maximum lift point with the intake closing and then make the adjustment on the exhaust valve. What do you all use/recommend?
"In theory, theory and reality are the same. In reality, they are not!"