[DeTomaso] Valve cover sound, strangest question of the day?->new developments

Sun May 11 10:42:38 EDT 2014

While on the subject, is it possible to use the bolt down FMS roller 
rockers on aluminum heads or is guide plates and poly locks needed?

I really like the solidly bolted down FMS roller rockers I have, which 
is shimmed to the appropriate pre-load, but I have started looking at 
new heads, given the good results with the TrickFlow heads Dan Jones 
tested in the Dyno project.

Thomas

Mikael skrev 2014-05-11 14:07:
> I do believe the mail below didn't get to you guys, picture too big.
> Resending, because now I've fixed the issue and come to a conclusion after
> several detours.
>
> -My valve train was binding after replacing lock nuts, even though rockers
> are Comp Cams and locks are also Comp Cams with smallest possible OD
> (0.600"). Go figure. Had to buy Crane Cams lock nuts, they're 0.550", no
> binding
> -Metallic sound had nothing to do with material of valve covers, it was the
> binding
> -For reasons I still don't understand, the binding valve train produced a
> lot better idle, maybe less lift and thereby less overlap. Doesn't matter,
> can't drive around with binding stuff
> -I've always adjusted rockers between 1/2 and 3/8 turn, now I use 1/8 to
> 1/4, modern hydraulic lifters don't have that much play in them as in the
> old days
>
> Idles fine now, just waiting for a no rain day...
>
> Mvh/Regards
> Mikael
> +45 31770747
> mikael_hass at mail.tele.dk
>
>
> -----Oprindelig meddelelse-----
> Fra: Mikael [mailto:mikael_hass at mail.tele.dk]
> Sendt: 29. april 2014 22:25
> Til: 'Mike Thomas'; 'detomaso at poca.com'
> Emne: SV: [DeTomaso] Valve cover sound, strangest question of the day?->new
> developments
>
> Prepare for a long mail... Again ending with probably the strangest question
> of the day. Cleveland specialists, please read on.
>
> So, see the previous mail below.
> --
> So based on the mail below, I was happy, well, not really. The grinding
> engine sound was definitely reduced, but not gone. If I remembered
> correctly. Did I? Couldn't really sleep, next day out and diagnose some
> more. I noticed that some pushrods were very loose, but since I hadn't a
> tick tick, I thought it must be lifters collapsing when engine is not
> turning. But when I turned the lock nut slightly, the rocker banged down,
> and now the pushrod was not loose any more. My valve train was binding! How
> could it? The only thing I had changed during winter were the lock nuts.
> A-ha! So I took one off, and yes it was deeply scratched, so was the rocker.
> But why, I got the ones Comp Cam recommends? Here's why. The original locks
> were .600 OD except the lower 2mm which were .550. The new I got (correct
> according to Comp Cams catalog) were .600 all the way up and down. And
> that's too wide for my rockers. Couldn't understand, I have pretty standard
> Cleveland alu heads and the 1.73 red Comp Cams rockers, I think a lot of us
> have, right? I called Comp Cams, and while I could hear that they in no way
> wanted to admit to a problem, they said that the lock nut with only .550 at
> the bottom was discontinued, and that they didn't have anything smaller than
> .600. So no help there. I told him that Crane has them in .550 all the way,
> he said, so use them. So I ordered a set, and put them on tonight. No more
> binding. Isn't that wild? These red rockers are used by so many people, and
> they produce locks that don't fit? Am I missing something?
>
> See attached picture. Grind marks visible on rocker both top and bottom.
> Lock nuts from below:
> -Original with .550 bottom 2mm
> -New for this winter .600 all the way, grind marks at bottom -Just bought,
> .550 all the way
>
> ---
> So now all should be fine, no binding, no unpleasant engine noises. But oh
> no, now it gets complicated. First a little history. Ever since I got this
> Pantera with its 600HP 408 MME engine, I've had a challenging idle, with max
> 10-15 vacuum if all was adjusted perfectly. I thought, wild cam, that's just
> the way it is, right? But this spring, I've had a much better idle, above
> 20, idling like a daily driver. I never understood why, the only thing I
> could think of was that I had had the intake off and on, maybe I had fixed a
> vacuum leak, but I've had that intake on and off several times, and this is
> the first time I've had this perfect idle. Couldn't explain it, and still
> can't. Here comes the problem. Since my valve train doesn't bind anymore,
> the idle is back to around only 10. How is that possible? How can one set of
> locks produce a perfect idle (and bind) and another set produce a lousy
> idle?
>
> I have a theory. Since the locks I put on this winter were binding, when
> adjusting the rocker lock height, it must have pushed the rocker down "too
> early", and when the engine then got started the valve spring force etc
> quickly ground off some of the rockers and locks and allowed the rocker to
> move up slightly, just like a very loose setting. In theory it could work.
> To prove my theory and to get back to a 20+ idle, I therefore tried
> loosening the rocker lock nuts in 1/4 turn increments. Idle got a bit
> better, but never near the 20+, and then when I continued, they started to
> tick, so too loose I guess.
> ---
> Q1: Anybody else had binding problems with standard Comp Cams valve train
> parts?
>
> Q2: Any ideas why I had perfect idle with binding lock nuts? And how I get
> back to perfect 20+ idle?
>
> Q3: How should I adjust these rocker lock nuts? Here's how I've always done
> it: TDC, cyl 1, tighten until pushrod starts to bind, +1/2 turn, tighten
> counter hex bolt, turn lock nut and hex bolt at the same time to tighten
> approx. 1/16, then turn engine 1/4, next cylinder, do it 8 times.
> That has worked for me for years, but, I must admit, produced the less than
> perfect idle on my Pantera. Is there a better way? Tonight I also tried the
> Chevy SB way, covers off, idle, turn loose until tick tick, tighten 1/2
> turn. Didn't give me a better idle.
>
> I'm confused. And I want my perfect idle back! Or I'm buying a Porsche!
>
>
>
>
> Mikael
>
> -----Oprindelig meddelelse-----
> Fra: Mikael [mailto:mikael_hass at mail.tele.dk]
> Sendt: 13. april 2014 15:10
> Til: 'Mike Thomas'; 'detomaso at poca.com'
> Emne: SV: [DeTomaso] Valve cover sound, strangest question of the day?
>
> Wise words. Took the fabricated covers off, and yes, there had been contact.
> Found out that the local fabricator that I got to install a plate to avoid
> oil at PCV etc., I asked him to raise max 15 mm and he raised 17 mm. So I
> dented and grinded (ground?) that off so there was no contact. It sounded
> like a Pantera again. But I had also tried my previous very high "Ford
> Racing" covers, and they sounded best, least valve train noise, most exhaust
> noise.
>
> Mvh/Regards
> Mikael
>
>
> -----Oprindelig meddelelse-----
> Fra: Mike Thomas [mailto:mbefthomas at comcast.net]
> Sendt: 12. april 2014 18:16
> Til: 'Mikael'; detomaso at poca.com
> Emne: RE: [DeTomaso] Valve cover sound, strangest question of the day?
>
> If you are talking about the cast aluminum valve covers with DeTomaso on the
> top, and you are running a set of aluminum roller rockers, you may be
> experiencing interference between the rockers and the baffles in the valve
> cover.  When I had my motor built in '07, I had my builder install a set of
> aluminum roller rockers (don't recall the brand without digging out my build
> sheet) which were a rather blocky casting.  Mine are blue (not sure if that
> means anything, FoMoCo?), but have seen the same from other manufacturers.
> There was quite a loud ticking that I thought to be much more serious than
> the truth.  What was happening was that the corners of the rockers were
> contacting the angled portion of the oil fill and vent baffles in both valve
> covers, and I had to remove the covers, remove the baffles, relieve that
> area of the baffle with a slight peening, and reinstall them (never just
> take them out and toss them!!).  You can check easily by removing the valve
> covers and looking at the baffle, or the corner of the rocker, and you'll
> see a wear spot.
>
> The strange part about this one is that you don't hear the noise at first,
> likely because the rocker doesn't leave contact with the baffle until there
> is a little wear in the softer aluminum material on the rocker, and the
> baffle is scratched a bit, then the noise is much like a stuck lifter or
> bent push rod as it's coming from the top of the motor.  Also, trying to
> peen or relieve the baffle while it is still in the valve cover is very
> difficult as it is very easy to bend the baffle so it no longer stays seated
> in the cast lip in the cover meant to keep it in place.  You could possibly
> do this with a Dremmel tool with a small grinding head.  I'm not sure if
> polishing off the corner of the rocker is a good idea for balance or
> strength issues with the rocker.
>
> One local member recently had a bunch of us up to pull his motor.  Said
> there was this horrendous whacking noise coming from his brand new build.
> The builder, located in California, told him the only way he'd check it out
> was if the owner pulled the motor and shipped it back to him.  So, we have
> the motor out an on the pallet, just before we were going to strap it down
> and wrap it, and I mentioned to the guy "let's pull a valve cover and take a
> look".  Sure enough, that was all it was.  He pulled the manifold later to
> be sure there were no valve lifter issues or other obvious problems, but all
> else seems to be in good order.  He was completely embarrassed to have had
> pull his motor for such a simple fix.
>
> Good luck.
> Mike Thomas
> VP, POCA
> VP, Panteras Northwest
> Yellow '74 #6328
>
>
>
> -----Original Message-----
> From: DeTomaso [mailto:detomaso-bounces at poca.com] On Behalf Of Mikael
> Sent: Saturday, April 12, 2014 8:49 AM
> To: detomaso at poca.com
> Subject: [DeTomaso] Valve cover sound, strangest question of the day?
>
> This may seem like a strange question, but has anyone experienced a change
> in the mechanical sound of an engine by switching valve covers? I replaced
> the Ford Racing chrome covers this winter with fabricated alu valve covers.
> Man, they look good. But at idle, now I hear more valve train noise than
> exhaust noise. Can this be? I can of course have a valve train issue, but I
> don't think so.
>
> Mvh/Regards
> Mikael
>
>
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-- 
Real life:   Thomas Törnblom             Email:    thomas at hax.se
Snail mail:  Banvallsvägen 14            Phone:    +46 18 32 31 18
              S - 754 40 Uppsala, Sweden  Cellular: +46 76 209 8320