Tony D

Android... argh... Now I got to buy an Android Tablet or something so I have this back. I worked with 'reed boxes' for years and this sounds as accurate as those were. You're dead nuts correct: a few calculations and you can know EXACTLY where to look! REALLY want to say thanks for this little tidbit. Now, to see if I can justify it for work so I don't have to pay! How cheap is THAT!?!?!?...

A halfshaft will cause vibration. What was the APP mentioned for the smartphone that shows the frequencies? If it was named, I missed it, that would tell you right away where it's coming from. "In the Old Days", Ford Field Reps going out on an NVH Complaint had a reed box--you went for a drive, and looked at these little reeds vibrating. When they excited, you read the frequency... Then crossed it to a list of known frequencies at various speeds. Sounds lo-tech as hell, but MAN it was like a magic divining rod. I was out on one where it said to look at the alternator bearings... Guess what the source of the noise was? SAS: Bad alternator! Mercury and Lincoln owners were a PITA!

Couldn't log on last evening via iphone to say "Your measurements are done static, not under load." The thing may be perfect, but under the loads imposed at speed an angularity is introduced that causes this phenomenon...

Data Entry Field for Edits SUCKS NOW!

And I don't know what "Precision Machine Shop" means, as any guy with a Bridgeport Mill and Starrett Last Word indicator can do the setup on this repair after half a bottle of Jack Daniels and a weekend in Vegas... There are more than enough NC Shops in Illinois (well, maybe not Rantoul...) to do this work. A PHOTO should be worth a thousand words on this one... As I can't see how all this work was done and 'Poor Helicoils' went undetected until assembly! <div><br></div><div>Were I doing this in the back shed:</div><div><br></div><div>Measure pin bore.</div><div>Set up on pin bore centerline.</div><div>Drill / Ream for Keen Sert & Install.</div><div>Top Cut appropriately for bottom of Pin Bore</div><div>Bore Oversize for Locally-Fabricated Step-Pin</div><div>Install Step Pin</div><div>Reassemble...</div><div><br></div><div>Maybe more than an hour, forgot to take step-pin into consideration...but then again, making a SOLID over sized threaded-in Step-Pin to locate the tower is more involved (permanent, too, as the external threads on the lower portion of the step pin and inner threads for the bolt will NEVER come out or strip! But I digress...</div><div><br></div><div>This is all basic machine shop stuff. There is no 'specialty shop' required. Just a 'competent' one!<img src="http://forums.hybridz.org/public/style_emoticons/default/dry.gif" alt="<_<" class="bbc_emoticon"></div>

I refuse to use Twitterisms like "@Kash" but it should be inferred my reply (since I replied above earlier) is in response to the newest response...which doesn't state that. Having work done on a linered head... OK, suit yourself... But proper machine shop would check / tap these holes and pay particular attention to any previously installed Helicoils. Stripping out a Helicoil is EXTREMELY difficult unless you MASSIVELY overtorque the fastener. Has nobody measured the tapped depth of the hole and seen if a 'deep Helicoil' can be installed in the threads deeper down the hole. On an M8 Helicoil, they are ONLY 8mm Deep. That's all you need for full grip strength. On bare aluminum threads maybe more than that, but assuming the standard Helicoil was installed, then reefed out, a slightly longer bolt, along with a Helicoil at the bottom of the existing hole would do the job. This is basic machine shop stuff. That the shop didn't know this is disappointing. Pulling a locating dowel and re-reaming halfway through a Keen Sert is not a big deal, and I can't see why the OP is so resistant to doing this. We're talking a $50 repair to a head which I have to assume has $2,400 in head work by the way it's played up. Seriously, if you got $350 into it for a valve job and a 'port cleanup' shelve it, get another, and save the head for when spending $50 for a repair on a Linered P79 makes economic sense. You got $2400 into the head, this repair is a no brainer. Does he have $2400 into the head? If not.....

You need to state which year, they aren't all the same "75+"! Some have welded pieces for bumper fillers, others have the same piece attached with M6 Bolts....

Leave it like that, and see if anybody notices...

Jeebus who's been working on these heads?!?!?!?! Put it on a shelf and get another from a JY while you still can. Later, the head can be machine repaired when there is no alternative.

Check that the driveline is STRAIGHT between the tailshaft flange and the differential flange. If there isn't a STRAIGHT and PARALLEL to each other, you will get this type of vibration. Your hint was loosening the tailshaft mount cable. That altered the angle of the U-Joints in the driveline between tailshaft and differential. My case was the transmission was 'walking' sideways, causing the vibration. Yours may not be deflecting sideways, but you may have (view the driveline from the side to visualize this) a tailshaft that when put up against a square on a chassis plate 89 degrees on it, and the RT mount from what I've been told pushes the nose of the differential down a few degrees (so using the same scale it would be at 94 degrees)... If those aren't parallel (in other words, both flanges at 89 degrees and concentric centerline to centerline, you will have this type of vibration. ALIGNMENT more than BLANCE can make for terrible headaches here!

I have no clue WTF is going on with the data entry field, but it's FUBAR and trying to 'fix' the post through editing just makes it worse!

<div><br></div><div>That's a function of the cam more than the induction. There are thousands of cars out there in OEM configuration (including the original Z-Car in 165HP L24 Configuration) that used vacuum advance on their Mikunis... In fact there is a little green canister with a Nissan P/N (or Toyota if you prefer) that was used on some OEM Mikuni Applications to eliminate the issue of excessive or pulsating idle vacuum to the distributor. Just take it off the Mikuni's first barrel port, and go from there, no log required! Returned 28mpg at 65mph steady highway driving on a 2.4L with stock cam, 4.11 gearing, and an autobox. Spinning the dyno to around 163 (back in 1989 when Aftermarket EFI was still a rich man's game.)</div><div><br></div><div>Webers? Sorry, no advance port, but Solexes have one, and for good reason, at light cruise vacuum advance saves gas, and there is no reason not to use it!</div><div><br></div><div>But to answer 'which one' can only be answered: "Recurved"<br><br><br> </div>

"Putting the Stand on the Engine is easier than putting the Engine on the Stand!"

(Yawn) Lets angulate the penis and see how high on the fencepost we can go gentlemen... Blah Blah Blah... Take advice someone once gave me: "It's not all that difficult, you can figure it out if you're smart enough!"

5th spins the everything from the tailshaft back faster than the flywheel input speed. That points to driveline. I'd check mounts and make sure everything is straight like it should be.

It won't prevent it from working, but the Turbo ECU's are TERRIBLY sensitivity to low voltage and will FRY the injector drivers from over amperage if your charging system isn't up to snuff. You don't "HAVE" to remove your external regulator. If you simply connect the stock ZXT Alternator you will have a helluva time flashing field, but if you drive the car daily or even weekly there is enough residual magnetism in the rotor core to excite the field by revving the engine to around 3K rpms. Once you do it first thing in the morning, it's good for the rest of the day, quick blip of the throttle and the alternator is producing. I drove my 260 for almost 18 months like this until I had the time and found a spare regulator that was bad to construct the diode plug. I had a good regulator in there, and didn't want to cut the plug off of it to make the jumper and diode---it will tend to 'not shut off' because of the lack of a diode, but I'm tolerant...I would dump the clutch to kill the engine and then flip my battery disconnect switch while it was parked. So yeah, do the modification. I wouldn't use the 260 alternator if I had a good internally regulated one from the L28ET already hung on the block! It's way better.

I do the same thing as the two above! Also, I have used a strap and come-along over a standard 2X4 Rafter Truss to lift the engine complete. I have a Truss-Roof Tuff-Shed that I use for Engine Assembly, and they arrive in pieces, and either go out on a stand to the pickup bed, or I put the strap over the truss and hang it till I drop it onto the Harbor Freight Rolling Cart (600# Capacity)

"Might add that that RWD ToyoSubi coupe thing is selling like hot cakes in AU, to me it's a reincarnation of the S30 in concept, pricing.... Problem is that the AU market is nothing compared with the US so we can get a bit frustrated with what RWD coupes are available to us and at what price." Let me cry crocodile tears for you sir.... A market with 22million people gets Holden Sports Utes with massive HP A Ford Falcon Ute with a big inline six (also in their coupe/sedan), a TURBO INLINE SIX, and a V8.... (and a company history of favouring the inline six over the V8, Mad Max's Garage Partner nothwithstanding!) The USA gets nothing. GM-H was the ONLY profitable division in GM when they went bankrupt... HUGE investment in motorsports and performance vehicle marketing specialty vehicle divisions that actually produce roadgoing cars... And all sorts of Nissan Stuff not available here. CALIFORNIA has 54 million people, WTF? WHY are we tethered to the Ossified Brains in Dearborn, The Ren Cen, and Aburn Hills? Why can't WE get a standalone division just like GM-H or Ford AU? WHY WHY WHY WHY WHY WHY WHY!!!!!!!!???????

Plenty of Motec out there on big HP setups. Cheap Shot. Plenty of DCRE's out there at 1100 N/A HP running a carburettor, what's the point?

Ditto the loctite comment, it releases it's hold at 400F... As for not using lockwire on nuts...uh... "why not"? There are plenty of military assemblies with safety-wired nuts, though Grade-C locknuts make for quicker assembly. If your nuts are coming loose, you are not properly torquing them to proper tension beforehand. Got to the "Bolt Science" website, and run their example video of the "Junkers Test" to see why tightening a bolt properly is the ONLY mechanical method to prevent loosening, and why split lockwashers and most other lockwashers are a waste of time when it comes to high vibration assemblies.

At the bottom of those now defunct Red Horse 12.5% Beers... Duals... Though I did have a 5M that ran triple 44IDF's!

Flywheel and pressure plate need to be balanced and match-marked as a set... I ditto that advice. I would look at the clutch cover closely! Chances are it is your culprit.

"Valve Recession"--ideally your inspection/adjustment intervals would be at a point before there is zero clearance (from an engineering standpoint)... From a practical standpoint you want recession to be uniform on all cylinders and SLOOOOW! The valves bang into the seat, and on a fresh engine can be quite profound. After the first 10K miles this should stop the radical changes and settle in to a normal recession range which means 0.002-0.003" per 25-30,000 miles (you convert to metric!) If your valves become too tight, you get "hot valves" from not enough contact dwell time on the seat to transfer heat out of the valve, causing burning problems. if it is uneven and continues unevenly after 10K miles...something is wrong. Maybe a valve stem is pulling, or a seat was not properly installed and is hammering out. It bears investigation. Keep checking regularly every 500KM or so, until you see them even out and settle in to the 'long term' recession pattern. Remember there was a 50,000 or so regular adjustment interval, that was for stock stock stock. Heavier springs and higher rpms may call for readjustment at 25 or 30,000 km instead of the original 50K

Interesting 4bbl TB...

Probably... but being in The Philippines, and those receipts being 'somewhere' at home I believe the quickest course of action would be to call and ask MSA...