Timing Marker off 90 Deg???

[BillZ260]

Back info:

I have a small block that has maybe 1000 miles on it since the rebuild. Everything is new, I had been chasing an oil leak for quite a while. I though it was the pan but ended up being the TChain Cover. Since I have replaced that it hasn't really run right. Around the same time I was working on my hood latch that required the removal of the dizzy as well.

 

What's going on now:

Car runs decent, has good vaccum, around 18 @ idle and it's never iradic. After about 20 min or so on the road, the temp starts to climb and when I park it, the hood is HOT.

 

What I've tried:

I figure the timing is off so today I re-established my TDC with a dial indicator through the Spark plug hole, and get it set, nothing seems off at this point. So I unhook the vac advance, set my timing light to 0 and start her up. It's pointing almost DEAD on the 90 Deg mark at idle. It didn't do this when I first built the motor but the car has never really been dialed in very well either for lots of various reasons.

 

SO, is my dizzy off one tooth or what? The car idles fine, but I'm afraid to finish the tune with the timing off this far.

 

Another board suggests that my ballancer slipped but, it is new and it seems that the mark is EXACTLY 90 Deg off.

 

What do you guy's think?

[grumpyvette]

you can forget the dissy being one tooth off, thats B.S., you can get a distrib to run with the rotor in almost any location, (not correct, but it will run fine) simply by moving the plug wire locations

 

the most comon problem that causes that timing mark to move is the elastomer ring in the damper slipping OR use of the wrong timing tab location.

dampers with the stock design ELASTOMER ring only work effectively at one set rpm range, usually in the 2400rpm-3000rpm band where the stock engine and gearings designed to cruize at in most cars. oil , heat,time and fuel can degrade the damper elastomer and make it fail.

the IDEA is that the inner ring accellerates with the power strokes, the flex the crank but the outer ring being connected with a rubber ring and glue tends to resist and absorb the shock loads,lowering the shock loads on the crank, the absorbtion frequency naturally depends on the outer rings weigh, and dia. and the thickness and flexiability.

some of the aftermarket dampers are much better designs and opperate at all rpm ranges.

 

THERES TWO COMMON REPLACEMENTS

Silicone performance from Fluidampr.

Using only 3 parts--a laser-welded sealed housing, an internal inertia ring, and a highly viscous silicon fluid between the two--these SFI-approved Fluidamprs can control all crankshaft vibration, not just a limited frequency range. As a result, you get reduced wear on the main bearings and timing gear, more stable valvetrain operation, and less chance of crank failure.

 

 

 

the aftermarket FLUID DAMPER has a INNER RING suspended in an extremely thick silicon grease,and incased in the damper housing so the damping effect of the friction of the heavy ring trying to move thru the grease works to slow accelleration of the innner ring and absorbs the shock loads from the crank flexing at all rpms as the ring moves inside the damper to absorb the frequency changes

naturally youll need to sellect the correct one for your particular application, and PROVIDED you DON,T GET STUPID and use A HAMMER to install them, that might BIND the outer housing to the inner ring rather than the correct installation tool,the fluid dampers tend to work really well

 

http://store.summitracing.com/partdetail.asp?autofilter=1&part=FLU%2D620101&N=700+400296+300615+115&autoview=sku

 

 

the RATTLER type uses ROLLER WIEGHTS in the HOUSING rather than a thick fluid and a ring

 

Effective balancing from a name you can trust.

 

These Rattler torsional vibration absorbers by TCI are pendulum absorbers developed to control amplitudes of vibration and angle of crankshaft twist like no other design. Their ability to absorb, rather than dampen, is the key to their success. The Rattlers are effective for the entire rpm range, and they extend crankshaft and bearing life. The Rattlers also allow the engine to run more smoothly, which can potentially increase valvetrain stability and life. Their design does not utilize viscous fluids, and they require virtually no maintenance. You can always depend on the Rattlers' timing marks to be correct, because they're etched onto the body and cannot move relative to crankshaft centerline. The Rattlers are also lighter in weight than most units of the same size and material construction, plus they're SFI 18.1 certified

 

http://store.summitracing.com/egnsearch.asp?N=700+115+304451&D=304451

 

 

PERSONALLY I PREFER THE FLUID DAMPER DESIGN BUT BOTH WORK, and SCAT CRANKS THINKS THE RATTLER DESIGNS SUPERIOR,

BOTH have the timing marks clearly marked

 

 

 

this may help

 

http://www.digitalcorvettes.com/forums/showthread.php?t=80373&highlight=damper

 

http://www.digitalcorvettes.com/forums/showthread.php?t=89586

[BillZ260]

I am almost embarrassed to post the issue. I went out yesterday to review the situation and with in about 10 seconds, I recognized the issue...

 

The timing light pickup was clipped around #3...

 

Still running hotter than it should after about 15 min on the road, but reading my notes this morning tells me I have some more ajustments to try on the timing now that I know I have everything lined up

 

Thanks for the dampner info Grumpy.

[grumpyvette]

I am almost embarrassed to post the issue. I went out yesterday to review the situation and with in about 10 seconds, I recognized the issue...

 

The timing light pickup was clipped around #3...

 

 

 

I thought of that....before I posted, then said......NAAAA thats way too obvious as a cause to be missed......why even bring that up...like they say, NEVER ASSUME ANYTHING

[pparaska]

Glad you found it Bill.

 

BTW, the Rattler as an added benefit - it's a conversation starter. Pull into a local cruise in, turn off the engine and it "rattles" as the engine stops. Then people will come over and let you know there's something rattling when you stop the engine. .