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Captdistraction's ST2/GTR build thread Build Thread

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492
387
DFW, TX
The only issue I had with ATI dampers and ARP crank bolt/washer was on a old pushrod R302 block based motor I built. The damper had a huge radius out from the center bolt hole. I had the chamfer the crank bolt's washer on the outside edge so it made direct, flat contact with the face of the damper. I assume the damper was a very tight press fit, I've never messed with 4v engines to this point. Sure looks like the bolt snapped first and then the damper and crank snout twisted. The bolt end in the crank did not twist.
 

racer47

Still winning after 30+ years
392
497
Exp. Type
W2W Racing
Exp. Level
20+ Years
SE WI
I sent your crank pics to a metallurgist friend of mine. He's about 60 yrs old, principle level engr, very smart guy. I asked him if he thinks this is a crankshaft failure or a damper issue.

His exact reply was "This kind of looks like torsional fatigue, fairly low cycle. I would expect something else ran amuck first causing higher than expected torsionals."

He's an understated guy and seldom, if ever, wrong. When he says "this kind of looks like....." that's because he has built in the typical corporate disclaimer. He really means "this is...."

Maybe something happened up top first and then loaded the cam drive gear. This would mean that neither the crank was bad nor that ATI caused the issue.
 

captdistraction

GrumpyRacer
1,954
1,698
Phoenix, Az
Certainly possible but I wonder if it backed off enough and the tension from the fead belt came into play. That belt was very wrapped around a number of things in a way that made it look like it was shredding versus just snapping. I really need to get the other side of the crank with the damper to be sure. Either way I’ll probably throw in a fresh oem damper.

Also food for thought, all the motors in the 2018 FRPP catalog show stock dampers on them now where previously the aluminator XS family wore the ATI
 
1,246
1,243
In the V6L
...Maybe something happened up top first and then loaded the cam drive gear. This would mean that neither the crank was bad nor that ATI caused the issue.

I was thinking about this this morning when I posted in the rebuild thread. Something happened at the crank nose, and the only new info here is the belt being "wrapped around a number of things" that could suggest that maybe it stopped moving and that stopped the crank from turning. It's just hard to imagine a rubber belt being strong enough to do that. Surely it would just start to smoke as the crank pulley spun inside it.
 

captdistraction

GrumpyRacer
1,954
1,698
Phoenix, Az
Crank should win against belt 100.00% of the time. Just curious if the crank damper slipped forward enough the combined stress on the belt and any angular play as it slid off could generate the torsional forces to do this.

<- not a metallurgist. I just break stuff and occasionally sleep at a holiday inn express.
 

racer47

Still winning after 30+ years
392
497
Exp. Type
W2W Racing
Exp. Level
20+ Years
SE WI
Remember that OEMs usually work off the "just good enough" policy. If they put ATIs on the drag cars, thats significant evidence that ATI is in fact better. Ford surely has tested this. Maybe Ford does not think that ATI's are necessary for road racing to meet their durability targets. If the OEM is "good enough" why pay more for ATI? That does not mean that ATI is bad, its just unneeded insurance. Fluid filled balancers have been around for a long time and are on every single purpose built race engine that I can remember seeing in the past 20yrs. I find it hard to believe that ATI is to blame.

Also I would highly recommend against racing any Ford production built short block as bought. They only get the typical "detroit engine balance". They are not balancing rotating assemblies. They just build to target weights and you get what you get. Some are good, some are not and probably none of them are as a good as a real engine machine shop balance job. Buying a Ford built short block is fine but take it somewhere and have it balanced, inspected and reassembled.

arrow-hemi-engine.jpg
 
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492
387
DFW, TX
Crank should win against belt 100.00% of the time. Just curious if the crank damper slipped forward enough the combined stress on the belt and any angular play as it slid off could generate the torsional forces to do this.

<- not a metallurgist. I just break stuff and occasionally sleep at a holiday inn express.

Your crank is already screwed if the damper moves fore and aft at all. The press fit of the damper on the crank and torqued damper bolt must keep it in place or it will just hammer the key. The key in the crank isn't going to do anything to keep it all together for long.

The damper should have been a PITA to press on the snout. If it was easy to install then either the crank's snout was undersized, or the damper was over sized, or a little of both (tolerance stacking).
 

xr7

TMO Addict?
706
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Minnesota
How many hours did you have on this engine when it let go? Any thoughts to opening up the damper for inspection? I have seen a bad damper do amazing damage to an engine. Is this the first engine it was on?
 

captdistraction

GrumpyRacer
1,954
1,698
Phoenix, Az
19ish hours. I didn't log break-in, but have a rough idea of how long it ran.

The damper and crank are making a trip to Ford Performance then to ATI, but while its in my hands I'll press out the crank snout and perhaps open up the damper. It should be a pretty simple piece, just two metal halves on the outer ring with a set of rubber O-rings contained within then bolted to a inner body that holds the press fit on the crank.

I'll know more on the 17th. The new set of lungs from @steveespo arrive on Monday, going to be a blitz to get the car back together.

I've ordered the broken hard brake line, undertray, GT500 radiator fan (radiator looks like it is ok), a lower radiator hose and bumper brackets. The front fascia ripped where the tow hook goes through but otherwise is usable for now and I'll get another one over the summer break, along with a higher flow grille. Still need to order fluids, some sensors and a body harness (as my starter/trans/positive battery harness is literal toast). I don't have an oil cooler for this, the setrab 948 is out of budget right now with everything going on.

Eventually Steve's motor will wear more aggressive heads/cams but for now will run it as is and work towards being a better driver (and dropping as much weight from the car as I can get away with).

Its on the outside chance, but I might be able to get this back together for the NASA march event.
 

captdistraction

GrumpyRacer
1,954
1,698
Phoenix, Az
Have the motor in.

That said here's a semi-comprehensive list of install steps. Think this is spot on? I have evenings (maybe some weekend time, but probably not) until a week from today to get it done. I think its doable as long as there's absolutely no problems along the wayInstall Steps.JPG
 

captdistraction

GrumpyRacer
1,954
1,698
Phoenix, Az
knocked out 4 hours of stuff on the list and hit a few snags:

The primary chains feel a bit tight once they were off the motor and let to sit. When I say tight they didn't immediately pivot freely although hitting them with little engine oil returned them to easy to manipulate. I can't order new chains in time but will replace them.

The upgraded tensioners didn't make it in time, so I've installed the outer motor covers and will do that same time as the chains. (motor wears original early production GT tensioners)

The oem damper was losing its rubber on the inside. To (loosely) quote Sam Jackson: I HAVE HAD IT WITH THESE MOTHERTRUCKING DAMPERS ON THESE MOTHERTRUCKING MOTORS! I've ordered a replacement overnight and will be here tomorrow with any luck.

One VCT actuator broke under its mount (They're sort of a pinch weld/brazing) and I'm waiting on 2 from a local dealer and one from a local parts house. Whoever is first wins (just need one)

Won't have time to wrap the headers again so will save it for the next motor evolution and collect some data to map against its effectiveness. The unwrapped headers looked fine, there was no meaningful degradation of the stainless steel metal.

the motor is painfully dry, but I don't have time to take the cams out and run assembly lube underneath and soak the lash adjusters. That said I'll prime it before firing (wish my accusump was full - any one have thoughts on what I could do to pump oil into it to in-turn prime the motor?).

Finally, I'm debating what to do for oil cooling. I need to buy a setrab 948 but funds don't currently support that move. I can either buy it sooner, but just run one event with the boss water/oil cooler only, or hook up a temporary setrab 915 in the loop. Thoughts?
 

steveespo

Lord knows I'm a Voodoo Child
Moderator
4,008
1,924
Exp. Type
W2W Racing
Exp. Level
10-20 Years
Cookeville TN
knocked out 4 hours of stuff on the list and hit a few snags:

The primary chains feel a bit tight once they were off the motor and let to sit. When I say tight they didn't immediately pivot freely although hitting them with little engine oil returned them to easy to manipulate. I can't order new chains in time but will replace them.

The upgraded tensioners didn't make it in time, so I've installed the outer motor covers and will do that same time as the chains. (motor wears original early production GT tensioners)

The oem damper was losing its rubber on the inside. To (loosely) quote Sam Jackson: I HAVE HAD IT WITH THESE MOTHERTRUCKING DAMPERS ON THESE MOTHERTRUCKING MOTORS! I've ordered a replacement overnight and will be here tomorrow with any luck.

One VCT actuator broke under its mount (They're sort of a pinch weld/brazing) and I'm waiting on 2 from a local dealer and one from a local parts house. Whoever is first wins (just need one)

Won't have time to wrap the headers again so will save it for the next motor evolution and collect some data to map against its effectiveness. The unwrapped headers looked fine, there was no meaningful degradation of the stainless steel metal.

the motor is painfully dry, but I don't have time to take the cams out and run assembly lube underneath and soak the lash adjusters. That said I'll prime it before firing (wish my accusump was full - any one have thoughts on what I could do to pump oil into it to in-turn prime the motor?).

Finally, I'm debating what to do for oil cooling. I need to buy a setrab 948 but funds don't currently support that move. I can either buy it sooner, but just run one event with the boss water/oil cooler only, or hook up a temporary setrab 915 in the loop. Thoughts?

Chris to prime the engine get a garden sprayer and remove tip from the wand. Get a barb fitting to screw into oil pressure sensor port. Get a length of hose to put onto end of wand and onto barb fitting. Secure with worm clamps. Fill sprayer with 5W20 oil and pump up. Hold trigger down and when oil is halfway gone begin turning engine by hand to distribute oil. Top off oil and put sensor back in. Should be good to go. Also put some Rislone or Marvel Mystery oil in through the spark plug holes to lubricate the cylinder walls.



Sent from my iPhone using Tapatalk
 

xr7

TMO Addict?
706
821
Exp. Type
Autocross
Exp. Level
10-20 Years
Minnesota
I would remove the accusump, drain air pressure off, remove the Schrader valve, a little air pressure in the oil side of the accumulator will push piston all the way back. Fill accumulator with oil. Reinstall accumulator, reinstall air valve. Add air pressure to accumulator, put your 1/2" ratchet on the crankshaft, open the accumulator valve & start pulling on the ratchet, pre-lube completed and you didn't have to buy more stuff. Watching out for OPM!
 

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