Torque (overtorquing) question for engine builders

OK...I'm an idiot. I mis-read the required torque for the ARP rod bolts that came with my Eagle H-beams (there was a list of several torques for different bolts and I bit off on the wrong one).

Long story short, I initially torqued several of the rod bolts to 75ft/lbs when it was supposed to be 43. I caught the mistake, pulled the bolts and checked for obvious stretching and then re-installed to the correct spec.

I know that the real answer is that the bolts should be replaced...but I don't have new ones and the motor needs to go in this weekend....I think they probably aren't significantly damaged and should hold like new.

Soooo...do you think this will be a problem likely to cause bolt failure and engine loss (ie...replace the bolts dumbass)...or would you say don't worry?

frumby Wrote:
-------------------------------------------------------
> OK...I'm an idiot. I mis-read the required torque
> for the ARP rod bolts that came with my Eagle
> H-beams (there was a list of several torques for
> different bolts and I bit off on the wrong one).
>
> Long story short, I initially torqued several of
> the rod bolts to 75ft/lbs when it was supposed to
> be 43. I caught the mistake, pulled the bolts and
> checked for obvious stretching and then
> re-installed to the correct spec.
>
> I know that the real answer is that the bolts
> should be replaced...but I don't have new ones and
> the motor needs to go in this weekend....I think
> they probably aren't significantly damaged and
> should hold like new.
>
> Soooo...do you think this will be a problem likely
> to cause bolt failure and engine loss
> (ie...replace the bolts dumbass)...or would you
> say don't worry?

What specific bolt are they?
I have 3/8ths and 7/16ths in stock.

If they have stretched more than .006 (which you don't know unless you measured with a mike beore they went in, and can check their current length accurately) they will not stay tight.

DO THE RIGHT THING----you gotta get that thing together AND SELL IT.


What are you going to do to prime the oiling system before you fire it up?
What did you conclude the last failure was from???

(PS I have some shiney bits waiting here with your name on them)

---

John Vanlandingham
Sleezattle, WA, USA

Vive le Prole-le-ralliat

www.rallyrace.net/jvab
CALL +1 206 431-9696
Remember! Pacific Standard Time
is 3 hours behind Eastern Standard Time.

Me like SHINY BITS!

Last failure was most likely due to oil pressure that was too high. I used an hot rod trick (shimming the oil pump relief valve slightly). Oil press was really high, and that seems to have resulted in most of the oil going to the valve cover, and then starving the bearings. I would have never imagined that...but when looking at the motor it was clearly an oil starvation problem to all the bearings in the motor. Then I remembered seeing an unusual amount of oil on top of the valve cover (like a cup). Seemed odd at the time, but the only place it could have come from was the oil cap which was tight and had never leaked before.

I need this thing to hold up so I can sell it and work the Xratty...but time is very short with a demanding day job, and a baby and wife at home...you know the drill. Always seems like I'm down to the wire putting these things together, and that bit me last time. I'll get a mike and check the stretch accurately. I can still put the motor in and just leave off the pan/transfer case and exhaust until I get this straight.

What's waiting for me john? Let me know and I'll get you what you need.

New bolts ordered...I'm not screwing with it!

frumby Wrote:
-------------------------------------------------------
> Me like SHINY BITS!
>
> Last failure was most likely due to oil pressure
> that was too high.

Most likely??
and TOO HIGH??

Pilot, check your oxygen supply....






I used an hot rod trick
> (shimming the oil pump relief valve slightly).
> Oil press was really high, and that seems to have
> resulted in most of the oil going to the valve
> cover, and then starving the bearings.

How high was it?


HOW DID YOU PRIME THE OIL SYSTEM BEFORE START UP????


>
> What's waiting for me john? Let me know and I'll
> get you what you need.

I'll post piccies.
>

---

John Vanlandingham
Sleezattle, WA, USA

Vive le Prole-le-ralliat

www.rallyrace.net/jvab
CALL +1 206 431-9696
Remember! Pacific Standard Time
is 3 hours behind Eastern Standard Time.

Better yet John, how do you recommend to do so?
I have always pulled all the spark plugs wires and cranked on it for a minute or two.

---

Grant Hughes

http://buschurforums.com/forum/showthread.php?t=19357&highlight=priming

General concensus in the DSM community is that you don't need to prime the oil pump. Major engine builders such as Buschur Racing don't do it, and they don't pull wires or anything...start the motor right up. I had lots of pressure as soon as the motor fired.

I did use TONS of engine assembly lube on all surfaces, and liberally coated cylinders etc.

As far as 'most likely too high' that's because I am an engine building newb and I don't have the guages I should have... Stock guage 90% pegged when it usually sat at 1/2.

I want to build the XRATTY right...it'll have the right stuff (at least eventually).

Man...my jet doesn't even have an oil pressure guage...just an oil pressure light that tells me my one engine is about to fail and I'm probably going to have to eject!

> > Last failure was most likely due to oil
> pressure
> > that was too high.
>
> Most likely??
> and TOO HIGH??
>
> Pilot, check your oxygen supply....
>
Hey John,
I saw the oil out of Jason's valve cover at BRS, and compared notes with Jason; I had the same thing happen many years back: bottom end starved of oil on the first stage after a rebuild with a shimmed pressure relief valve with new gears and no oil pressure gage hooked up.

One recommended mod to Chevy Vega engines for race use was to put a flow restrictor in the oil passage to the head for high RPM use; otherwise the head got too much oil and the crankcase too little.

Pre-oiling IS a good idea. Easy on an engine with a distributor driven pump; but on our Mitsu 2.6L, there is no way to do it short of cranking the engine without plugs. Dunno on Jason's engine.

Regards,
Mark B.

frumby Wrote:
-------------------------------------------------------
> Buschur Racing don't do it, and
> they don't pull wires or anything...start the
> motor right up. I had lots of pressure as soon as
> the motor fired.

One of the worst built professional engines I've seen was a Buschur one.

---

Grant Hughes

I prime my oil pump by spinning it with a drill. Wrrrrr *poof* Pressure! I dont like the pull the coil turn the key trick because the motor is still spinning before the oil pressure is built up and before the oil gets to everywhere its supposed to be. When you spin just the pump to build pressure first, oil gets everywhere and then startup is just like a normal startup with how long it takes to build pressure.

Good thing to order new bolts. Like John said, the actual stretch is very minimal, but has a large effect on the bolt strength. The fancy way to torque rod bolts is with a stretch gauge, and you just go by the bolt stretch and no tq readings at all.



Edited 1 time(s). Last edit at 01/25/2008 06:05PM by Carl S.

Thanks all. Lotsa great info from you guys.

There really isn't a way to crank the oil pump. It runs off the timing belt...and you can bet that I'm installing that before dropping the motor in the bay.

Mark...I wasn't able to come up with a better reason for the failure. I could be wrong on the high oil pressure, but after hearing of your story (that was exactly the same as mine), along with the other symptoms and all bearings trashed it really seems to be the best guess. You can be sure those shims came out!

Mark are you going to be at Sandblast?

As a rule of thumb, our knuckle draggin NASCAR relatives figure 10lbs of oil press for every 1000 rpm used.

I would never fire an engine with a dry oil pump personally. If you have lube on the bearings, cam and what not, spinning a no-spark engine shouldn't hurt anything. I've seen many Fords and Buicks that would never prime a new pump, no matter how long it ran. The gears had to be packed with a light grease first.

I never noticed it mentioned with Jason's motor, but any chance a bearing shell got put in upside down ??

Gene

I do have my oil pumps packed with light grease...nice call though. It builds pressure immediately.

No, I was careful about the bearing shells, and the bearing that ultimately failed completely was a rod bearing, and they are the same top and bottom for this motor. Good call though...that would do it for sure.

NoCoast Wrote:
-------------------------------------------------------
> Better yet John, how do you recommend to do so?
> I have always pulled all the spark plugs wires and
> cranked on it for a minute or two.

And that's the worst possible thing you can do.
Low speed, no pressure= death to bearings.

Pull the dizzy and stick a deep socket and some exentions to engage the oil pump drive if you can.
Spin the auxiliary shaft itself if, like a Volvo the dizzy doesn't run the pump.


Spin till you fill the lines and see oil at the top end flowing good, drop dizzy in or replace belt and fire it up.
>
> Grant Hughes
> www.nocoastmotorsports.net
> Denver, CO

---

John Vanlandingham
Sleezattle, WA, USA

Vive le Prole-le-ralliat

www.rallyrace.net/jvab
CALL +1 206 431-9696
Remember! Pacific Standard Time
is 3 hours behind Eastern Standard Time.

Yes, Jason, I'll be at Sandblast doing tech and whatever needs done. Not racing. Hope to see you there!

Mark B.