600 ft GRP Rods

Gotta agree with Nathan, the aluminum rod threads are much weaker than the steel bolts, the GRP statement sounded more like a sales pitch than a technical note.

Using a helicoil insert will vastly increase the aluminum thread strength, a shouldered insert would be even better.

 

If i were you, i would never change whoever is balancing your motors, cuz hes doing a great job, imo, balancing is the main cause of rod breakage other than not tourking them right.

 

So your saying that the majority of the time a rod breaks is because the motor isn't balanced right? So that means no matter where the rod breaks, small end, big end or in the middle, it's a balance issue. I find that hard to believe. if a bolt is in the pan, it's usually because it was left loose and fell out, or, it was left loose and pulled out the threads on the power stroke. Rod breakage has numerous reasons, it depends on where it broke.

 

broken rod

We were at an IHRA nats last year. I pulled the pan in the trailer Sat. nite to check a few rod bearings. I pulled no's 2 & 7, they were perfect. The next day no. 2 rod came through the pan. One bolt was in the pan with the threads on it. I'm convinced I put the cap on backwards and that's what did it. I know they were torqued correctly. Just plain negligence on my part. An expensive mistake, so it can happen even though your positive you didn't do anything wrong; and I've been doing this for over 30 years.
Glenn

 

When GRP said that the bolt would fail before the rod threads I would assume that they were not talking about thread failure, that is the number of threads engaged on both the bolt and the rod should be more than equal to the task of either stretching the bolt shank the correct amount, or conversly overstretching the bolt skank causing failure of the bolt not pulled threads when overloaded.

Of course anything I assume starts with ass so who knows.

Richard Gavle

 

Well I just had a 20 minute conversation with Biller Miller about this last week. Bill said it was critical to do 1 even paced pull, DO NOT DO IT IN STEPS. Stretch gauge for initial assembly and record the torque numbers. Repeat that torque at the track for maintenance (same wrench). When you get back to the shop check the stretch and see what you have. I don't want to mis-quote him so I can't say without going to the shop (to get the number) when he said to throw them away.

 

Soooo using a 24.99 torque wrench from Harbor Freight isn't advisable? Just kidding we use a Mac tools model.

 

Yea, Giannone was pretty addment about the one continues pull on rod bolts also.

Blessings........Ron.

 

Well, I agree the torque wrench should be checked. Once it is it should not be used to overpull tight bolts and put it out of calibration. I would call Brian and ask him about the stretch guage. this is the best way. Aircraft techs do everything by torque wrench. I am always amazed at how some folks treat their precision instrument- the torque wrench.
Dale

 

Warren and Brown wrenches I think come out of the UK.

To add to Mike's tech comments:

Most fasteners are held tight or retain their torque because the the bolt or stud is stretched when torqued, usally within a 60% of the fasteners yeld point. If you dont get the fastener within its yeld point (which varies on grade, type of lubricant, or material type) the spring effect does not maintain torque therefore comes lose.
If you torque to far you permanetly deform the fastener and it will either not tighten because of stretching or snap. Or even worse you dont notice, go out and run and chuck a legg out of bed.

Norbar is another very good wrench.
Cheers

 

Torque Wrenches

Actually, W&B is an Australian company.

http://www.warrenandbrown.com.au/PrecisionTools/home.aspx

Hard to believe the Aussies actually make something good but it's true! I've had one for years and when I finally got around to calibrating it, it was so close it wasn't worth worrying about (but I did). I think the best design aspect is that there is no hidden mechanism and easy to adjust. They are very simple (bit like Aussies I suppose ).

In the Air Force adjustable torque wrenches are checked once every month, and those used for one particular operation are checked every time they are used. Also, we only use a TW within it's 30-80% range, never at either end of it's scale.

I don't know what a Torque Tester would cost, but I'm fairly sure they are super expensive. Best bet would be to have two so that you've got one to use while the other is away being calibrated, or find a calibration shop close by so that you're not without for too long.

Paul.

 

When you tourk your head's do you do it to 140 lb's all at once, good for the goose, good for the gander, and if your using a stretch gage how do you know how much to go to all at once, not to mention how do you make the next round playing with your tourk wrench, KISS! also reread my post i said other than not tourking them right. i rebalanced many a motor that was way out and you would never know it ,but the rods would, it's called make work detail. thats why when i raced i built my own engines and i bought my own engine balancer, IMO it the most critical part of engine building. that it's within 5 grams is crap, it's either perfect or it's not, theirs motors can blowup in .05 seconds to .6.00 seconds, do you think there's a little mouse in the pan unscrewing you rod bolt. Hummmmmmmmmm.

 

Grp rods

Have put my GRP Rods through hell lately & have ran GRPs for 4 seasons now without any issues. I still can't believe they havent been hanging out of the oil pan. I have forked many of them but never broke one. We have had 80 very hard laps on the last set & just out of guilt, cycled them out. We run the 3600 series with 1.600 width @ pin width & use the 2000 ARP bolts. We will continue to run them, even though we are paying regular price.

 

my last post was for alkydragster not james d i hit the wrong post. oopps

 

Gene, I'm still pondering how you generate so much heat step torquing them rods. You sure you wer'nt (prune picker talk) making trips to the refrig while cooling?

Blessings........Ron Clevenger.

 

Ron if you have a temp.gun put it on a bolt and nut in a vice have some one take temp before, then tell me theres no heat, as your tourking bolt to 90 lb's, dry, then put some anti seize on it and do it again. P/S i dont drink anymore, nor smoke, P/S again,Ron, shoulden't you be telling every one whats going on before it's to late?

 

Gene, just poking a little fun at the heat deal. These days I'm a lot slower than days gone by. How about slooooowly making one pull on that rod bolt.

It's not to late until you exhaust that last breath. Eternity is a mighty long time for sure and I spent most of my previous life chasing the wind. Now I just give praise to the one that creates the wind.
My racing ministry (Creekside Racing Ministry) is used to catch those before that last breath...hopefully....in time.

Blessings.........Ron Clevenger.

 

GRP told me the same thing about one slow pull. Being anal I like to tighten each bolt snug to make sure the cap is seated and also to make sure I can turn the wrench far enough to reach torque before I run out of room, then I tighten in one slow pull to torque. This one pull thing works because you are only applying load to one side of the cap {which sits directly under the bolt} while torqing the bolt. Conversly on a head, manifold, etc. where you are compressing a gasket you need to apply torque in steps to avoid distorting the parts during the compression of the gasket, this will cause damaged parts as well as uneven torque. The same holds true for attaching two large parts together where there is no gasket just to a lesser degree.

Just my 2 cents,

RG

 

So, that would hold true for mains too? No gasket. Just curious, really.