ARP Rod Bolt Torque
Turbo Mini Forums

Hey all

Getting close to torque up the rod bolts time.

Do you just use a torque setting as recommended in the Metro haynes manual? Or is the torque required lower due to the moly lube they give you? Or higher to stretch the bolts more??

Any input welcomed!

some may argue tom but torque the bolts up to the settings in the book.

and thats it!

molly lube slightley reduces friction around 3 to 5ftlb so some apply less torque for this

but you cant be sure! this is so using the sort of wrenches we use around this figure

so whack them up to the book figures top setting

i would suggest in going up in two or three stages say 30 40 and then the final setting............. this is the way to go

these bolts do stretch but only microns.

Edited by BENROSS on 28th Apr, 2005.

ARP quote 40 ft/lb for their head studs. The material is far superior to the standard stuff, so i guess there isn't as much stretch involved ??
I did mine to 40 ft/lb with the grease last June, the engine is still running now with no problems.

Phil.

WWW.TURBO-MINI.COM

I was adveiced 40lbs WITH the correct lube, and 45lbs with regular oil... I haven't started my engine yet, but I hope it's OK :)

Yep - use the ARP reccomended figures... They are on their website.

Check the ARP figures and stick to them. I have seven good s/h ARP rod bolts and one stretched one. They are of extremely good material, it simply stretches and stretches... BUT THEY DO STRETCH if you go beyond the recommandations. It appears the the chap who did the assembly on this said engine were not conserned about settings, he had torqued the ARP head studs to 70 lbs just to make sure that "gasket wont blow".

From the ARP website-

206-6001 Part Number (A Series Rod Bolts)

Torque - 50 ft/lb using ARP Moly Lube

Stretch - 0.0067" (6.7 thou).

Also from the ARP site. In particular, interested in the bit that says the ARP stuff should be torqued and loosened 5 times before final torquing?? Any comments??

"Using A Torque Wrench
If the stretch method cannot be used in a particular installation, and the fasteners must be installed by torque alone, there are certain factors that should be taken into account. ARP® research has verified the following “rules” pertaining to use of a torque wrench:

1. The friction factor changes from one application to the next. That is, the friction is at its highest value when the fastener is first tightened. Each additional time the fastener is torqued and loosened, this value gets smaller. Eventually the friction levels out and becomes constant for all following repetitions. Therefore, new fasteners should be tightened and loosened through several cycles before applying final torque. The number of times depends on the lubricant. For all situations where ARP® lubricants are used, five cycles are required before final torquing.

2. The lubricant used is the main factor in determining friction, and therefore, the torque for a particular installation. Motor oil is a commonly used lubricant because of it’s ready availability. If less friction is desired in order to install the fasteners with less torque, special low friction lubricants are available. With special lubes, the required torque can be reduced as much as 20 to 30 percent. It is important to keep in mind that the reverse is also true. If the torque value has been specified for a particular fastener on the basis of low friction lube, installing the fastener with motor oil will result in insufficient preload; the torque has to be increased to compensate for the extra friction caused by the motor oil.

3. Surface finish is also important. For example, black oxide behaves differently than a polished fastener. It is therefore important to observe the torque recommendations supplied with each fastener.

NOTE: It is possible for even the most expensive of torque wrenches to loose accuracy. We have seen fluctuations of as much as ten (10) foot pounds of torque from wrench to wrench. Please have your torque wrench checked periodically for accuracy"

Right now I am REALLY confused.

I thought that the ARP part number for A series rod bolts was 206-6001. However, I dug out the box that mine came in, and it is marked BEB1-08.
Consulting the sheet that came in the box, it says that the torque setting is 38 lb/ft using ARP lube for part number BEB1-08, not 50 lb/ft as the part number 206-6001 suggests.
The Metro haynes manual states 33 lb/ft as rod bolt torque.
I am now unsure what to go for, 38 lb/ft seems favourite but I sure as hell do not want to get this wrong. I think I will have to ring somewhere up on Tuesday to double check unless anyone is 100% sure on the numbers.........

I also had a look at the sheet that came with my head stud kit, that lists 40 lb/ft with ARP lube as some of you have said, so that is the definative answer to that one.

Cheers
Tom

Edited by Tom Fenton on 30th Apr, 2005.

BEB-18: 38lb ft is what I use....

38lbft was what I decided on in the end as well.

All torqued up OK now and turns over nicely.

Next step is to borrow a clock to time the cam in.

Why not buy one tom? You can get some nice cheap ones from Ebay with a magnetic stand. You find lots of uses for it when you have one!

(thought - have you double checked to see there isn't one in your penknife?)

I could do, but I know of at least 5 or 6 at work I can borrow as and when required.......I will have a look though, Machine Mart also do some at reasonable prices.

Penknife McG Mk 1 unfortunately didn't come with a clock and mag stand. Hopefully by Mk2 it will incorporate a full CMM surface mapping feature.

Know what you mean Tom, i can borrowing measuring equipment as and when. always better quality than the stuff i can afford to buy

Also a sad fact, I would like lots of tools I don't have, but at the moment, lack of space to store stuff is more of a problem than anything else.

I've just bought myself a MIG and it is going to need serious garage reorganisation to get it in......

On that subject, anyone got any old pub-gas cylinders knocking about??

Just go to a cash and carry and buy one. think they're £14 full. pretty sure you just then exchange when its empty.

see your local landlord tom thats where i swap mine

but will have to find new source (pub) as hese moving

No. You can still get pure CO2 instead of the mixed gas you talk about.
The place I get it from can still get just CO2, orders it in for me.

The bit that stings about BOC bottles is the £40/year rental for the bottle.

Post excavation.

Just to ad to this I was looking for a torque for my ARP rod bolts. Checked the ARP website and then here and found quite a differance.

I use 200-6207 set (for 998) these are specified as 55 lb ft. Significantly more than the 38 above. The 206-6001 is also specified as such.

It's actually all in Nm, but you can do the conversion from 75Nm

http://arp-bolts.com/pages/technical_torque_metric.shtml

Fastest 998 mini in the world? 13.05 1/4 mile 106mph

http://arp-bolts.com/instructions/206-6002.pdf

Best advice - buy or make a streatch gauge!

Edited by Sprocket on 19th Aug, 2011.

Wil, I just built a 998 with these bolts. Remember that these are bolts, not nuts. Also, the new fancy WRP lube makes stuff different as well.

Thats exactly what my instructions look like, but have a 55 not a 35 on them

Fastest 998 mini in the world? 13.05 1/4 mile 106mph

The instructions that came with my 200-6207 bolts says 45 lbft :)

EDIT: Depends on the lube

45 lbft with the ordinary Moly lube.

55 lbft with the "Ultra Torque" lube.

Edited by Paul S on 19th Aug, 2011.

Saul Bellow - "A great deal of intelligence can be invested in ignorance when the need for illusion is deep."
Stephen Hawking - "The greatest enemy of knowledge is not ignorance, it is the illusion of knowledge."

Mine were the ultra torque lube. 55lbs/ft it was.