RV8 exhaust manifold bolts - torque setting

[Graham]

Hi, all just picked up a set of arp bolts and nordlocks from ACT for the chim, but cant find a torque setting for the exhaust manifold bolts..


anyone have a setting ?

cheers
G

[NTEL]

Till it feels right

[Graham]

NTEL said:

Till it feels right

lol I tried that but they went very tight then very loose and all fell out, with lots of bits of alloy in the threads lol

[carsy]

That does soud very much like you may have stripped the threads within the head. Depending on which one it is its not necessarily the end of the world. The threads are only comparatively soft alluminium. To make this worse they can be in poor condition due to corrosion and general wear and tear if the bolts have been in and out a fair few times. If you are looky you will be able to get a longer bolt in to pick up on good unused threads deeper in the head. You will only need a few threads to engage for it to tighten.

Ultimately it will need helicoiling. This however will need the heads to come off.

[Graham]

carsy said:

That does soud very much like you may have stripped the threads within the head. Depending on which one it is its not necessarily the end of the world. The threads are only comparatively soft alluminium. To make this worse they can be in poor condition due to corrosion and general wear and tear if the bolts have been in and out a fair few times. If you are looky you will be able to get a longer bolt in to pick up on good unused threads deeper in the head. You will only need a few threads to engage for it to tighten.

Ultimately it will need helicoiling. This however will need the heads to come off.

lol, that was a joke... explaining why I wanted the torque settings so that doesnt happen

cheers

G

[carsy]

You had me feeling sorry for you there.

No idea what the torque value is, sorry, i just tighten them.

[Graham]

carsy said:

You had me feeling sorry for you there.

No idea what the torque value is, sorry, i just tighten them.

I'll admit I usually do the same, and i've never managed to strip one yet or have one come loose, but thought as I'd gone to the trouble of nordlocks and arp bolts with nice sharp looking threads I'd try and do it by the book.. but non of the books I have help...


if it make you feel better I have just had to drill and helicoil 2 threads in the head of my disco after a couple of studs snapped... that was a bast**d with the head in situ...

[roseytvr]

15lbft. But you can't get a torque wrench on many of them and not many wrenches have that low a setting. I was told"2 figures on a spanner" and that works for me with arp and nordlocks

[Graham]

Ta motor is on the bench and i have some spanner attatchments for my torque wrench

So should be good to go

[Graham]

Bugger sand blasted the headers to ckean them uptoday in prep for paint and have a crack in one where the tubes meet the collector grrrr

[portzi]

Graham said:

Bugger sand blasted the headers to ckean them uptoday in prep for paint and have a crack in one where the tubes meet the collector grrrr

As a matter of interest Graham what Heat resistant paint have you opted for, as there are quite afew on the market, claiming to be "High temp" ?

Mark

[Graham]

Not 100% but probably por15

[chris1972]

I used POR20 on my manifolds. It is specifically designed for high temp applications (more so than POR15). Meant to be good for 1400 degs F. Only time were tell!

[Graham]

Schoolboy error I meant por 20 not por 15... I did the chassis with por15 after shotblasting and hot zinc spraying and it seems good.

I've also started painting the truck chassis with it and might do my disco chassis too...

[EGB]

To help for what it's worth knowing. To help loosen manifold bolts, extract from good old US of A. Mech Magazine. 1/4 force needed compared with WD 40. No more sheared bolts, hope!
Worth a, try at home.

PB Blaster=ok. A 50/50 mix of acetone & ATF=Best Ever! Here's the cold, hard facts from the April/May 2007 edition of Machinist's Workshop. They did a test of penetrating oils where they measured the force required to loosen rusty test devices. Buy the issue if you want to see how they did the test. The results reported were interesting. The lower the number of pounds the better.

Penetrating oil . Average load .. Price per fluid ounce
None ................. 516 pounds .
WD-40 .............. 238 pounds .. $0.25
PB Blaster ......... 214 pounds .. $0.35
Liquid Wrench ... 127 pounds .. $0.21
Kano Kroil ........ 106 pounds .. $0.75
ATF-Acetone mix.. 53 pounds .. $0.10 50/50 mix

ATF is Automatic Transmission Fluid.
8oz can of Kano Kroil on Ebay.

Edited by EGB on Sunday 28th April 14:44