New K Motor Head Bolts, Only 7 In Australia!

[luk3333]

Half way through building up my 5K and I'm trying to source some new headbolts but having a fair bit of difficulty. I went to Toyota and there are apparently only 7 new bolts in Australia, so I didn't even ask for a price. ARP doesn't list anything. I went to my local engine shop and they called up 4 or 5 suppliers and none of them listed them. I've searched Precision intl and ebay, no luck. I then went to an engineering fastening shop and the best he could do was the same M10x1.25, 100mm long but Grade 8.8 and without the 10mm shoulder at the top for $13 a bolt. $130 for a set of bolts that I don't know have a high enough tensile strength seemed a bit expensive.

 

When I swapped the head gasket on my 4K I rounded up a set of healthy looking bolts by mixing and matching from the engine in the car and a spare. Would my best option now be to just go pinch those ones out of the 4K?

 

Also, Toyota said that a K motor has 9 head bolts of one part number and 1 bolt has a different part number but they all looked the same to me...

[B.L.Z.BUB]

You could try a forklift parts place. Some Toyota forklifts use a 5K engine.

 

Other Toyotas that use them: http://www.toyodiy.com/parts/xref?s=90910-02069%09&mG=on

Edited September 2, 2013 by B.L.Z.BUB

[luk3333]

Wouldn't they have just ordered them through toyota though?

[ATOYOTA]

Performance Wholesale in Underwood helped me out with my weird engine, they know their shit.

 

Grab a set of verniers and call them up with the following measurements:

Depth of thread in block

How far down past the deck the threads start

Thickness of head gasket

Thickness of head

How much clearance is above the top of the bolt (rockers, distributor nose etc.)

And of course the thread pitch

 

They have a wide range of ARP studs/bolts and have all the measurements on file. They do shipping too.

[B.L.Z.BUB]

Wouldn't they have just ordered them through toyota though?

 

They may have some in stock. Might be worth a try. Just throwing it out there.

[kickn5k]

For ARP's you need two 4age half sets for a K(can't remember if its the long or short ones though).

I've got the part numbers for the correct studs, washers and nuts at home. I'll pm them to you later tonight. Way overkill on a stock(ish) K though.

 

Stu.

Edited September 2, 2013 by kickn5k

[Banjo]

Hi Luke,

Found these ARP part numbers on a KP Starlet website forum.

 

"Arp head studs to suit k series engine are as follows

 

AM5.000-1LB.

Headstuds 10 required

AMW750N.

Headstud washers or you can use your origional toyota ones.10 required.

AMN12-1.

Headstud nuts you guessed it 10 required. "

 

Agree with Stuart regarding total over kill, and expensive, unless you are running very high compressions, and keep blowing head gaskets, after doing all the right things with head & block deck levels, & high performance head gasket.

 

Cheers Banjo

[luk3333]

Well, I didn't really want to fork out for ARP head studs but I was looking for any options. How much is a set of ARP studs? Do you think used standard head bolts would be safe for a 10.5-> 11 CR 5k?

 

Edit: Thanks for the help :)

Edited September 2, 2013 by luk3333

[Banjo]

Hi Luke,

I think you should be fine with standard head bolts, as long as you take all the precautions regarding good head / block seal.

 

I've found over the years there are no short cuts to a good top cylinder block seal. As long as the top of your block has been skimmed to be dead level & the head likewise, the best head gasket you can afford, and it your case a set of new head bolts. I wouldn't be risking using second hand head bolts, with unknown previous life & probably 30 years of use to boot.

 

The trap is not doing your homework with the head bolts before fitting the head. Clean out the threads in the block scrupulously. Put some light sewing machine oil onto a head bolt thread, and with the large thick head bolt washer fitted, and no head fitted, screw the bolt right to the bottom of the block threaded hole. Measure the distance vertically between the top of the block deck & the underside of the thick washer. This dimension should always be less by at least 3-4mm, than the thickness of the head where the bolts fit, plus the head gasket thickness. The danger when decking the block & skimming the head is that the bolts will bottom in the block. I always put a bit of engine oil on the top of the thick head bolt washers to reduce the rotational torsional forces on the bolt, when tensioning the head down. And never fit bolts without those thick washers ! I once had a 4K where the head had been shaved so many times the head bolt was nearly at the bottom of the block threaded hole. Not wanting to grind the bottom of the head bolts to shorten them, I got ten (10) x stainless steel washers, about 1-2mm thick, and fitted them under the thick steel washers. This stopped the bolts bottoming, but had the result that the torsional forces in tensioning the head bolts was greating reduced, as the slipage between washers was less that the friction between the top of the thick washer & the underside of the bolt head.

 

Cheers Banjo

Edited September 2, 2013 by Banjo

[Trev]

Toyota hex bolts are reusable, is the cap screws that you have to worry about. Just inspect the ones you have for stretch.

[Taz_Rx]

You could try a forklift parts place. Some Toyota forklifts use a 5K engine.

 

Other Toyotas that use them: http://www.toyodiy.com/parts/xref?s=90910-02069%09&mG=on

 

5k's use torque to yield bolts standard, so maybe not the best option as if you ever take the head off again you'll just end up in the same boat.

[altezzaclub]

Also, Toyota said that a K motor has 9 head bolts of one part number and 1 bolt has a different part number but they all looked the same to me..

Some motors had one thinner bolt as they used that chamber to pump oil up to the head, but I didn't think K's had that.