hey bud,
thanks for your input on an old thread, I had a look at your link and it gives a lot of good info thats much needed. 🙂 I think I'll just be doing just head gaskets since engine is good.
at 100,000km compression spot on around 150/ 160 across all cylinders , no stutter no hesitations.. maybe piston rings
..
Anyway..😅😅 Thanks bud hope you're enjoying your kitty cat

 

I was asked by a fellow member to post how to tighten the heads down. Lets first start off with if you are doing this NEW BOLTS ARE A MUST!!!!! Yes, the old bolts look just fine. But, the bolts are torque to yield bolts. What this means is that as the bolts are tightened, they are stretched. When they stretch, they gain strength. But, what happens is when you release the strain, they don't snap back. So, the next time you go to "stretch them", they may stretch, but their overall strength is most likely going to drop dramatically. So, when you start the car or rev it hard, you may every easily lift the head and create a mess of other issues now. So, once you do this procedure, if you have to remove the bolts, new ones will be required.

You will put a new head gasket on the motor and then place the cylinder head on the engine. You will then drop the 8 bolts into the holes of the head. At this point, the top bolts, number them 5, 1, 3, 7 (starting from front or back does not matter). Now, number the lower row of bolts 6, 2, 4, 8 (starting at the same end of the engine you did for the upper bolts). Install the bolts until they are finger tight. The bolts get tightened in 6 steps, starting with bolt 1, then bolt 2, etc (unless otherwise stated). Once you start a step, complete the step on all 8 bolts before moving to the next step. The head must me installed with as even of pressure being applied as possible. This will ensure the head gaskets gets seated properly.

1) Tighten all bolts to 30 Nm (install mark at some reference on all the bolts using a paint pen or other similar marking device).
2) Tighten all bolts an additional 90 degrees
3) Loosen all bolts 1 full turn (going in reverse order, ie, Start at 8, then 7, then .....)
4) Tighten all bolts to 30 Nm (install mark at some reference on all the bolts using a paint pen or other similar marking device)
5) Tighten all bolts an additional 90 degrees
6) Tighten all bolts an additional 90 degrees (for a total of 180 degrees from the second torquing to 30 Nm).

As you can see, you are not concentrating on what the torque is. You are making the bolt stretch to get rid of any "slop" that may be created as a bolt is stressed.

If there are questions about this, let me know. I have had lots of training on torquing items and why you torque things to key values and why that value is important.

 

Thanks Thermo 🙂

anything else I should be on the lookout for? Things that are prone to fail by your experience and that am better off changing while am in there or gaskets, bolts, leveling the heads and am good to go?

 

XType, well, if you have both heads off, I would tell you to have the heads apart to clean things up and then using a grinding stone, smooth the inside channels of the exhaust and intake ports. That is a cheap thing to do (costs about $30 to do-cost of 3 grinding stones and an 12" extension). This will not dramatically change the shape of your intake/exhaust ports, but, because the surfaces are now smooth, you are going to reduce the laminar boundary which is going to have an effective enlargening off the ports. With the port seemingly bigger, the motor can flow more air and therefore make more power. Now talking tons, but you can probably expect a 20ish HP gain. You want to be greedy, then you oversize the ports some. Granted, that is going to be a $1000 upgrade for the machine work and new valves. But, you could expect to gain a decent amount of power. The big trick with the polishing of the head ports is you need to focus on the inner portion of any bend, not the outside. Yes, it sounds bassackwards, but if you do some reading, you will see where there is a lot of people that state that same thing.

As for things being warped, you should do atleast a metal ruler check for flatness. If you simply had a head gasket fail, then you should be good. If you overheated the engine, then a flatness check is a must. Hopefully you marked the timing chains what side of the motor they came off. You should also find on the chains some different color links. Those discolored links have meanings. In short, the one by itself lines up to a mark on the crankshaft and the 2 that are close to each other should line up to marks on the camshafts. This will set the timing correctly.

 

thanks again Thermo,
just to be clear I should be smoothing out the insides of the intake and exhaust manifolds is that right? I think that's what it translates to in UK terms 🤔 hahaha ..
I appreciate the extra info.. I opted for a full gasket kit as suggested by the other fella , new pump and while at it new oil pan gasket , obviously new head bolts too.
while running tests I had good compression across the 6 cylinders but i did find a bit of oil on the spark plugs so I might have a go at doing the piston rings while the head is out ... they are cheap and well worth having new ones in as I don't plan to remove the head any time soon.
as far as smoothening the inside curves it would actually make sense as that's where the air would bounce to and find more restrictions , as the outer edges would always have the biggest flow route. not backasswards at all bud 😂

Last question i was wrestling with was wether or not anyone anyone got around the whole transfer case issue , I saw you talking about it in a few old posts and I really wanna supercharged this beast somewhrre down the line.

Again thanks for the help 🙏 its very much appreciated

 

XTypeProFiler, yes, you are correct, the exhaust and intake port walls. Make them smooth. Don't need to make them mirror smooth, but getting rid of the rough casing surface will do wonders for power. When I did the heads on my truck, I used a few different shaped grinding stones to do the bulk of the work, then I got a bunch of 60 grit sanding wheels (25mm in diameter). Those will take the uneven surfaces left by the stones and smooth them out. You will end up using up a sanding wheel after about 2 ports. You will find that it just won't be smoothing things out all that well after a bit. For what the wheels cost, you will go through a fair number of them.

As for upgrading the transfer case, no one has really pushed the issue. It seems as if the best thing that has been done is to simply pull the transfer case and get the bearings properly pre-loaded on the rebuild. People don't seem to have issues on the rebuild units when the bearings are installed properly.