I was given some great assistance in determining the type of heads I was using when I supplied a head number to the forum. They were the 10 bolt configuration. I was just about ready to turn fire up my newly rebuilt 3.5L engine when things never went to plan. Water is leaking out between the case and heads, noticed this before cranking it over. I went back to my original inquiry http://www.aulro.com/afvb/technical-chatter/50065-heads-missing-bolts.html to find I have missed one important issue along the way, “[FONT='Verdana','sans-serif']just a matter of the right gaskets but there are two 10 bolt 3.9s”[/FONT][FONT='Verdana','sans-serif']. I have immediately realised I have used a 3.5L gasket, I have stuffed up haven’t I ?[/FONT]
[FONT='Verdana','sans-serif']Considering I want low compression which gasket would you suggest, considering I have a 14 bolt case 3.5L with 10 bolt 3.9L heads? [/FONT] Nearly ready to explode here !!!!!!!!
Your description of where the water is leaking from is a bit vague, can you describe it better or post some pics, might be able to help, then, Regards Frank.
In photo shot 140, hope it's attached, is an image of number one cylinder as standing on the left hand side of the engine bay. Directly below the spark plug is an aluminium tab which if you look close enough has a few drops of coolant running down it.
This is repeated for each cylinder as you can just make out in image 139. this is also the case for both sides, I have no idea what I have done wrong.
Your using a 3.5 block so you`ll use 3.5 gaskets .
Have you used tin head gaskets ?
If you want thicker than factory get a pair of Felpro composite 3.5 gaskets . I can give you their thickness if needed .
The basic makeup of 3.5 and 3.9 gaskets is the same .
They have different thicknesses and the hole/firering is a different diameter but the actual fittment as in around oil passages and coolant gallerys is exactly the same .
From this your choice of gasket is not the reason for your problem .
Couple of things i can think of ...
You will have noticed the dowels that will either be in the head face or block face or both .
It`s possible for them to skew in either surface and not allow the 2 surfaces to meet flatly .
It cound be possible that because you`ve used different heads on a different block that you have too many dowels in it and they are not allwing the 2 surfaces to meet .
It could be the the liquid is from the bolt holes and has been forced out by the bolts .
This can occur if an engine is dismantled with the coolant level too high , it rest in the bottom of the bolt holes and if the holes are not blowen out during assembly the liquid makes it`s way out when the bolts are done up .
I am pretty sure you helped me out with the heads issue last time, this one has me confused. The water appears to be running out in the location of the four(4) bolts on the block which are not being utilised. ie. 10 bolt heads in 14 bolt block.
I am using the felpro composite gasket, but hang on a minute I have missed another important thing, I am using 2 gaskets on each side to reduce compression.
A couple of point.
1 There is NO effective difference between 10 bolt heads and 14 bolt. I have put 10 bolt on my 14 bolt 3.9 with no problems.
2 The head bolt holes in the block are sealed so no water can come out.
3 You put 2 gaskets on? What sort of gaskets? tin?
The way to go would be to use a composite gasket which is about 35 thou thicker than a tin gasket. your tappets may be noisy due to no preload. Dunno whether composites are available for 3.5.
I think the two gaskets are the problem and water is coming out between them.
Regards Philip A
You should be able to suss the dowels by using a feeler gauge without taking it apart .
Was looking on Ebay the other day and there`s a bloke doing copper gaskets . I`m sure they could do around 1mm or a little better . ( my reckoning of what you have ?) I`ll find his contact for you , if you like ?
Could be your twin gaskets , being as their metal one side and fibre the other it shouldn`t really matter though i wouldn`t have thought .
If you pull it apart and find nothing out of the ordinary ( probably have to because of the glyco/coolant ) maybe a bead of high temp silicon around the coolant and oil ports on each would work .
Very sparingly of coarse .
The factory 4.0/4.6 gaskets have a bead so not out of the ordinary .
Some reckon it`s better not to use coolant straight away because the coolant can have an unsealing effect on some gasket types i don`t know if these Felpro are in this mix but the fibre side may be .
Use only 1 head gasket, they are designed to compress and seal between 2 metal surfaces, NOT against one another. Changing the height of the heads above the block surface can cause other problems, because the inlet manifold is machined to fit between the Manifold surfaces of the heads, raising or lowering the height of the heads from the block surface will affect how the inlet manifold mates up. If you lower the head by machining the surface or use a significantly thinner head gasket you are narrowing the distance between the manifold mating surfaces on the heads which means the inlet manifold will sit higher in the V and the front and rear sealing suface of the manifold may not seal properly and the opposite is also true, most machine shops have the formula for what machining of the inlet manifold may be required to get the mainifold to seat correctly, Regards Frank
Happens i`ve got a pair of Felpro a pair of 10 bolts and a 3.5 block .
If it had the wrong number of dowels it seems you`d have noticed sooner as the gap would be large .
I had the thought that the dowels weren`t long enough to line up 2 gaskets and that maybe 1 gaskethad skewed but when i looked you could easily fit 4 gaskets on the dowel height .
Although i can`t see any sign of a raised fire ring on my gaskets as they are used ones , it could be that as Frank suggests though the metal to metal theory doesn`t work because it is all metal to metal because that part of the gasket is all metal .
What i think you need to do and it`s only a suggestion is to ....
Drain the coolant so as it is definately below the lower height of the heads , would be best to remove the bungs from the block to be sure .
This way when you remove the heads there will be no excess coolant to worry about .
If there is a problem with the fire ring/s not squashing enough , i`d expect you find a track of coolant between the 2 gaskets at the base .
I think the reason the coolant is where your finding it at the moment is because of gravity .
It`s coming out of the jackets on each end and meeting in the middle but showing because of gravity .
I think i`ts posssible to use 2 gaskets when you inspect the gaskets you`ll see what happening .
For the rocker post suggestions of Philips and the inlet manifold suggestions of Franks .....
It would pay to check the lifter preload but i don`t think you`ll need to machine the posts
If the block hasn`t been decked and the heads skimmed little by using 2 gaskets and the 10 bolt head all the heights/distances will be near enough to the same as if you used 14 bolt heads and tin gaskets .
The only thing is that if you have a stamped 8.13 or 9.35 block and the pistons are std for those ratios you will have near enough to the same ratio with what you have done .
Can i ask what fine torque your putting on the head bolts ?
The reason i ask is because i had to use above factory recommendation when i used felpro to lower the ratio on a 3.5 but it was around 12 with tin and they had to be more than factory too , i did have to fit some helicoils in that block as well because of it .
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Fossicker
Heads and Gaskets, what can I say ?
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