Big Single Build

[boostedsohc]

So what I meant, and maybe I wrote it wrong, was I don't suggest using RTV in suction or pressurized areas of the oil system.

Yes, the OEM seals the oil pan with RTV. I did the same when I resealed my engine. As long as it's used correctly, there's no problem there.

I have honestly forgotten how the oil pick-up is installed onto the oil pump. Does it have an o-ring in the receiver hole of the pump, or dies it rely solely on the flange and the seal between the flange and the pump?

RockAuto lists the oil pump screen by Sealed Power (PN 22415048) for $30.79. They list only 4 remaining. I don't know if that is all there is left, or that is all they have in stock before they re-order.

For matching machined surfaces that are to be sealed to each other, I prefer anaerobic sealant.

The oil pickup tube having a thin layer of RTV behind the gasket promotes better sealing of the two surfaces. Also since the RTV is resistant to oil, it is suitable to use in this area. In the 6G72 manual, they recommend a thin layer of RTV. The oil pickup tube relies on the gasket, there isn't an o-ring of sort.

More progress made... Warning! NOTHING IS SET IN STONE AT THIS VERY MOMENT.

I didn't bolt the oil pan down yet because I am missing quite a number of oil pan bolts, so I need to order a new set. I put a few bolts in for now.
I didn't install my head gaskets because my head gaskets are not thick enough. The piston to head clearance is not met with the OEM gaskets, so I have to order custom Cometic head gaskets with a custom thickness.
Now that is out of the way:
Distributor shield:







And wire wheeled a few bolts. I got the oil pump seal to finally work without binding. I sealed the oil pan with RTV black, used a fairly tall, thick bead and let it set up for about 10 minutes before putting the oil pan on. I set the oil pan on the seal for a good 10 minutes before putting a few bolts into the pan. So far, so good, it's coming along, just taking my time, there isn't any rush on this. I didn't torque the rear cam gear yet because I need to take it off and install the newly painted distributor shield then put the cam gear on. I do realize that I am probably going to need to add some teflon tape to the sandwich plate plugs' threads and reinstall in the sandwich plate.

[Sundance 6g72]

Im curious about the headgasket issue? Ive never heard of the OEM not working out BUT I also know nothing about piston to head/valve clearances either.

I am leary about cometic gaskets. I have not heard very many good things about their 6g72 options.

[Ondonti]

Im curious about the headgasket issue? Ive never heard of the OEM not working out BUT I also know nothing about piston to head/valve clearances either.

I am leary about cometic gaskets. I have not heard very many good things about their 6g72 options.

I would like to know what diameter it is. I ran a 95mm cometic gasket when my bore was more like 93.5 and i wish the gasket was smaller since that hurts sealing ability when there is no reason to have that extra diameter.

[boostedsohc]

The pistons protrude from the block deck .020" when they are fully extended which is fine, however, the OEM MLS gasket is .025" thickness not crushed, when it crushes, it will be approximately .023" thick. The machinist recommended at least a .040" thick head gasket set. The diameter of the cylinder bores currently are 91.65mm if I recall. OEM gasket is a 91.1mm.

The pistons hit the heads, the valves don't hit the pistons though.

I also didn't install the heads because I need a head alignment dowel for the one side of the block.

[Sundance 6g72]

Just to be specific, what oem headgaskets were you trying? Do you know if there is a difference between oem SOHC and the DOHC MLS gaskets as far as thickness goes?

[boostedsohc]

Just to be specific, what oem headgaskets were you trying? Do you know if there is a difference between oem SOHC and the DOHC MLS gaskets as far as thickness goes?

I measured my SOHC OEM gaskets and came up with this measurement. Are the DOHC and SOHC the same? I didn't think they line up?

[Sundance 6g72]

There is some controversy over whether they work or not but I know Brent (ondonti) is a big fan of them and has used them.
I'm sure he will chime in

[Ondonti]

I don't think turbo MLS gaskets are that thin. The weird OEM style MLS gaskets that are thin are not what I have ever seen anyone run. I have seen a 6g72 that had a set, it was a mitsubishi sohc I think.

From what I have recently learned, SOHC headgaskets have 1 passage that does not line up for a DOHC setup (which you can fix if you really want to when using composite gaskets) but DOHC still works on a SOHC, barely.

If you want an OEM gasket, use a turbo gasket. They are not 91.1 mm even though the piston is. They have room for OEM approved overbores etc.

[boostedsohc]

So a little progress I suppose. Tonight was an experiment night. I wanted to see how much the head gasket that I had from the OEM kit would compress. This gasket is made of a composite paper, totally not ideal for my application, but I figured test with the OEM stuff. So the gasket is .030" thick, pistons protrude ~.020" off the block deck. I wanted to see how close the piston gets to the head.

I proceeded to use the ARP lube on the head bolts, nuts, and insides of washers. Put the head gasket on, put the head on. Tightened in the given order from ARP to first 35 ft/lbs, then 60 ft/lbs and finally 105 ft/lbs. I rotated the crank a few times to see how much resistance I had on the rotating assembly and had some on cylinder 1 but for the most part, normal across the cylinders. I then unbolted the head and removed the hardware and head. I took the head gasket off and measured it's thickness. The thickness was .029" which is not too shabby for a paper composite head gasket. The head showed no signs of piston contact, it did show some signs of compression of air though and the piston circles were clear on the head.

So .030" works, however, the paper composite gasket I am not sure is the ticket for my application. I need an MLS gasket. I am also going to go with a slightly thicker gasket, most likely a .045" thick gasket to maintain the squish area for combustion as well as provide enough head gasket thickness in the event the connecting rods lengthen their travel in the event of heat.

[Sundance 6g72]

I wonder if OEM MLS is what you are looking for.

[boostedsohc]

I wonder if OEM MLS is what you are looking for.

Yea, unfortunately the vendor I was trying to get in contact refuses to respond. I called them and they picked up but then they said send them an email and I have sent many and to no avail, nothing. I have to put the build on a short hold because I am going on a trip next week and also another trip in June so I have to save up for that.

[Reaper1]

This might have already been covered and I don't remember: why are your pistons proud of the block's deck? Is the block shaved that much? Were the piston crowns made that thick? Were the piston pin holes too low? Were the rods too long? Different crank?

I know...lots of questions. I'm just wondering why as it really doesn't serve a purpose in this application.

[boostedsohc]

This might have already been covered and I don't remember: why are your pistons proud of the block's deck? Is the block shaved that much? Were the piston crowns made that thick? Were the piston pin holes too low? Were the rods too long? Different crank?

I know...lots of questions. I'm just wondering why as it really doesn't serve a purpose in this application.

The pistons have a thicker crown due to the deeper valve reliefs to maintain piston/valve clearances. The machinist did not need to machine much of the deck as the deck was quite straight to begin with, mainly to shave the deck to have a clean and smooth surface.

The machinist recommended a little thicker head gaskets because the piston/head clearance is pretty small and as the engine is turning and heating up, expansion happens and the pistons could touch the heads. He's erring on the side of caution because it's a fairly pricey little setup going on right now. I'd hate for the pistons to hit the heads, any number of problems could occur.

[2.216VTurbo]

Yea, unfortunately the vendor I was trying to get in contact refuses to respond. I called them and they picked up but then they said send them an email and I have sent many and to no avail, nothing. I have to put the build on a short hold because I am going on a trip next week and also another trip in June so I have to save up for that.

Any chance these are what you need? I bought a stack of Mopar gaskets last year and they were with them. Since I don't have any V6 stuff A(Mopar anyway) I've never bothered to see what they fit. I'd let em go for shipping cost only, they are definitely MLS gaskets...

[Ondonti]

Alan, those look like gaskets from a 3.3/3.8 because of the rocker valley sealing area on each side (only familiar with 3.8/4.2L ford pushrod engines).

Get OEM mitsu from an online mitsubishi dealer like Cherry Hill if you really need to. There is even a 3si discount I believe.

But I would suggest milling down the piston tops so you can use any headgasket you want. Needing a deep valve pocket does NOT require having the piston be taller. That is asinine.

I would also not use an OEM paper gasket, the only paper gasket I would use is the composite Felpro. .054 Cometic is what I used on my built motor and that shortblock possibly has the same problem as you but thats only because I ordered the pistons with that headgasket thickness in mind.

[wallace]

On the headgaskets, why not buy two sets of oem mls and disassemble them and combine to make the thickness you need?

[Ondonti]

On the headgaskets, why not buy two sets of oem mls and disassemble them and combine to make the thickness you need?

There are different OEM MLS and he has the junky ones that nobody uses. Those are much thinner.

[boostedsohc]

Come to find out the block deck was milled more than I thought... maybe a mistake? Also, come to find out that these are the DOHC gaskets which are MLS and they line up perfectly on just one head, the other head they don't line up perfectly. The block deck being milled a little more isn't a big deal so long as I can just pinpoint a little thicker of a head gasket set I will be set.

Ondonti, can you give me some clues where you get your gaskets? Cometic refuses to help me out and wants to charge me over 240 a gasket set which is insane.

[Sundance 6g72]

what part does not line up on the one side? If i remember right, it lines up but is not perfect is all.

[boostedsohc]

what part does not line up on the one side? If i remember right, it lines up but is not perfect is all.

Oil galleys and water galleys dont line up perfectly. Some of the gasket covers a water galley. I am sure I could cut the gasket to fit it but I would rather just get the right ones.