V-12 Engine into 308 Build, over on Grassroots

It been at 15 psi for 45 minutes now with no change I can see.....

 

6 hours and all is well.....fingers crossed.....

 

Its 18 hours now and no change on the pressure gauge which seems a very good result. ... so this evening reassembly will begin. I still need to fix the motor mounts and the shifter shaft leak before it goes back in but its cold outside and will be for a few more weeks so I'm not in a huge hurry to be out in the driveway tuning so a few more weeks work is fine I guess.

Funny how my 2-3 week project is what, 3 weeks in? ....and still 3+ weeks from finished. Image Unavailable, Please Login

 

Good to hear. Here's to hoping it stays sealed.

Don't let any superchargers near it.

BTW..what is the compression ratio?

 

10.7CR but the engine software is projecting relatively high cylinder pressures with bmep around 17bar....and then there was the talk of nitrous......

 

Exactly what my 3.5 L 328 is but I am sure BMEP is lower with the cams I have.

 

Great to see this progress. I have copper head gaskets on my 308's so I know about coolant leaks. Don't be afraid to put in one can of something like Bar's leak. JUST ONE CAN. If you over use it, it can start to clog stuff up. But it's basically required with the copper gaskets I have.

 

I thought I would mostly put the engine back together this weekend but saw this Friday

Image Unavailable, Please Login

and I'd lost about 1/4 psi from here

Image Unavailable, Please Login

to here

Image Unavailable, Please Login

The coolant temp sensor I had kind of cobbled sealant into it to get it sitting where I wanted and just forgot to to fix while the heads were off so this isn't a huge surprise and of little concern. This could easily be the 1/4 psi because I'm pretty sure there was next to no air in the system when I capped it so even a small leak should make a pressure drop....but....I decided to fork out $26 for a 5.6mm wifi camera to have a look in the cylinders and it finally arrived this evening.

Image Unavailable, Please Login

No coolant. I will also need to pull the sump cover to replace leaking shifter shaft seals so I'll take a look in there too, just to be sure.

Now, there is another issue I was pretty sure would happen.....aviation sealant . Kind of weird pic as its shot with a the mirror attached and the wide angle lens is also looking around the mirror...but the important part is the sealant

Image Unavailable, Please Login

Its pretty much every bore...need to ponder this a little bit.

 

I'd leave it as is and under pressure a lot longer. If it is trying to leak there it will take 15lbs of pressure a long time to push the sealant out of the way.

I was getting ready to ask if a really good visual had been done. A small leak can take a very long time to show on the pressure gauge especially with that much volume.

 

Its been a week at this point. could run the pressure up to 30 or 45....but I think I['m going to see if I can clean up the sealant a bit, fix the leaking sensor and then redo the pressure test, perhaps at higher pressure. The weather here sucks so I have a few weeks before I'd like it back together for real.....and do a for real leak test

 

Is that at the Siamese of the liners? Or just in general?

I didn't get seepage into the bores when using the sealant. I think the pressure test is pushing the sealant, the design is for a water jacket along the surface of the block and head, air being of smaller molecules is going to permeate where water doesn't, possibly explains the sealant leaks.

 

I don't think it has anything to do with the coolant testing. Its drip coming from the low spot, so 90 degrees to the siamese area. Generally I can see sealant all around the head/cylinder interface and then gravity worked its magic to create a drip off the bottom.

It will burn off I'm sure but my concern is it damaging the rings or flaking off and getting stuck behind the rings which could then damage the cylinder wall before the combustion heat burns it out. I'm leaning to pouring lacquer thinner in it and rolling the crank back and forth slowly to wash it off as its a non-hardening solvent based sealer

 

all better I think

I tried (denatured) ethyl alcohol because I had a gallon and dissolved the stuff just fine in a bench test so I poured some in each hole, rolled the crank, sucked it out and it was clearly dissolving something

Image Unavailable, Please Login

I did it 3 times, then blew it out and put in some wd-40 to coat everything and it looks fine now. I can't really clean above where the rings sweep but I don't think I care about that so I'm calling it good.

Image Unavailable, Please Login

 

Mark, what is the benefit of the aircraft sealant over high temp RTV silicone? I used the latter for the water passages on my head gaskets and no problems so far (short drives every day since October.)

 

Silicone breaks down with exposure to fuel. And many lose their adhesive properties in constant exposure to petroleum products. It also has a film thickness that can create issues in some applications that are dimension critical.

Aviation Permatex has been around forever, is often forgotten but in some applications especially non gasketed machined casting surfaces like oil pans, case half's etc is a really great product.

And unlike 518, clean up is a snap.

 

I'll add that I have seen people use RVT on head gasket, particularly the solid copper ones without issue. When parts are clean so the RTV can bond it seems seal just about anything really well. The only issues I've ever had with it are working fast enough on big items so it hasn't skinned over too much to bond to the mating part or allow the parts to sit flat. The other concern I head about is the stuff oozing out and plugging things up either directly or bits breaking off and ending up where they don't belong...much like the k-seal crap was doing to my small coolant passages. I used RTV to seal the engine to the trans and last assembly I used it with the timing cover gasket and it seemed to fix the small leak I had the last time...but obviously I can't actually credit the rtv with the fix, a correlation is not causation kind of thing but I'll likely use it there again even though it is a big part that takes some time to assemble into place.

 

Ok, enough screwing around, Lincoln (which has been distracting me) pushed back into the corner to wait its turn...i may need to put a cover on it so I stay focused.

Image Unavailable, Please Login

I've been dragging my feet on the timing cover because additional action was required. The last time I assembled I realized once the gasket was glued and most everything torqued that I had bolt location issue. Repairing the heads meant milling them, and that lowered them. Each head has 2 bolts that clamp the timing cover to it....I added them to the TR heads to make the 400 timing cover work and with the heads remilled they got pretty buggered with me trying to get the bolts in

Image Unavailable, Please Login

so today I slipped the cover on and found a drill bit that just fit though the cover holes and made centers match the start of the hole, then switched to the helicoil bit and drilled, making a nice oval

Image Unavailable, Please Login

There were still some threads on the bottom so wen I tapped I used a block to keep things straight and was careful to to let the tap follow the existing bottom threads.

Image Unavailable, Please Login

then coils in, clean it up and ready to actually install the cover

Image Unavailable, Please Login

 

The timing cover is back on and cams timed. Cam covers and intakes tomorrow hopefully.



Image Unavailable, Please Login

 

Its an engine I think....but I still need to pull the sump to fix the shifter leak and figure out the mount mounts...oh and fix the clutch hose.

Image Unavailable, Please Login

 

Shook of the lazy and got the gaskets and new seals for the shift shift ordered....hopefully that will solve the oil puddle on the floor. It seems to be holding 2-3 quarts in the sump rather than pumping it all back to the tank as I'd hoped....I guess its down where I placed the outlets for the returns and maybe pump height. But if needing a working seal on the shifter just like stock is the worst of the oiling problems I'll call it a win I suppose.

 

Design development engines can be a right pain in the arse.
Any of the leaks around -AN fittings? I ask because that's one fitting style that many mfg screw up. XRP and aeromotive give the least problems but alas not very interchangable... Thankfully Teflon paste exists.

 

The AN fittings have not given me any problems so far, that rest of though is reminding me or this

 

Six, 8, 10, who cares. It is the journey that is the fun part. What else would you have been doing for the last 14ish years? "Nuthin' this good, that is all I am sayin' "

 

Yeah, it just takes what it takes, I kind of have to finish it.

The next project is the '47 Lincoln flathead V12 engine that I saw for sale and bought thinking the 308 was about finished....10 years ago? Back then I had a boat plan, today its a '26 roadster body based autoX car. I had it out last week to take some measurements and weights as I start plotting......because the 308 is going to be finished soon

 

Ive been wanting to ask you guys about this gasket , or sealer you have been talking about, and or using, Im having a problem with my 84 Kawaskis valve cover leaking , its going to a shop tomorrow that fixes older motorcycles, can you tell me what type of sealer your talking about that you guys are using to stop leaks ? Maybe I can suggest it to the mechanic, he has a system that he uses that works, I wanted to see what you guys suggest, or if Im climbing up the wrong tree. With that being said, Im always excited to see when you get this project successful !!

Thank you