Thread: Engine experts........need your help again !

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Thanks to all of you for such good info and questions. Thanks to Shine for his taking the time to PM me with his ideas also. As far as a good machine shop here locally, not really. I wish we did have someone who was of the level of some of you or ones that you can find in some big cities, but here in SW Florida it is hard to find those kinds of shops.

Here is what we have decided to try first of all. Today I spent most of the day on the phone with Mr. Gasket, Mondello, and Permatex. Every one of them was more than helpful, to the point that I had to apologize for taking up so much of their time. Here is what we are going to try first:

Mr. Gasket suggested their 404 gaskets for the sides and silicone sealant for the front and rear end seals. I picked up a set locally.

Permatex suggests NOT using the black rtv I have been using, but rather to use their Ultra Gray Sealant # 82194 on the intake port gaskets and to use their rubber sealant #85409 on top of the rubber end seals.........OR if we don't want to use the rubber end seals just use their product "The Right Stuff" which is made to use with no gaskets at all. In fact, he said we could omit ALL the gaskets and just use the Right Stuff on everything. He said it was developed for racers who need to assemble parts and then hit the track immediately, and it has super sealing properties on mismatched, ill fitting parts.

Mondello feels the Mr. Gasket set with the sealants suggested by Permatex is going to fix it. But if not he said we can FedEx the manifold to him and he can machine it to fit our heads........says he does it all the time and knows where it needs cleaned up, if I leave the marks on it for reference.

So, tonight we are going to use the gaskets, but no end seals. We are going to coat the heads, gaskets, and intake VERY well with the Ultra Gray, and use the Right Stuff to form the end seals. We will let it cure for 24 hours and then see what we have. If that fails, the intake will be pulled and sent to Mondello in California.

As far as the guides or seals or anything else causing some leakage, I don't think so. There is SO much oil dripping out of the intake ports and staining the gaskets in that lower area that it HAS to be coming in from there. Plus, we didn't have this problem in the very beginning. When we broke in the engine there was no smoke or plug fouling. It only started after the car was driven for some miles.

Again, guys, thank you very much for all the help. We are more fabricators than we are engine builders or mechanics, so it is very helpful to have experts like all of you to rely on for good advice.

I'll let you know what we get tomorrow night when we fire it up again.

Don

A little update. Last night Dan, Don, and I worked on Dans car and got the intake reinstalled. We used the Mr Gasket intake gaskets but did not use the rubber end seals. We used Permatex The Right Stuff and created our own end seals from that. We then used the Ultra Gray Sealant on the heads and on top of the side gaskets, then put an extra coating on the intake where it meets the gasket. Basically, we gooped the h*** out of it.

We let it cure 24 hours and tonight we fired it up. It smoked a little for a few seconds then stopped, probably because there was so much oil in the cylinders and headers. After a while it stopped and Dan took it around the block. Then he and I took our cars for a long ride to dinner and back and there was no smoke and Dan said the power was much better.

There was only a hint of smudging on the white insulators, and again I think that might be from the tons of oil in the heads and cylinders. That engine has to be coated inside from the amount that was sucking in. He is off this weekend and we plan on taking some very long drives both days to see what happens then. If nothing else the oil problem is 99% better, and as Jerry and some others suggested, the guides may be letting a little in. If that is the case he plans on just living with it until he recovers financially from building the car and then we can properly tear into it and fix it right.

The other thing is that the engine only has about 500 miles on it (maybe less) and the rings might not have fully seated yet. We took the compression test again and got about 195 across the board, with two cylinders at 190 and one at 200. So we will just wait and see.

Again guys, thanks for all the input and help.

Don

Well, it looks like our little repair didn't hold. Last night Dan and I took our cars for about a 100 mile ride and his car burned a quart of oil. We decided it is time to correct the problem once and for all, so today we removed his intake and both heads to see what is going on. Here is what we found:

1) Jerry and some of the others weres right about the valve guides. We removed the springs from a few of them and all of the bare valves wiggle slightly in their bores........the guides are worn. I think the radical cam he is running may have shortened their life, or they were not done properly to begin with.

2) The intake gaskets are still not holding a good seal. It seems the heads have been milled so that the intake is not dropping far enough into the valley to seal well. Don has a set of C heads he was saving and has graciously offered them to Dan to use. We are going to have them totally gone through, SS valves, new guides, postive seal valve seals, 3 angle valve job, etc. Then we will see how the bare intake lays on the heads and use Richards clay method to see if they match better than the heads now on the car.

3) We also found a real shocker. The second cylinder back on the passenger side is badly scored. It is right at the bottom of the cylinder wall, is about an inch wide, and pretty deep. It looks like some of the carbon that is all over the valves, from the over oiling situation, broke off and as the piston traveled up and down it scored the wall. We have a bunch of money in the block so Monday I am going to call the local machine shop and see if that cylinder can be sleeved. The engine is already bored 40 over, so we don't want to go any further. If need be, we will buy one new piston, if the one in there looks damaged when we get it out.

What do you guys think about bronze vs metal guides? His cam has a fair amount of lift, and I understand bronze holds up better under that circumstance. How about those positive seals that you have to machine the heads to use, any good?

This is not going to be fun because the body has to come off to get the engine out of this car, but we have already done that to fix the transmission a couple months ago. We are going to make sure every component is perfect this time before the engine goes back in, don't want to be doing this too often.

Don

Don

One other thing---what and how are the breathers on this engine???PVC? or just valve cover breathers/ road pipe(old,old school) or nothing???

And did this engine have umbreela type valve stem seals???

You can probably put a .060 piston in that hole instead of sleeving the cylinder.

Jerry, we had only a breather on the oil fill pipe at first, then we added a pcv valve on one valve cover with a K and N breather on the other side. We thought the pcv might be sucking some oil into the intake so we temporarily disconnected plugged it.........same results, so we hooked it back up.

The seals on the heads were soft rubber umbrella seals and we bought a new set of the hard nylon ones and replaced the intake ones on the front two cylinders, didn't make any difference.

We thought about the 60 over piston in that hole, but think the gouges might be too deep for a 20 cut to remove. It got scored pretty good, but the machine shop will know for sure when we take it there. Does putting a bigger piston in one hole upset the engine balance, or do you have things rebalanced after?

Don

The piston weight needs to be close to the same weight as the one you have and no rebalance would be necessary---

You said you could wiggle the valves in the guides---with umbrella seals that will let it suck a lot of oil and if the heads don't drain back good it will gobble up a lot---just don't want to follow a car like that as it will get your windshield oily!!!!

What do you think of the positive type seals that require machining to fit, Jerry? I looked at some in the Summit catalog, do you like one brand over another? What about the bronze guides vs steel?

Yep, when I was following Dan the other night I could smell oil burning when he accelerated or slowed down especiially.



Don

I like the teflon type(perfect circle) ---if you replace the guides, you will just need the size to fit the guide od---generally .502 guide---on heads that haven't had guide work, they are cut to .531 with a piloted cutter--simple operation-- for higher performance engines I prefer the bronze guides---can even be a liner fitted to the stock guide boss--these then have a spiral tool ran thru then=m which sweges the liner out and then it gets reamed/honed to size---the spiral then holds some oil in the grooves which help lubercate the stems

From what I've seen in your deal---the loose guides/umbrella seals with one bad piston/cylinder(excessive blow by) overwelmed the PVC/breather system and actually forced oil from the high pressure crankcase via the easiest route thru the 2 intake guides

A note for everyone about compression tests----they will always be hifh with oil in the cylinders sealing the rings---a better test is the cylinder leak down test---this one cylinder would of been 40 % or more

Good advice on the Perfect Circle seals, I had considered those too. I agree that the pcv system was not able to keep up with the blowby. The K & N breather on the drivers side valve cover would emit smoke at times, when it should have been the inlet for air into the engine. He also got some oil drops on the firewall after a long drive, from that breather.

The funny part was that we did a leakdown test on all the cylinders and all showed 10%, which I understand to be good. Maybe the large amounts of oil in the cylinders sealed them for that test too?

I'm actually looking forward to building this engine again, this time taking extra care in the fitting of all of the components and making sure everything is sealing well. The shame of the car is that everything else works so great on it.............it goes right down the road, handles well, rides great (it should, it weighs a lot more than most similar cars ) it shifts fine, no leaks anywhere, etc. But this engine thing is keeping him from enjoying it after such a long build. Time to correct that and get the car back on the road.

Don

i like the PC hi temp viton with the steel chimney i use them on every thing they are a 200.000 mile seal EZ . like jerry said if new guides with a 502 then its 500 body if a thin wall liner or stock then 530 body can be used a 530 cutter will be needed . i only use a solid guide for guide repair not thin wall speed linners they work ok but i am all set up for all the 502 iron or bronze and i stock 100s of them . i use alot of iron 502 guides they work fine for most stuff .mag bronze works very well but 2X the cost were some cry about the price .i have a mix of the iron guides in plane wall and spiral cut for oil hold out less wear on guilds that and snake skin valve stems remflow could be good for some free HP