gunk on rear valves

[rivolution]

Hi friends

 

I took my intake manifold off yesterday, and noticed some gunk built up on the back/top of some of the intake valves -- on both sides, but ONLY in the four rearmost cylinders.

Here's an image with a look down each of the intake ports on the passenger side (sorry, I wish it was sharper).  The drivers side is the same, with build-up on only the rear two.

 

any thoughts on causes?  or solutions?

thanks,

Jeff

 

[rivolution]

sorry -- I forgot to mention, 1964 with 425

 

 

[1965rivgs]

Jeff,

  That is a classic symptom of oil getting past the valve guides. Could be valve seals if someone upgraded your engine with them, worn guides or oil pooling at the rear of the head. Make sure oil is draining from the head back to the crankcase. If you`re not getting any BLUE smoke during operation or at startup dont sweat it...you could start running a fuel additive to slowly clean the backs of the valves or if you`re particular the heads should get some attention,

Tom Mooney

[telriv]

BEFORE I did ANYTHING else I would try a BG product called 44K. I've been using it for MANY years (35+) & it actually does what it says.

[1965rivgs]

  Considering that you already have physical access to the back of the intake valves you might want to consider a more direct solution...I am a little hesitant to suggest it though because a hard pice of carbon trapped between a valve and the seat could lead to bad consequences. However, with a little common sense and a product that truly dissolves the carbon buildup you should be OK.

  If you progressively loosen the rocker arm shaft hold down bolts on each bank you should be able to seat/close all the valves. At that point you can use a carbon disolving product to clean up the back of the valve heads without the product running into the cylinders. I would allow the product to soak with physical agitation if possible and use compressed air, an air pistol and a rag over the intake port to control the washback of solvent to clear/clean solvent and debris from the intake runner. Make sure to progressively tighten the rocker shaft bolts when reassembling being sure all the pushrods are properly seated. After doing so, rotate the engine a full 360 degrees by hand to be sure all is properly in place.

  Tom mentioned BG products which I have no experience with but when I checked their website they also offer this product:

https://www.bgprod.com/catalog/gasoline-fuel-system/aerosol-carbon-eliminator/#bg-product-4

  I have used this 3M product to clean the sort of carbon buildup you are confronted with on fuel injection throttle body assemblies and can say it works extremely well:

https://www.3m.com/3M/en_US/company-us/all-3m-products/~/3M-Throttle-Plate-and-Carb-Cleaner/?N=5002385+3293193959&rt=rud

Good luck!

Tom Mooney

 

 

[telriv]

I didn't mention that the 44K is put into the fuel tank. I usually did it with a full tank of fuel & directed the customer to fill the tank again at 3/4 full. Then again at 1/2 tank. Then once again at 1/4 tank. Makes the product last longer & lessens the chance of removing too much at one time. AND  it will NOT remove so much that it breaks up into pieces. It dissolves carbon a little at a time so there are no ill effects.

Couldn't be easier, just add it to the tank.  IF you think it's nec. you could after you gone through the 1st. step add another & the deposits will be gone.  Also helps to clean the carbon off the pistons & exhaust valves at the same time.

IF you check the BG website they have MANY products for our cars.  AND I swear by them. Some may think the products are a little costly, BUT better than having to take things apart & then running into other problems.

Like it's said fix it till it's broke is a common saying.

Just my dimes worth by someone that has been using their products for over 35+ years.  The advertising is NO BS.

 

Tom T.

[jframe]

11 hours ago, telriv said:

BEFORE I did ANYTHING else I would try a BG product called 44K. I've been using it for MANY years (35+) & it actually does what it says.

I would second ANY BG product. Sold it for years and it is truly exceptional. Only available in car dealerships.

[60FlatTop]

Now is a good time to do a cylinder leakdown test with some soap bubbles around the valves. If there is not a lot of sludge blocking the oil returns the valve guides could be warn. The guides can wear enough so the valves don't seat in the same concentric area every time and it can get worse. You can also take the rocker arm assembly off and see how much wiggle you can make with your finger at the top of the stem. If it is bad you will notice.

 

How many miles on the engine?

Bernie

[rivolution]

Thanks very much for your help, all of you.

 

I'm actually planning on removing the heads anyway, because the freeze plug at the rear of the right head is leaking coolant, and there is some signs of oil leaking down the block from the head gaskets.  I've got a pair of new BEST head gaskets which won't leak oil (I'm told).

The engine isn't old or tired -- it was professionally rebuilt about 15 years ago and has less than 3K miles since then.  I don't know why this one freeze plug is corroded, all the others look fine. They are steel, though, instead of brass.  I had it built by a shop in Fresno because Ed Mosler was there, one of the few people around who knew how to port nailheads.  But the builder was not a nailhead specialist, so some of the build doesn't follow what we'd consider the best practices (hardened valve seats, for example).

 

Even though I've had this riv for 20 years, this will be the deepest dive I've taken into my engine, so any advice is welcome.   I've drained the coolant from the radiator, got the accessories off...  Any pitfalls I should watch out for?   What do you all favor for lubing the head bolts during re-assembly?

 

 

[telriv]

Drain the coolant from the block also by removing a 7/16ths. brass fitting plug on each side of the block.  Prevents coolant from entering the cylinders when removing the heads. ALSO there's less clean-up from the coolant spilling all over the ground.

ALSO on the head gaskets leaking oil out the rear of the block. What I do is I block the rear oil hole from the rocker arms.  This hole dead heads at the block as the heads could be put on either left or right. I know that oil can leak between the layers of head gaskets.

IF you look at the oiling holes there's one front, to oil the rocker arms, & one rear.  IF you stick something in there you will see it's about 2" deep.  Take a #7 drill & drill down about 1 1/2 " & then run a 1/4" tap down there.  Get a 1/4" set screw with an Allen head & tighten it into position. You don't have to worry about it coming out as the head bolt will keep from going down & the rocker shaft bolt will keep it from coming up.  Permanently STOPS the oil leaking from the rear.  The rear hole serves NO purpose other than be able to swap heads left-right.

The head bolts really don't need to be lubed, BUT you could put a light coating of some type of lube on them to help prevent any galling or pulling of threads.  AND DON'T use a wire wheel to clean the threads or the bolt holes in the block.  It rounds the threads & the bolt has a loose fit. ONLY use clean out taps & dyes as they DON'T remove any metal as a regular tap & die set does as the clean out taps & dyes are a few thousandths smaller/larger so no material is removed.  Make sure you pay attention to the length of the head bolts. Depending IF A/C or not the front right has longer bolts.  All the bolts are threaded into blind holes except for the three below the valve cover which require a sealant of some sort. I use Permatex 300 for this purpose.  IF you end up using a long bolt where it is NOT REQUIRED you stand a good possibility of now cracking the block.

IF the head gaskets that were used to assemble the engine were the Felpros then you won't lose too much compression using the Best gaskets. IF the shim steel gaskets were used then the Best gaskets will drop your compression more than 3/4ths. of a point.  IF off the shelf cast pistons were used then your compression is about 8-1 IF your lucky, maybe less.

Contrary to beliefs Brass freeze plugs only good thing is they won't rust. Brass is softer & doesn't seal as tight as steel & DO have a tendency to pop out. I DON'T USE THEM. The steel plugs lasted more than 50 years why do you think you need Brass???  They should have been replaced when the engine was rebuilt.

Closely inspect the hardened seats for ANY signs of leakage or coming out of place

Just my observations.

 

Tom T.

[RivNut]

Deja vu. Today when I opened my tablet, as usual it opens to some information that it thinks might be of interest to me.  I recently Googled BG Products K44.  Well, Google came through for me.  It found a month old article comparing fuel injection cleaners.  Lucas was #1 but this particular Lucas was for diesel engines.  BG K44 was #2 but was #1 for gasoline engines.  I searched the websites for the local jobbers and found nothing. But you can get it through Amazon.

Ed

[rivolution]

Thanks for the detailed info, Tom.  This is exactly the stuff I needed to know

 

 

[jframe]

7 hours ago, RivNut said:

Deja vu. Today when I opened my tablet, as usual it opens to some information that it thinks might be of interest to me.  I recently Googled BG Products K44.  Well, Google came through for me.  It found a month old article comparing fuel injection cleaners.  Lucas was #1 but this particular Lucas was for diesel engines.  BG K44 was #2 but was #1 for gasoline engines.  I searched the websites for the local jobbers and found nothing. But you can get it through Amazon.

Ed

Many car dealerships carry it as well.

[rivolution]

One more thing Tom (or anyone),

Is it possible to remove the head with the AC compressor still connected?  I've been pushing it around and  resting it here and there while working.  It's not ideal, but the system isn't empty, and at this point I'd have to bolt a lot of stuff back on to drive it someplace and have it discharged.  Am I in for a world of disappointment?

 

also, regarding the freeze plug -- I was thinking of putting a brass one in only because this one steel one appears to have corroded in a small area enough to leak.  All other freeze plugs appear in mint condition.  I'm all for putting another steel one in, but I'm puzzled at why this one at the back of the head didn't hold up.

 

[rivolution]

to clarify --  the AC compressor is detached from its bracket, but not removed from the engine bay -- it's still connected to hoses, etc

 

[telriv]

Just use a small diameter nylon rope to hold it out of the way & tie it to something. Remove a fender bolt & get a longer one with a good sized washer on it to hold the compressor out of the way.

[telriv]

When the offending plug is removed look it over closely & I think you'll find the problem. MAYBE nicked, pressed in wrong, something else????