Hmmm?

[domn8tr]

So i noticed oil around the 3rd plug hole on the head on the L20b in my 521 so my son and i pulled the head and sure enough found some "milkshake", also 2 helicoils in cyl's 2 &3. In my spares i have a peanut head that has been race ported to about 1.4 in intakes and the guy i got it from said the valves were triple ancle cut. The head appears to be shaved some but the towers are not shimmed. he also said it was align bored. I have several Cams and was thinking of using a U20 i have thats clean. I also have a stock peanut head that is complete and looks to have plenty of meat. I'd like to use the race head with the Pace setter single side draft manifold with a 45 weber and a valve cover I also have with a spraybar. Mike (SDSurf) said the block had been decked 15 though and i noticed the flattop pistons are 4th over. Would I be able to use the race head as is or do I need to shim the towers to keep the geometry correct. Are taller lash pads needed ? I'm also concerned with chain slack. Id prefer not to use the stock peanut but if need be I will rather than the stock messed up U67. Wadda ya think?

[datzenmike]

So i noticed oil around the 3rd plug hole on the head on the L20b in my 521 so my son and i pulled the head and sure enough found some "milkshake", also 2 helicoils in cyl's 2 &3. In my spares i have a peanut head that has been race ported to about 1.4 in intakes and the guy i got it from said the valves were triple ancle cut. The head appears to be shaved some but the towers are not shimmed. he also said it was align bored. I have several Cams and was thinking of using a U20 i have thats clean. I also have a stock peanut head that is complete and looks to have plenty of meat. I'd like to use the race head with the Pace setter single side draft manifold with a 45 weber and a valve cover I also have with a spraybar. Mike (SDSurf) said the block had been decked 15 though and i noticed the flattop pistons are 4th over. Would I be able to use the race head as is or do I need to shim the towers to keep the geometry correct. Are taller lash pads needed ? I'm also concerned with chain slack. Id prefer not to use the stock peanut but if need be I will rather than the stock messed up U67. Wadda ya think?

 

By milkshake, you mean there was oil and water in the cylinder??? and the helicoils are in the block between cylinders #2 and #3???

 

If they were helicoiled then something must have damaged the block. If this was not done properly perhaps they are loose or damaged again causing the head to loose it's clamping force.... perhaps the head is warped. The vertical oil gallery that feeds up into the head is between #2 and #3 so a warp or loss of clamp might cause the oil to seep out sideways.

 

This is an L gasket looking up from under the head. You can see at the top outer edge there is a copper lined oval hole for the oil gallery.

 

 

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[domn8tr]

I apologize I meant to say the 2&3 sparkplug holes are helicoiled buy yes the milkshake was around the oil galley. also it appears the engine sat for a while with water going into the #2 cylinder as the wall had etching from the coolant passage on down. I just Mic'ed the U67 that was on the engine and got 4.15 in . the race ported peanut came in at 4.25in. i guess thats why the towers were shimmed on the u67 head. Can i use the rockers off the u67 head as the A87 has no rockers. do I need to swap rockers and cam as a set or can i swap rockers and use the cleaner u20 cam I have in my spares.

[datzenmike]

Shaving won't affect valve lash, wipe pattern or any valve geometry but it will add some chain slack. Shimming the cam towers lifts the cam up away from the rockers and might. See Hainz's vid on this to get a good answer.

 

You can use the rockers from the U-67 head on the cleaner L20B cam. However they will have a very very slight 'wear' pattern on them for the cam they are mated too now. In non racing engines I would inspect them and if smooth just install and run with them. Others will have them 'reconditioned' by using something like 1500 wet sand paper on a small sheet of glass and lap them.

[domn8tr]

Thanks Mike thats the answer I was hoping for. Looks like I'll be swapping stuff over today

[datzenmike]

If you can see any pitting then I wouldn't use one. The wear pattern should just look like a shiny patch on the rocker. This can be dressed with very fine paper so the cam can 'wear' in it's own new pattern. There's no sense having the rocker wear pattern grinding against the cam too.

 

Again I've swapped rockers before and nothing happens. The stock cam and rocker surfaces are extremely hard and durable if receiving adequate oil. An after market cam is a total unknown and I would be much more careful with it.

 

You should do some research on ZDDP content in the oil you are using. This is a zinc antii scuff additive added to oil to protect cam surfaces but newer cars are designed differently and less and less is being used in the latest oils because it is ending up in the environment and affects the new catalytic converters. Our old motors have been by passed by technology and emission regulations and may not be getting the proper protection needed. Diesel motor oil still contains fairly high levels but it is extremely detergent. Using diesel oil in an old motor can strip carbon from the pistons and rings that are an integral part of sealing in the compression.

[domn8tr]

Head Installed! Rocker surfaces had no visible wear as did cam since I don't believe SDsurf had ran it much since the rebuild. I've decided to use a 32/36 for mileage concerns as well as a dogleg 5 speed. I need to look through my spares and see if I have a roadster diff that will give me a higher ratio. Ideally I would like to cruise the freeway at 75mph below 3000rpm. BTW Bob3 my son has that Pacesetter manifold your looking for hit him up Akara1@gmail.com

[DanielC]

Valvoline VR-1 racing motor oil has the ZDDP in it the camshaft needs.