Hello, Mike here from Charnal House Racing.
We run the MetSHO in 24hrs of lemons; a geo metro with a mid mounted SHO drivetrain.
I was prepping our original 3.0L engine to go back into the car this weekend. I used this engine for 4-5 races until it started burning oil excessively. Since compression was good and I noticed oil on one exhaust valve, I figured it was valve stem seals. I bought some new stem seals from felpro and set about installing them when i noticed something weird. The new intake valve stem seals were clicking into place just fine, but the new exhaust stem seals did not have any press fit onto the valve guide.
This is because the top of the valve guide has sunk down into the head! The lip that normally catches the seal is below the surface!
On cylinder 1 and 2, 3 out of 4 exhaust valve guides had moved. Here is a picture
"Good" valve guide. On this guide, the stem seal installed normally and clicked into place.
"Displaced" valve guide:
Displaced guide from the top. Notice how there is nothing for the stem seal to grab onto:
Anyone seen this before? This motor ran great when pulled except for burning a little oil as mentioned above. We did overheat it badly once (260f) and it spent most races running at 220F coolant temps.
We run the MetSHO in 24hrs of lemons; a geo metro with a mid mounted SHO drivetrain.
I was prepping our original 3.0L engine to go back into the car this weekend. I used this engine for 4-5 races until it started burning oil excessively. Since compression was good and I noticed oil on one exhaust valve, I figured it was valve stem seals. I bought some new stem seals from felpro and set about installing them when i noticed something weird. The new intake valve stem seals were clicking into place just fine, but the new exhaust stem seals did not have any press fit onto the valve guide.
This is because the top of the valve guide has sunk down into the head! The lip that normally catches the seal is below the surface!
On cylinder 1 and 2, 3 out of 4 exhaust valve guides had moved. Here is a picture
"Good" valve guide. On this guide, the stem seal installed normally and clicked into place.
"Displaced" valve guide:
Displaced guide from the top. Notice how there is nothing for the stem seal to grab onto:
Anyone seen this before? This motor ran great when pulled except for burning a little oil as mentioned above. We did overheat it badly once (260f) and it spent most races running at 220F coolant temps.
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