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So.... are saying that IF the engine had some valve "float" at my "drag race" 5,500 RPMs, the floating valve(s) would contact the top of the piston? Yes exactly.This interesting because I believe the 261C cam profile has one of the higher overlap (6.2 degrees) of the cams I have recorded or tested. QUESTION: Could excessive camshaft overlap (significantly greater than a stock cam profile) be more likely to cause valve float, and potentially cause valve to piston interference?Yes absolutely. Changing the lift, overlap, and duration will 100% increase the potential for valve to piston contact. This is controlled by stiffer valve springs, multiple valve springs, larger valve relief and a designed rpm range for a specific cam profile. Gnarls.
UPDATE: FEB 24 Sunday PMI got the head off.I see some things. I took some photos.The photos did NOT come out as well as I wanted. The vavle/chamber contact areas are shiny alloy looking, the photos don't show that reflection.#1 & #2 chamber - There is appears to be contact on the chamber where the exhaust valve opens and closes.There is appears to be contact on the piston by the exhaust valve on chamber #2.Chambers #3 & #4 color looks different, as they had normal compression.I cannot yet determine where the coolant leak is on chamber/cylinder #3The hone marks on the cylinder walls do not appear to be at 45 degrees?I need to do some editing and labeling then I'll post the photos.Since I am not a head expert, I will take this head into someone I trust can examine it, and hopefully tell me why it failed.I have a lot of questions.Gnarls.
Do a basic leak check on those valves using very light compressed air and brake clean/water (besgen trickle down). Remember, ur looking for compression loss...And what about head gasket? Main sealing rings? Is there a cylinder cleaner than the rest?
Im sorry besgen 86 4runner
Two things Valve floatAnd what fuel are you running (tons of carbon)Wait wait I got it... Arco fuel? Saving money again Gnarly?
Two things.... LOL.... 1st - contact.... what caused it? 2nd thing...yes... there is carbon!!! It was burning 1 quart of oil every 600 miles. And.... NO... I don't burn Arco. I burn whatever Fry's Market pumps or Costco.... 87 octane. Saving money, being frugal, is NOT a bad thing. If you are rebuilding a 22RE, buying less than quality parts to save money is not very savvy.... that's just my experience. Gnarls.
Dont use factory head, aluminum is very porous
Buddy, years ago, did a head gasket on his 4runner 22re to solve a coolant leak issue, had oem head sent out. He installed it and after very little time he was using coolant again. Now, im not sure if he had known cracks before in it, but he chopped it in half with band saw and it revealed alot of erossion from electrolysis and showed how porous the head was inside the cast...
My engnbldr head that I bought years ago was made in South America according to what he told me. I had a problem with casting voids in the head causing a liquid leak into the exhaust chamber. The only thing the 261 cam did for me was allow more torque at a lower rpm. I am going back to a stock cam with my new engine I will install this spring.
You should consider starting a thread just about cam shafts for 22r and 22re? Just an idea... It might be worthless....
Hey bgen! Well... IF my engine rebuild had come together like I was expecting it to, I would have had my truck on an engine dyno at least 3 times by now!! ... And I'm NOT kidding!I wanted to "test" by swapping camshafts in my freshly rebuilt 22RE.So... I don't know that I will get to do that? I have some more work to do on getting my truck in the restored condition I hoped to.On the cam thread... there's lots of information I posted already with lots of input from some guys like H8PVMNT. I'd have to find the thread. [EDIT] HERE'S A CAM THREAD: https://board.marlincrawler.com/index.php?topic=100575.0Of course.... it could all be worthless opinion. Gnarls.
Maybe the cam thread would be best described as moot pointless...
blackdiamond....You should stick to learning about the Fletcher Munson Curve..... More Lift and Duration is something you probably could use. Gnarls.
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