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your springs might be weak and with such a short duration cam at 5k weak springs would cause the valves to float like bestgen said.
I can see it's possible, but I've "floated" valves before in other engines. I have never detected valve float in any of the 22s I've owned. I ran the sand dunes in my 85 22R at least 3 times, my 86 longbed 22RE automatic at least 2 times, and I was at 5,000 and 5,500 RPMs all day, and sometimes hit 6,000 RPMs.... never once did the engine misfire or act like a valve floated. My 1985 was a stock rebuilt head with a Toyota stock 22R cam. I did cross-country Mexico through the giant sand dunes out to the beach, and ran it 5,000+ all the time.Gnarls.
Yes... supposedly all new. I don't know what valve spring pressure are, or whether they are referred to as HD or heavy duty?Gnarls.
Just an FYIThat's way to high of RPM for this engine. It makes no extra power up there. You are just reving the out of it.I don't think I have ever taken My currant engine past 4k rpm.Look at You desk top dyno. power drops off before that hi of RPM.
If your hitting the rev limiter your doing something wrong or your name is Dingman.
Your other 22r engine were stock? With stock cam and pistons?
I agree that the upgraded cam profile will change the efficiency of the stock springs, and valves will float earlier in the RPM range, this is a very soft aftermakret cam though. Oversized valves are heavier and will affect the rpm at which valves float too. My opinion is that the engine will usually stop revving when the valves float before the valves hit the pistons unless the clearance is very tight to begin with, or revved with no load. The 22re rev limiter is also quite low at around 5800rpms I believe? Engnbldr has built and sold thousands of heads like yours, it must be expected some people will buy these heads and run them for competition or mudding or whatever that will see sustained high revs and abuse. A margin of safety is built into them I am sure, if the machining is done correctly. If the engine ran well before the first high rpm pull, then ran like crap after that, it would be a logical cause, but I don't think that is the case. I believe it is a machining error(s). And while we are speculating, I'll even go on a limb and say that the block is fine and all the trouble is in the head. Get it off and send it out for inspection first.
Here's my off-the-wall thinking....According to the FSM, the valve length of the intake is: 4.468"The exhaust is: 4.480"That is .012" difference.Is it possible that the valves were switched without being noticed? Or... the valve stem length was wrong?Gnarls.
Hey G...I agree with everything you said, however, I'm skeptical that the difference in the weight of the 1mm stainless steel valves will cause them to float at 5500 RPM, even if the springs were stock.And I too think that I'm going to find something in the head/valves. My gut keeps telling me its the length of the valve stems and/or the valve seats.I will pull the head and get it into someone I trust can give me a quality inspection and diagnosis.QUESTION: Could the valves/guides, seals, seat have caused the 1 quart of oil burning in 600 miles. I had not blow-by, no smoke at cold or warm start. I have tach'd this engine up to 5,500 RPM at least a 12 times in 1st gear.Gnarls.
Are the valve seals on there? Some times complicated problems are the stupidest thing you can think of.
I thought valve stem seals were black thingies...….
...I'm skeptical that the difference in the weight of the 1mm stainless steel valves will cause them to float at 5500 RPM, even if the springs were stock.
I think you're making an assumption there. In my experience, assumptions are defined as things that prove to be false after costing you large amounts of time, money, and tears. Until you measure, calculate, or verify every one and find the one that was wrong.Sorry to hear your engine rebuild went west like this. With all this experience, the next one will probably take you a couple weeks and run like a top
Pull that head! Pull that head! Seriously, we all just speculating until you do some foot work. Im really curious! Hurry, its the weekend.
Yeah do it! Do it! Do it! Do it!
..... I am still thinking valves hit pistons with Your drag race rpms.
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