rjenman Posted October 1, 2005 Report Share Posted October 1, 2005 I asked here and on other forums whether my 4K-C needs leaded, and I was told yes it needs lead substitute. However I was reading the "how to build a tough K engine" thing in the wiki... and it says "Valve seats made after February 1972 are made of hardened steel and are fine for use with unleaded petrol. Toyota Corporate themselves told me this." and my car is a 1981... so.... I should stop bothering with lead substitute? :hug: Link to comment Share on other sites More sharing options...
Tiger Posted October 2, 2005 Report Share Posted October 2, 2005 I run mine on unleaded and I've had no drama at all with it. Link to comment Share on other sites More sharing options...
irokin Posted October 2, 2005 Report Share Posted October 2, 2005 Its been covered 4,000,000,000,000 times. Lots of guys run PULP and straight ULP no problems. I run Ultimate and Optimax but I havent decided which one I like more yet...they present very noticable differences to me in my celica. Ive killed one motor (2T) because we suspect combustion temperatures were too high for the rings (rings failed while just cruising on the highway). This current motor Ive been running some valve saver stuff to try and bring the combustion temperature down. It tends to knock a bit less when I run the valve stuff too even though I run 98RON in a 8.5:1 N/A hemi headed motor...go figure Link to comment Share on other sites More sharing options...
dingo ke55 5k Posted October 2, 2005 Report Share Posted October 2, 2005 Ive been running my 4k and 5k using unleaded with no problems. Remember though if you have a hotty best to use premium with the higher octane, but with petrol prices at the moment :hug: best stick with regular, ether way it wont hurt them. Link to comment Share on other sites More sharing options...
Dan Posted October 2, 2005 Report Share Posted October 2, 2005 I run mine on unleaded with a teeny bit of two-stroke mixed in... Link to comment Share on other sites More sharing options...
kangaroosa Posted October 2, 2005 Report Share Posted October 2, 2005 Just touching on the additives side of this topic since the original question has been answered. Has anyone mixed Castor Oil in with their fuel? My old man told me people did this when he was young. There is no performance difference apart from maybe lubricating something. The reason for mixing in the oil was that it kinda makes your exhaust smell like a blend of race fuel. I tried this on my 4K and had few people ask me what fuel i was running..........they call you a few names when you tell them its just unleaded. I didnt notice any side effects apart from $7/Litre. But when you only have to mix in 200ml or so, then its OK for a show off factor now and then. Link to comment Share on other sites More sharing options...
Dan Posted October 2, 2005 Report Share Posted October 2, 2005 I put 2-stroke in for lubrication... something my old man told me to do... plus it boosts the octane level marginally... Might try the castor oil thing, the officials will wonder what the hell is going on!!! Link to comment Share on other sites More sharing options...
Felix Posted October 2, 2005 Report Share Posted October 2, 2005 i've never had any hassles running with ULP or PULP. you won't have problems unless you run to lean, or don't adjust your valve clearances on a regular basis. LOL. pilots in WW1 had the shits all the time from the castor oil in their fuel. Link to comment Share on other sites More sharing options...
Super Jamie Posted October 3, 2005 Report Share Posted October 3, 2005 "Valve seats made after February 1972 are made of hardened steel and are fine for use with unleaded petrol. Toyota Corporate themselves told me this." and my car is a 1981... so.... I should stop bothering with lead substitute? is 1981 later than 1972? yes, it is so you don't need the additive stuff :D Link to comment Share on other sites More sharing options...
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