Those are good numbers for these little fella's! Mine are almost exactly the same, no kidding! Your good, keep on trucking!!!
So here's one for you, with good compression like this would you lean more towards bad valve seals being the reason for the smoking or still a good chance it's the oil rings?
Go back to the beginning of your question, on page 1! I think Donald Andrews nailed it with his great info that he provided all of us with! Valve seals, look to be in your future, my guess! Without pulling the motor. Keep us posted! Limestone
Absolutely, I probably couldn't get her done without Yas you will be kept posted. Thanks and again, stay safe
Have somebody follow you, while you drive it. Run up the rpm in second or third gear, and then drop the throttle. If you are pulling oil through the guides, they will see a puff of smoke while the vacuum is high. In reference to the compression test data of roughly 179-psi. That is actually pretty good. These engines have a theoretical compression ratio of about 10:1, and one atmosphere is roughly 14.7-psi at sea level. So if your engine was 100% volumetrically efficient, the 179-psi is a compression ratio of 12:1. Which is very good, and why I run high octane gas in mine.
Awesome, very informative and much appreciated. So high octane gas, is this something I should be doing also?
Back in my misspent youth I had to rebuild an engine that had been run on gas with too low of an octane rating. this resulted in pretty severe detonation, and the guy kept running it on the wrong octane, until he cooked the engine. All four piston, and the cylinder head looked liked someone had gone at them city a center punch and hammer, the faces were covered with a series of small pits. That was a minor effect of detonation. It can completely destroy the engine by blowing holes through pistons, bending rods, enlarging the position pin holes in teh pistons. If you don’t run an engine hard you can get away with the wrong octane level. but if you pushing it hard it will detonate, and the results can be catastrophic.
Ok I'm very glad you informed me of this. I'm fairly new to working on vehicles but I've been working on ATV's my hole life and have seen some nasty Pistons. Some exactly how you've explained. Never put low octane gas as being the culvert! Always assumed that running em hard and bad air filters were the main reasons! Jigs-n-fixtures your knowledge is awesome. I love learning new stuff, especially when it involves new love(kei trucks) wow how great it would be to have you next to me, passing down your knowledge but this will work! Thank you
When you say you run high octane gas, is it still just higher octane gas at the pump or do you go beyond that and buy an even higher octane gas than 91 octane. I believe 91 is the highest we can get at the pump in Nova Scotia. It may even only be 90
I think what I’m running is 91-octane. I’m at 4000-ft altitude so the engine needs less octane, regular here is only 85-octane.
Jigs, I'm curious! In your so called misspent youth, ALL KIDDING ASIDE, did the severe detonation, make noise, like I'm assuming, where you could tell something was wrong, or am I off track here? I guess what my point is here, as I've all ways had a hard time, watching, or seeing things, get tore up for no apparent reason! Kinda fries my #@%$!!! To be honest! Watching these guys on the racing circuit, take note; weather it's pro or amateur, MAINTENANCE!!! To me that also includes Fuel Octane! So when I hear from more than one person, on the mini truck forum, to use high octane fuel, it sure gets my attention! As I've stated on more than one occasion, I believe in Sta bill, as a fuel addative, or other ethanol enhancer's, or booster's so to speak. Maybe the answer here is a higher octane fuel to help elliminate problems with these finicky mini carburators! Limestone
When the engine is in the mild detonation cycle, it sound like some body put a bunch of 1/4-inch ball bearing in the cylinder. I purposely make my Chevy work truck detonate. Some bean counter decided that we have to run the lowest octane level fuel available at the pump, irrespective of what the manufacturer says the vehicle needs. The manual says 92-octane. The lowest octane at the pumps here is 85. So if you head up a hill, and slam the throttle it sounds like somebody is pouring gravel in the intake. Really pisses me off, because Shell actually did a study, and ran half of their fleet, on the lowest at the pump, and the other half at what the manufacturer recommended. The cost per mile was less on the ones running the recommended octane. Modern engines, have higher compression, and very good advanced engine management systems, to optimize fuel economy. If you run them on a lower octane fuel, the management system retards the timing, and enriches the mixture in an attempt to prevent detonation. So, you get worse fuel economy, and increased engine wear.
Jigs, I really don't like to hear an ENGINE knock at all ! I like you was taught it's not good for the motor, at all. I just don't see how it could be! Even the big diesel's need to warm up before you pound on them, working them hard! I appreciate your input! Limestone
I don't quite understand how to do the math on this one. Still learning! If I'm at just around 80 meters above sea level, should I be using lower octane than 91
This is all making sense to me now. I've been running lower octane in my truck(99 carry efi) even with it being efi, when I hit any good size hill, weather I had to gear down or not, my motor sounded very upset! It had me stressing quit bad, I heard the pinging noise and no matter how hard I tried to push it aside, it consumed me all day. Last night I was just about on a quarter of a tank, I filled er with 91 octane, took her to the highway and held her to the floor. Not to mention I just put new ngk plugs in er. The pinging was completely gone. I didn't hear it at all! Very impressed and quite pleased with your knowledge jigs, you my friend are the man. Thank you!
One thing that I do know is, you can never go wrong with a higher octane fuel! It won't hurt your truck, just your wallet! So for me, see what yours likes and go with it!!!
One of the ways to determine what you need, is to start with the higher octane, and then do third gear, full throttle, acceleration runs, from idle up through the rpm. If it isn’t knocking, next fill up don’t fill up, just put in a quarter or half tank of the next lower octane. Keep doing the acceleration runs, With progressively lower octane fuel, until your start to gain time on the acceleration runs, and then go back up to the last one which was working. Shel, the lower your elevation the more octane you need to prevent knocking. The method above, will help you figure out what your truck needs. Your at sea level, so it will be fairly high.
That's awesome, greatly appreciated. I've been running lowest octane until yesterday, I was at half a tank of gas on low octane than filled the other half with highest octane and ran it all day yesterday and today and I noticed an improvement in motor sound so today the same thing, I put more highest octane and noticed and improvement in sound and performance. I'm guessing rite now I'm in between medium octane and highest so I'll run er to E than do your 3rd gear test first with high octane than medium octane. This may take a day or 2 but you will know which works best for me. Thanks a lot guys!
I will say this, sense I've been messing around with higher octane fuel, I've noticed a huge difference in my truck preforms. With low octane, for months I've had a strange idle pattern. The idle would go up and down. I couldn't figure it out, I messed with the MAF sensor, air filter, I've used seafoam, I couldn't get it to idle steady, I thought it must have been a weak injector but sense using higher octane, my idle is near perfect, excellent
91 octane is for me! Excellent so maybe you guys can help me with, or give an opinion to this. I really enjoy my truck, it is my daily driver, that and my versa. But I'd love to up the hp a bit and I see someone near me has a super charger for small engines. In the post it says ideal for 1.0's, kei trucks, side by sides etc! It doesn't come with an intercooler but says no need if your keeping the boost 7psi or lower. Is this something worth doing a lil more research on or are these engines to delicate to amp up a bit?
A supercharger will definitely up the horsepower and torque. The question is, can you do the work required to install it? If it wasn’t a stock option, you’re going to have to figure out how to mount it, and possibly weld up a new intake manifold, or an adapter. If it was a stock option you will need to source and buy all the bits needed to make it work. Not trying to be a jerk, but the guys with the skill set to do the install, probably wouldn’t have asked the question.
This is totally new to me, hence- all the questions lol. I take no offense at all my friend, your opinion is very valued. I'm a cert welder so I do have that part down lol, the rest is black magic to me hah. I'm already in the mist of making a header and putting a 2 inch exhaust on er, maybe I'll slow down until I figure more of this supercharger possible option out. kinda knew most of what's needed to install a supercharger, except if the engine will handle that kinda strain. F6a engines were paired up with a low boost turbo factory but I've only seen the sambar engines which are 4 cylinder with a supercharger. I know the two , turbo-supercharger are based on the same things, more air, I guess I need to figure out if there's any difference between the engines they factory turbod and my f6a engine. I asked that question on a whim, I just seen it and asked. I may go pick it up today lol and decide what to do with it lol I do know, the only year I seen factory turbos in the trucks are a 94 and my year, 99
I just watched a post by spaner on mounting a supercharger on a, I believe, 95. He was great enough to give detail pics of all the mounting plates he fabbed, basically everything he needed so pretty stoked, I'm on my way to pick it up here shortly, what info with it after I buy......... Who knows, but I'll have it
Warning on on the oversized exhaust pipe. It might cause a huge loss of torque. There is a ram effect which helps evacuate the cylinders. There is a very close relationship to valve diameter and lift. Some quick math based on a naturally aspirated engine. Our engines are displacing 660-ccs. So every revolution you move about 330-ccs through the engine, at 5000-rpm, you moving 1,650,000-cc/min, or about 58-cfm, of cold air, now you need to expand that for the difference in volume, for the air being heated. To do that, multiply it by 1.5. So, you have 87-cfm. Exhaust pipes move about 115-cfm per square inch. So our trucks need about 0.75-square inches of pipe. Or about 5/8-inch diameter. For an engine with boost, things go up. On turbocharged engines the size of the exhaust pipe isn’t very critical, because you want the minimum back pressure on the turbo, to let is spool up. So, as big as you can put under the vehicle is better. On an engine with a supercharger your still worried about exhaust pipe size. Even though it is less critical with the boost, you still need some scavenge to get max power. So, on them you want about to calculate for 2.2 cfm, per horsepower. So our little engines, with lots of boost, might get to 80-horsepower, and need 172-cfm, or 1-1/4 to 1-3/8-inch pipe.
I love that you posted this to me, I was really going by what someone else on here did to his truck, I've only started the header so far, I've got 1/3 inch plate fitted and planned on buying the rest of the material yesterday but something came up. 1/3 inch plate is what I had so it's what I used. Running no boost, what would you suggest for header pipe?
I'm out looking at my truck rite now. It's a 99 efi Carry, I measured my exhaust, my cat is located in the rear of truck and the exhaust that goes into and out of my cat is 1 1/2 inch. From what I get from what your saying is that my exhaust isn't factory? Would my truck have come with inch and a half exhaust? I always thought, to a certain degree, the bigger the better. Is that not the case with a factory carry
I'm so confused, when you say 5/8 inch pipe is all we need for factory carry, am I measuring my pipe the way you are. I measure from side to side, is that what you mean when you say 5/8 inch in diameter or are you measuring more scientific lol excuse the pun, I mean no disrespect, I truly appreciate your input. This is all very new to me, I'm a ATV mechanic, this is all very new to me and I do love it but I want to be sure I understand properly before I start making big mistakes.
Inside diameter! That still sounds tiny to me. 5/8 inside diameter, that would be roughly 3/4 inch pipe. 5/8 sounds right for my exhaust manifold, I took it off last weekend to fit my header plate and the manifold exhaust ports were tiny, I assumed making them bigger by a fair bit, alone, would give me more performance. Am I way off, what jigs said sounds more like a 2 stroke, expansion chamber gives back pressure= more hp. I'm gonna stop now, I'm at novice level! Maybe I need more research. Lol thanks guys
