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I’m sure they will give you a break on the price

They do good work. I’ll send my head there
 

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Discussion Starter #122
I know what detonation is and I know what it sounds like. I also know that I dont want to hear it because the damage is already a possibility at that point.

My question is have you guys heard these kfx motors detonate?

I have 110 octane unleaded and I am going to break it in for 2 full tanks on that and begin to mix it downward. I am wondering if the sound is going to be prevalent when it happens, and will there be other signs?

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I know what detonation is and I know what it sounds like. I also know that I dont want to hear it because the damage is already a possibility at that point.

My question is have you guys heard these kfx motors detonate?

I have 110 octane unleaded and I am going to break it in for 2 full tanks on that and begin to mix it downward. I am wondering if the sound is going to be prevalent when it happens, and will there be other signs?

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Yes! Detonation pings loud, misses, causes very poor performance & aluminum flakes all over your spark plug... Pre-ignition usually follows punching a hole in the piston & sending the crankshaft out the front of the case...Thus grenade the motor...

What's your compression ratio & can you retard your advance ignition timing...??? example Procom or dynojet...
 

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Discussion Starter #124
Yeah absolutely...

Around 13.3 - 13.5:1

Pcv autotune
Accel
Full dasa
Fci intake
+3mm stroker
JE 12.8 forged 96mm piston.
Decked head
Stage 2 hot cams
Stage 2 porting
Brand new stock valves and springs with a 5 angle seat cut
I have a procom and I got it working good with the pcv but I'd rather use the stock ecu at first to keep the variables minimal.

I plan on keeping the timing retarded out of the gate and was hoping to keep it a bit rich but because of a ton of variables being thrown together I'm not sure how close the autotune will land on the first fire up.

Have suggestions for the first start?


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Looks great!

Keep in mind all of the procom maps have advanced timing which can raise the octane required slightly.

How does the porting look?
 

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Discussion Starter #127
Far as the naked eye goes the porting looked fine. I didnt see any deep gouging or crazy offsets but I'm sure it was cnc so it looks like it should. I'll never send anything to dasa again because of the lies they kept telling. Initially it was 3 to 4 days in shop turn around time. It took 8 weeks. I called once a week because every time I called they said yeah it's right here it's done and were are shipping it out today or tomorrow, but they never did. Like I said before I didnt even care about the time it took, I just dont like being lied to.
I cant wait to try it out though.
The kfx ran pretty good before but this should be pretty crazy!

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Discussion Starter #128
I didnt spend a bunch of time on this yet but heres what I have and I was hoping some direction would give me what I'm missing.

I put the engine together and I'm getting spark and fuel but it only fires, but wont start. It turns over well and I checked the compression and it's only 62 psi. I lost my leak down tester somehow. Looked for an hour so I'll order another one. Used shop air at 65psi and could hear air coming from both exhaust and intake. Not crazy amounts tho. I have the valves i take valves at like .10mm and the exhaust at .18 Seems like too much overlap if I crank by hand and watch closely. Theres almost no time where they are both closed... everything is brand new except the head ... it was sent to dasa and has brand new stock valves and springs.
Any thoughts?

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Intakes are too tight

Set them to .15mm

Exhaust is fine but still towards the bottom of the spec.
 

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Discussion Starter #130
Found my leak down tester.... I'm going to reshim first but how much pressure should be used on these engines to test?

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Discussion Starter #132
I've had about an hour to play with it but this is what I have so far.... like 50 psi on compression, cold with no throttle or oil added to cylinder and 62psi with wot.
I have good vision and with a close look with a bright light and cranking slow by a wrachet counter clockwise I find that valves set to: intake- .14mm and exhaust at .20mm... are opening in about 4 times each revolution....though the big lift is only with the top part of the lobe like it should and when it spins I can see it start to open both intake and exhaust just barely at about 4 o'clock, 6, and 8 o'clock. I dont think this is right, has anyone seen what I'm talking about?

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Discussion Starter #133
I had to make the compression release side of the exhaust cam .14mm in order to get 72 psi on the compression test. If not, when its cranking over it studders every time the compression release goes by. And wouldnt start that way... cold with wot

It seems I have more compression when the compression release is working.

I'm assuming the cam compression release button is worn... and second thoughts on that?
Considering the valves and springs and valve seats are new.

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I had to make the compression release side of the exhaust cam .14mm in order to get 72 psi on the compression test. If not, when its cranking over it studders every time the compression release goes by. And wouldnt start that way... cold with wot

It seems I have more compression when the compression release is working.

I'm assuming the cam compression release button is worn... and second thoughts on that?
Considering the valves and springs and valve seats are new.

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Your quote from above..(Found my leak down tester)....

What's your piston compression...?

Also with higher compression you'll need a stronger battery with more CCAs..(Cold cranking amps)...a weak battery with high compression will be sluggish & turn too slowly resulting with more air leaking past the compression release...preventing the motor to start...!!!

Service manual compression test is 49~81 psi...stock piston CR 12.0:1 normal is around 70 psi...13.0:1 is around 80 psi normal test range...13.5:1 is around 90 psi normal test range

I thought your doing a leak down test to find compression leakage...?

Leak down tester requires an air compressor at 100~120 psi for best results

leak down tester pictured...
 

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Discussion Starter #135
I have the leak down from the pic. Not %100 on how it works. If I screw the regulator in to increase the air flow the left gauge/pressure gauge is at 30 psi when the cylinder leakage gauge goes most of the way around and lands on 0% and it says "SET". If I continue to screw the regulator in to obtain a pressure higher than 30 on the pressure gauge, the cylinder leakage gauge continues to move past 0% and tacks its self to the back side of the pin that the needle was sitting on when it started. I screwed the regulator in until the pressure gauge said 100psi and the leakage gauge didn't budge off of the back of the pin it started from the opposite side of.

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Discussion Starter #137
I do hear a good bit of air moving out of the exhaust and intake.

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Discussion Starter #138
I also see where a small amount of coolant came out between the jug and base when I had around 100psi in it. Not a oem gasket but I have one and I'm putting it in now. The head gasket is OEM. Arp studs at 46ft.tq

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I also see where a small amount of coolant came out between the jug and base when I had around 100psi in it. Not a oem gasket but I have one and I'm putting it in now. The head gasket is OEM. Arp studs at 46ft.tq

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Have you had time to break in the motor & seat the piston rings...???

Is the piston @ Top-dead-center, (same as checking the valve clearance/re-shim)..?...and yes it best to use an air compressor rated at 100~120 psi, 2 gal or more to have enough air volume to prevent the compressor to turn on while testing...the rest you did properly

A new top end the leaking gauge should be in the upper green near the 0% ....!


Do you have a standard compression tester..if yes...what results do you get...??

Service manual compression test is 49~81 psi...
stock piston CR 12.0:1 normal is around 70 psi...
13.0:1 is around 80 psi normal test range...
13.5:1 is around 90 psi normal test range
 

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Discussion Starter #140
I have a 100 gal compressor and it didnt kick on. I dont understand why they would make the gauge not even make it on the scale... I mean it never even budged off of the pin once it pegged. I had it on for 30 sec at 100psi. So I'm guessing its holding compression.
I have a 2 normal compression gauges. One of them holds the pressure inside until the cranking is over and can be released afterwards and it only gives me about 30psi. But I have one that bounces every stroke and it gives me about 72psi wot cold. That's with the exhaust cam shimmed at .14mm. With it shimmed at .20mm it was about 60psi.
Keep in mind that the last time it ran I rode it one day and the next it wouldnt start. I had low compression and couldn't figure it out so I replaced everything new except the head and cams. I had it decked and a valve job with new oem valves and springs. Now I am still having issues with compression. I'm around 13.5:1 and shimmed properly I'm only around 60psi.


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