Predator 212 wont fully start

[BrownStainRacing]

Ah, gotcha. I’m very familiar with catch cans. Had an IAG on my WRX before I sold it

Head gasket is +.010. I still have the vent tube coming from the valve cover. Since I took the vm22 from the old engine and put it on the new one, I took the new OEM air filter, cut a little piece out, and stuck that in the end of the valve breather. Did the same with the gas tank breather too. I will def buy a 1 way valve on eBay. Thank you!
At this point, I feel like you’re my small engine consultant! Minus the pay. Feels more like Lt Dans new legs actually.

You will need 2 of those check valves, jus 1 still leaves alot of pressure in the crankcase.

When you get those check valves pull the valve cover off and pull that whole plate, that's holding the baffle in, out. Drill another hole in the valve cover, between the rockers, so you can add a nipple to connect to the 2nd check valve.

With the +.020" rod and a .010" thick head gasket, you created a catastrophe jus waiting to happen.

That +.020" rod moved the piston up to top of deck, now you have .004"- 0" piston to deck height. The .010" makes this .014" -.010", this is not enough. These cranks, rods, side covers will flex at higher rpm. That piston will hit the bottom of the head, and that's not gonna be a good day. The magic, safe number we are looking for here is .030". Put in a .027" head gasket with copper gasket spray and you will be fine. Put harden flat washers between the top of the head and the head bolts, only 1 for each head bolt. this makes a better seal on the shim head gaskets.

The last time I had a piston hit the head was with 0 deck height with a .018" gasket. About 6500 rpm. It smashed the bottom of the billet rod, broke the cam gear off the cam, and broke the side cover. When I tore it apart there was only a small nick in the piston and the head. It only took 1 time for the piston to kiss the bottom of the head.

Do you have the stock non hemi dished piston or the stock hemi flat top piston?????

 

[LtDansNewLegs]

Yikes! I do not want armageddon in my engine. I will definitely order that head gasket, and thank you for defining it with a specific spec part!

Double yikes with just a small peck of a kiss and that ***** nearly took your life!

Yup, I’m currently running the OEM non hemi
predator piston in my engine. Do I need an aftermarket one?

 

[BrownStainRacing]

Yikes! I do not want armageddon in my engine. I will definitely order that head gasket, and thank you for defining it with a specific spec part!

Double yikes with just a small peck of a kiss and that ***** nearly took your life!

Yup, I’m currently running the OEM non hemi
predator piston in my engine. Do I need an aftermarket one?

The flat top from the hemi is a drop in piston for the non hemi. It will bump up the compression ratio and make that cam a little more happy. You will see a big difference in that cam when you get the CR up.
I've turned that cam 7800 rpm in a 12.8:1 CR 196cc on 108 octane fuel, 26lb valve springs, stock rockers and pushrods. It was a freaking demon.

Use this CR calculator to play with.

Compression Ratio Calculator

The compression ratio calculator finds both the static and the dynamic compression ratio of your combustion engine.

www.omnicalculator.com

 

[LtDansNewLegs]

You will need 2 of those check valves, jus 1 still leaves alot of pressure in the crankcase.

When you get those check valves pull the valve cover off and pull that whole plate, that's holding the baffle in, out. Drill another hole in the valve cover, between the rockers, so you can add a nipple to connect to the 2nd check valve.

With the +.020" rod and a .010" thick head gasket, you created a catastrophe jus waiting to happen.

That +.020" rod moved the piston up to top of deck, now you have .004"- 0" piston to deck height. The .010" makes this .014" -.010", this is not enough. These cranks, rods, side covers will flex at higher rpm. That piston will hit the bottom of the head, and that's not gonna be a good day. The magic, safe number we are looking for here is .030". Put in a .027" head gasket with copper gasket spray and you will be fine. Put harden flat washers between the top of the head and the head bolts, only 1 for each head bolt. this makes a better seal on the shim head gaskets.

The last time I had a piston hit the head was with 0 deck height with a .018" gasket. About 6500 rpm. It smashed the bottom of the billet rod, broke the cam gear off the cam, and broke the side cover. When I tore it apart there was only a small nick in the piston and the head. It only took 1 time for the piston to kiss the bottom of the head.

Do you have the stock non hemi dished piston or the stock hemi flat top piston?????

If I get a new flat top/hemi piston, will that change how thick of a head gasket I’d need? If so, do you know how thick I should go?

 

[BrownStainRacing]

No, you will be fine. That +.020" rod moves the piston up closer to deck, bringing up CR. Now with the flat top, it's not going any higher, but will bring your CR up even more. You will be fine with a .027" head gasket. Get the 70mm, not the 68mm.

Seems like there was something else I was gonna mention, but I'm lost again

 

[BrownStainRacing]

If I get a new flat top/hemi piston, will that change how thick of a head gasket I’d need? If so, do you know how thick I should go?

I remember now.

That pred non hemi head has a 20-21cc combustion chamber. With the flat top piston, and .027" gasket that should put you around 10:1 CR. That's still ail low for that cam.

Now some 196cc clones have a 18cc head. Keep your eyes out for a junk one, or a cheap running 1. Using the 18cc head will put you at 11:1 CR, then that cam will wake up and run for you. With around 28-30 degrees of ignition timing, you will still be able to run 87-89 octane fuel, whatever is available in your area. We got 87 here.

 

[LtDansNewLegs]

I remember now.

That pred non hemi head has a 20-21cc combustion chamber. With the flat top piston, and .027" gasket that should put you around 10:1 CR. That's still ail low for that cam.

Now some 196cc clones have a 18cc head. Keep your eyes out for a junk one, or a cheap running 1. Using the 18cc head will put you at 11:1 CR, then that cam will wake up and run for you. With around 28-30 degrees of ignition timing, you will still be able to run 87-89 octane fuel, whatever is available in your area. We got 87 here.

Thanks again for your detailed analysis! Do you prefer ARC or NR over the other or same ****, different brand?

The research I’ve done said the stock timing is 28 degrees. I bought a 4 degree offset key for my PVL Flwheel since the manufacturer recommends starting at 28-31 degrees. I haven’t done this yet, but PVL also recommends “that you leave only 1 of the blower housing recoil air intakes open”. I’m not sure what that’s all about… The only two clearances I unfortunately don’t understand yet, despite watching multiple YouTube videos, is degree timing and measuring compression ratio.

I run 93 on my engine, on the off chance it may get .0001 more HP

With the higher compression ratio, you think I’m still good running stock rods and rocker arms? I bored my head as well

 

[BrownStainRacing]

I perfer pvl flywheels.
The crankshaft is what determines the timing. If using a pvl it should be 28. If using a ARC it should be 32. But the thing of it is, the keyway in the crank is always wrong. On non hemis, they usally check 20-21, so with pvl that will be 24-25.

To check your timing the CORRECT way is with the head off, you need a degree wheel, pointer, and magnetic dial indicator.

In your case, and I have checked a bunch of non hemi cranks, I would order a +2 key, since you have a +4 already. 28 is always best to start at, then slowly creep up 2 at a time, I never go passed 30, usally don't need to.

Pvl say that about the blower, cas it cools the engine down faster then most other flywheels. DO NOT TAPE UP YOUR BLOWER, UNLESS YOU HAVE A TEMP GAUGE.
I run a temp gauge, it's a tuning tool for me, I can tell if timing is too low, if engine runs hot. You have to have a temp gauge to learn this.

93 octane is safer for high compression engines, I dont build em passed 10.5:1 anymore, and use cams that close the intake valve earlier then most cams.

Stock rockers, pushrods and retainers are good up to 26# springs.

What do you mean "bored head"??

 

[LtDansNewLegs]

Nice! I don’t have a temp gauge and don’t plan on getting one so I’ll ignore covering up any vents.

I have 22lb springs since that’s what the .265 dynocam I have recommended.

In regards to boring the head, I went in the intake port with a Dremel grinding stone bit and took off a small amount on every surface I could reach. From there, I used a sander bit and then finished it off with a polishing bit. The smoother the intake ports are, the faster and more air she can take it. On the exhaust side, I used a grinding stone again and then touched up the walls with a sander bit. I did not polish the exhaust side. For whatever reason, exhaust fumes travel faster through a rough surface vs air moving quicker through a smooth surface.

 

[BaconBitRacing]

Nice! I don’t have a temp gauge and don’t plan on getting one so I’ll ignore covering up any vents.

I have 22lb springs since that’s what the .265 dynocam I have recommended.

In regards to boring the head, I went in the intake port with a Dremel grinding stone bit and took off a small amount on every surface I could reach. From there, I used a sander bit and then finished it off with a polishing bit. The smoother the intake ports are, the faster and more air she can take it. On the exhaust side, I used a grinding stone again and then touched up the walls with a sander bit. I did not polish the exhaust side. For whatever reason, exhaust fumes travel faster through a rough surface vs air moving quicker through a smooth surface.

I think that's backwards. Everything I have ever heard (from pro car engine builders) is intake rough, exhaust smooth. That way the rough intake keeps mixing your air/fuel and the exhaust flows quickly.

 

[BrownStainRacing]

You messed up.

The intake runner is too big to begin with. You rough up the intake so fuel will atomize, bust up, swirl while traveling to the bowl area. Opening it up is not good. Cold air and fuel moves slower then hot exhaust gases.

These heads jus need, clean up the flawed casting flashes in runners, and round off the sharp edges in the bowl area. I like to work around the valve guide, making it tear dropped shape pointing towards the runner, and knock those steep ramps down. Air and fuel travel best in a straight line, it don't like 90 degree turns.

Exhaust dont need much work at all. When the exhaust valve is open the piston is pushing the exhaust out.

There's plenty of pics online what a intake runner should look like.

With the bigger intake runner, it slows the intake charge down, looses acceleration, really only good for WOT racing only, like drag racing.

 

[BrownStainRacing]

@LtDansNewLegs
Hold off on ordering that flat top piston. Go look for a 14cc Honda clone head. They came on 168 clones. You might find it cheap and not have to get the flat top.

 

[LtDansNewLegs]

You’re right, I did it the way you explained now that I’m looking back at it. I have the head off now. Before I took the engine off my kart, I checked the spark plug to see if I’m running lean or rich, and it definitely looked rich. But now that I have the head off, it looks like it’s running lean? I’m basing that logic off the whiteish coloring on the exhaust valve. Thoughts?

Also, do you see the offset circle at the top of the head? Is that normal? It looks like the piston is way off center and is far too north in that picture. And on the piston side, it looks like the round wear on the piston is way too low!

 

[BrownStainRacing]

Looks OK. Might be because quench area too tight, .010" head gasket. Are you running any kinda addictive in the fuel??? There something odd about the coloring on the piston. Pull plu and get a good close up of the porcelain down in the plug.
E3 plugs are hot. I like cold plugs on modified engines.

I also need a pic of that intake runner.

I brb in about 20 mins.

 

[LtDansNewLegs]

Phew, that’s reassuring. I add Sta-bil storage to the gas. I’m def changing the head gasket to .027 like you recommended, so that should help.
I don’t plan on taking the exhaust, intake, or springs off since I’m fairly confident theirs no issue there. Unless you really think there could be a problem with the intake that made the engine top out at 38, then I’ll take off the carb inlet or valves. It took me several hours to put those 22lb springs in with just my fingers, so I’m trying to avoid messing with them. I felt like the grandma from Happy Girlmore…

Attached is a close-up of the spark plug. Outside of breaking in the engine, I only took it out once this past weekend for about 30 minutes, but I was driving like a bat out of hell, if that helps diagnosis your interest in the piston coloring.

 

[BrownStainRacing]

Phew, that’s reassuring. I add Sta-bil storage to the gas. I’m def changing the head gasket to .027 like you recommended, so that should help.
I don’t plan on taking the exhaust, intake, or springs off since I’m fairly confident theirs no issue there. Unless you really think there could be a problem with the intake that made the engine top out at 38, then I’ll take off the carb inlet or valves. It took me several hours to put those 22lb springs in with just my fingers, so I’m trying to avoid messing with them. I felt like the grandma from Happy Girlmore…

Attached is a close-up of the spark plug. Outside of breaking in the engine, I only took it out once this past weekend for about 30 minutes, but I was driving like a bat out of hell, if that helps diagnosis your interest in the piston coloring.

I knew you was running some kinda addictive, that weird color told on ya.

Put that sta bil in something else, use seafoam to keep the carbon from sticking, I use it in everything, sometimes even in my coffee,
Yea, you fat rich. Leave it for now. We'll get you some cold plugs and get some testing done and read new plugs when you get 'er back together.

Dont you hate those dam keepers, they rough on some fingers,

Those valves have to have those style keepers cas the valves stems are only 5mm. All the other factory heads have 5.5mm valve stems and use the stock retainers.

Those are good heads, with a lil port work, jus because they have those small valve stems. More area in the bowl with smaller valve stems, but they are a pita. Wait til you try a 26# spring,

As I was saying earlier, with a 14cc head, you would not have to change to a flat top piston to get more CR. It don't hurt to chk on the prices anyway, you never know til you look.

My sons ducar 212 has a 14cc head on it with that same dyno super stock cam. I'm not a fan of it, but it does start pulling hard when it gets up in rpm.

Lmk before you start ordering stuff. We get together and make sure you don't forget something.

 

[LtDansNewLegs]

Will do! OMB Warehouse is where I’m ordering from so I’ll check for that piston- I know they have the gasket. Go power sports takes FOREVER to ship and they never pick up their damn phone. They lost me after I place my first big order.
Thanks Brown Stain!
PS Having Crohns, I think I hold the title for most Brown Stains

 

[BrownStainRacing]

Will do! OMB Warehouse is where I’m ordering from so I’ll check for that piston- I know they have the gasket. Go power sports takes FOREVER to ship and they never pick up their damn phone. They lost me after I place my first big order.
Thanks Brown Stain!
PS Having Crohns, I think I hold the title for most Brown Stains

GPS done pi$$ed me off for the last time.

while you looking at omb, check on that 14cc head.

 

[ezcome-ezgo]

Magic legs.

 

[LtDansNewLegs]

Welp, after only taking the engine out once, the stock push rods are already bent a little… I’m no expert, but am a bit surprised they’re bent after only reaching a 38MPH top speed.
Do you guys recommend a specific length for chromoly push rods on a stage 3 212?