Hotter front cylinder

[superjetguy]

Let's talk about my setup. I've got a 83mm 61x/62t stock carbs, r&d head ~200psi comp, b pipe, single cooling t'd into both manifold inlets exiting out two holes in the head one to pisser one to top of head pipe, bottom outlet on head pipe goes to the tip of the expansion chamber and t'd to a pisser. The front cylinder is running much more hot than the rear, almost to hot to keep my hand on it for more than a few seconds.. I have double checked my hoses and none are kinked or blocked, what should I do? Oh by the way the fcv isn't hooked up it is only being used to mend the hoses until I can get to the store.

 

[amitchell]

Open up your high speed screw a bit and cool it off? are your jets staggered?

 

[amitchell]

Does the FCV have the spring in it?

 

[superjetguy]

No the fcv is empty.

 

[superjetguy]

No my jets are not staggered.

 

[amitchell]

Well if the front goes right to a pisser than it should flow enough water to keep it as cool as the rear in theory.

Maybe do a leakdown, you could be pulling air in the front and leaning out.

I picked up an infrared thermometer ($20 on Amazon) to check temps, around 120F is good at the head.

 

[kevbo]

Are you talking water temp or combustion temp?

 

[amitchell]

Water. I am unable to check combustion temp. If you point the infrared at the head its going to be damn near the exit water temp.

 

[superjetguy]

Okay I have the new hose in and it looks way more clean but I'm not pissing much out of the top of the head pipe, do I have the fcv in the wrong spot?

 

[superjetguy]

The flow control valve is inline In front of the T to the pisser and stinger.

 

[amitchell]

FCV after T the pisser off the 90 on the T

 

[amitchell]

you don't want to stop flow below FCV pop off rpm at the pipe. Water should always be able to flow at pisser.

 

[superjetguy]

Okay. Will change thank you

 

[amitchell]

In the tech FAQ forum is a good B pipe cooling thread.

 

[iangdesign]

200 psi and a pretty much aftermarket engine set up and you are only running a single cooling line. I'd be afraid to run my ski at all. If all your hoses are blockage free there maybe a block or restriction somewhere in the cylinder.

Where is the hose on the head in the rear cylinder coming/going from/to?

The "T" past the FCV is that going overboard? If so move the FCV past it.

 

[Vumad]

Are you running race fuel? I believe 200 psi is too high for 93 octane.

 

[Vumad]

Let's talk about my setup. I've got a 83mm 61x/62t stock carbs, r&d head ~200psi comp, b pipe, single cooling t'd into both manifold inlets exiting out two holes in the head one to pisser one to top of head pipe, bottom outlet on head pipe goes to the tip of the expansion chamber and t'd to a pisser. The front cylinder is running much more hot than the rear, almost to hot to keep my hand on it for more than a few seconds.. I have double checked my hoses and none are kinked or blocked, what should I do? Oh by the way the fcv isn't hooked up it is only being used to mend the hoses until I can get to the store.

You have single cooling in but dual cooling out. This could be causing your head pipe to run hot which can cause everything to run hot.

You could try putting a wye on the 2 lines off the head and send the combined water to the pipe. So, 1 line in wye to manifold. 2 lines out of head wye to one line into pipe. 1 line out of pipe wye or tee with straight side of tee going to pisser and base of tee going to FCV to stinger.

Make sure your compression is appropriate for your application. Get a cheap $5 harbor freight thermometer and see how hot is hot. We had a blaster that ran great for a long time and still was when it sold, was 140 degrees on the head. You can't hold your hand on 140 but the motor lasted fine. I also second the leak down test and carb checking, but I would start with your pipe cooling first. If that doesn't work, try true dual cooling. Just like you have it except 2 lines in.

 

[Nemo]

You can use an inexpensive probe type food thermometer and check the temps coming out of the lines on the front and rear of the head. Use a control valve or pill on one water line to get the two outlets about even in temperature.

 

[Fro Diesel]

Haven't seen it mentioned yet so...

Be sure to restrict the water coming from the top of the headpipe. A plastic spacer works well at 3-4mm. Otherwise, the water will not be pressurized inside the headpipe. This is important.
If not, water will dribble instead of stray and js/sj will start talking about water migration, then blamo, you've wasted a whole hour reading pointless nonsense.