higher compression requires better head sealing

[Steve Best]

I have blown teflon headgaskets but it was really a head failure, not a teflon failure.
The heads give and warp, easy to verify afterward. Has not happened with a thick head.
I do have to try it on the Blaster. High pressures and temps will tell the tale.

 

[Aladdin91]

Sorry i was in major need of help my nabior put windex in my gas tank but luckly could catch it before it got bad i got it running good again i was useing 8 oz to 1 gallon after 2 tanks switched 4 oz for 1 gallon it was running fine untill tge issue so i went back to 8 oz 1 gallon and tomarrow im lowering radio

 

[KCvale]

I just can't help it... To the Noobies here with few tools...

Who posting here actually uses a torque wrench in the proper sequence when attaching the head?

How many of you don't even know what a torque wrench is or how to use it?

A torque wrench is a tool used to apply precisely a specific torque to a fastener such as a nut or bolt. It is usually in the form of a socket wrench with special internal mechanisms.

A torque wrench is used where the tightness of screws and bolts is crucial. It allows the operator to measure the torque applied to the fastener so it can be matched to the specifications for a particular application.

Seriously!
How many of you are just 'guessing the torque by feel' and then wondering whats wrong?
Well DUH, this is critical thing at the point of combustion and requires a precision tool to do the job right!

You can talk about different gasket material until the cows come home but it don't mean s**t if you don't torque the head on properly with the right tool to measure it.

I run my 4 head nuts on a 66 down 5# at a time in a X pattern until all are 20# and I simply don't get head issues regardless of the gasket material.

That is 16 individual readings.

Heck, places like autozone loan torque wrenches, and even an OK one is better than guessing.
Under $30 all over like here.
https://www.amazon.com/gp/product/B...6d-0ab5-53c3-9063-fe500e13a356&pf_rd_i=559968

Just consider it a 'smart' socket wrench as you can change the socket size to what you need to torque.

Again, get all 4 to 5# in a X pattern, then to 10# in an X, then 15#, and finally to all 4 at 20#.
I usually swap my head orientation, usually with paint, and they all go back on the same gasket with no issues using that procedure.

I truly hope that helps you noobs as it really it is important.

 

[gary55]

I torque to 162 in. lbs. I have a good feel for the sequencing so I don't have to keep changing the wrench. Torque specs. on the studs are 168 in. lbs..

 

[Steve Best]

I torque mine too KC, but I am pushing the engine beyond stock, with higher compression pressures and better cylinder filling.
I totally agree with you. A lot of the problems we hear of, stripped studs, broken cases, are from over torque.

 

[Aladdin91]

I

Hello Aladdin,
You are kind of hijacking a thread here, but you are new and need help.
Your head did not look like it blew a headgasket. It looks like you have lots of oil.
Your piston has clean "wash" areas on top that indicate too much fuel.
One quick way to "lean it out" is to move the clip on the needle in the carb throttle slide.
If you move the clip to the top position it will lean out the carb mixture.

Frankenstein was also alluding to checking the carb float level.
I would suggest you may have too much oil in your fuel too.
Are you running between 24:1 to 32:1?

am running 16.1 and it runs good just bogging at full throttle whats a good fix

 

[Steve Best]

I'd suggest you can go to less oil, try 24:1 and see if you can feel any improvement.

The full throttle bogging is typically a main jet issue. Does it run better in cold weather?
If so, the main jet could be too rich (too big too much fuel).
Typical main jets are a #70, so try running a 68 or 65 and see if there is an improvement.
Look up and read up on "plug chop" plug reading, to see if your jetting is right.
Too small a jet and you will seize a piston, ruining piston and cylinder.

In the interim, you can lower your float level slightly to see if this has any effect.
If it improves full throttle performance it is worth buying some jets.
Lowering the float level messes up some other things, so don't look at it as a permanent solution.

 

[KCvale]

I torque to 162 in. lbs. I have a good feel for the sequencing so I don't have to keep changing the wrench. Torque specs. on the studs are 168 in. lbs..

162"# is only 13.5'#, I like them tighter, 20'# or 240"#.
The trick is to NOT take each one down down the whole 20# at once, ease each one down 5# at a time to get a great fit.

Again, this is for a 66 Skyhawk, for a 48cc stop at 15#, and for some of those $50 66cc engines I'd stop at 15# with them too, but all I use are real Skyhawks and they like 20# just fine ;-}

 

[gary55]

Sometimes I question why I even address this kind of nonsense. Both of your numbers are well over torque specs.. In the case of the 15# on 6mm stud it is excessive by 200%. No body is using 8.8 on 8mm or 12.9 on 6mm. for head studs, not even the illustrious skyhawks.

 

[Aladdin91]

I'd suggest you can go to less oil, try 24:1 and see if you can feel any improvement.

The full throttle bogging is typically a main jet issue. Does it run better in cold weather?
If so, the main jet could be too rich (too big too much fuel).
Typical main jets are a #70, so try running a 68 or 65 and see if there is an improvement.
Look up and read up on "plug chop" plug reading, to see if your jetting is right.
Too small a jet and you will seize a piston, ruining piston and cylinder.

In the interim, you can lower your float level slightly to see if this has any effect.
If it improves full throttle performance it is worth buying some jets.
Lowering the float level messes up some other things, so don't look at it as a permanent solution.

I orderd a carb should come next week i raised the c clip on notch so its on 2nd to top will that work