DO IT YOURSELF VIDEO'S.. How to cut a high compression,squish band, hemi head!

[joeak47]

I thought it would be fun to make some videos that show you how easy it is to cut a squish band hemi head.

I feel that anybody with some mechanical abilities could do this at school,or quite possibly at home. I believe that once you see it in video form,it becomes clearer how its accomplished.

A properly cut and designed squish band head will give big power gains across the entire rpm range with an easy bolt on part. I'm amazed how many people don't do this.

I tried embeding the video's but I'm doing something wrong. Hopefully the links will work. If somebody can tell me how to embed the video's,please let me know.
So here we go...

If you folks have any questions,please let me know. I know the lighting was crappy in some of the video's,but I was getting tired,and it was HOT!

If I missed anything,let me know that too, I'll correct it.

 

[blasterBruce]

Great vid there joe ! , Glad to see more people showing others how its done !

Edit ,
Wow Well just watched all 7 vids back to back , Needless to say I subscribed to your channel haha , Like I posted on your #7 Video You KOR, Best, SCD are The reason I'm learning as much as I am here , Glad to have people take there time to show others how stuff is Done !!

 

[joeak47]

Who knows how to embed video's? All I can seem to do are links.:-/


I FIXED IT! YEEHAAAAA!

 

[Quadrider10]

very cool! !

 

[sicivicdude]

It looks good man.

The trick to the 50% area rule is that's a normal starting point. If you're tuning for a higher rpm, you end up with a larger diameter combustion chamber (smaller squish area). If you're tuning for a lower rpm you generally end up with a small combustion chamber (larger squish area). The head you did the first time was tuned for a higher rpm range than it sounds like your engine is actually running at or the narrow squish would have started giving you trouble.

I "X and Y" my radius', I need to get off my lazy butt and make one of those fancy radius tools too!

I do my heads exactly opposite in order to make sure that I can always cut off more to correct any mistakes I make without having to go back and correct the next thing that I've already got right for the correction. I cut the combustion chamber first, take the "break" off of the edge, cut the squish area, and then cut the mating surface. That way as I work "out" each step is already going to have to be corrected for the next step anyway and I'm not having to backpedal if I "slip up".

 

[Quadrider10]

It looks good man.

The trick to the 50% area rule is that's a normal starting point. If you're tuning for a higher rpm, you end up with a larger diameter combustion chamber (smaller squish area). If you're tuning for a lower rpm you generally end up with a small combustion chamber (larger squish area). The head you did the first time was tuned for a higher rpm range than it sounds like your engine is actually running at or the narrow squish would have started giving you trouble.

I "X and Y" my radius', I need to get off my lazy butt and make one of those fancy radius tools too!

I do my heads exactly opposite in order to make sure that I can always cut off more to correct any mistakes I make without having to go back and correct the next thing that I've already got right for the correction. I cut the combustion chamber first, take the "break" off of the edge, cut the squish area, and then cut the mating surface. That way as I work "out" each step is already going to have to be corrected for the next step anyway and I'm not having to backpedal if I "slip up".

head hurts now....

 

[reagor]

currently i run premium pump gas premix in my blaster, if i run one of these heads do i need to increase my octane for the higher compression? what about timing? obvi this will require a jetting adjustment as most things do

i also must confess i did not watch all the videos yet i dont have speakers at work so i can only watch

how did you mount it in the lathe? im assuming your using something threaded in the spark plug hole?

 

[Quadrider10]

currently i run premium pump gas premix in my blaster, if i run one of these heads do i need to increase my octane for the higher compression? what about timing? obvi this will require a jetting adjustment as most things do

i also must confess i did not watch all the videos yet i dont have speakers at work so i can only watch

how did you mount it in the lathe? im assuming your using something threaded in the spark plug hole?

yes u will need a highrt octane gas. with how this head is, im guessing 93 or race gas. and jetting will need to be adressed too.

if ur running stock head, u shouldent be running premimum. i dident at least. now im running 93, cause of the head mod i had to do

 

[89blaster89]

i run premium also and i have a stock head, it runs better with the premium.

 

[sicivicdude]

Reagor, the stock head design is FARRRRRRR from ideal. You could basically run like 83 octane gasoline in it (if there were such a thing). The stock head can be redesigned to burn better, produce more torque, and more hp even only using 87 octane fuel (ask zmaro!). The trick is if you're willing to use fresh 93 octane gasoline, the head can be MUCH improved over the stock design.

A word of warning about this video and trying something like this (or getting someone you know with a lathe to cut one) unless you spend the time to guess, mod, test, check, and change you NEED to have the head properly designed. As I've warned in other threads, just a few thousandths too tight and you can induce detonation which WILL eventually lead to an engine failure (hole in the top of the piston or ring lands disintegrated).

This is not a "one size fits all" sort of thing. Head redesign needs to be tailored to a particular engine. The quite general "rule of thumb" of 165 psi and .050"-.055" squish area being a safe limit takes into account nearly all situations that a head on practically any cylinder or pipe or carburetor can run on 93 octane and STILL be ok. That's not to say that there aren't other situations where deviations from that "rule of thumb" aren't possible and workable but stray too far and you begin to seriously take your engine's life into your own hands.

 

[89blaster89]

this makes me want to get an aggressive trail port

 

[joeak47]

I'll be finishing that head up in a bit. I didn't get to it right after my first cup of coffee.

I'll get here polished up,CC'ed,and bolted back on for a test.

 

[89blaster89]

I'll be finishing that head up in a bit. I didn't get to it right after my first cup of coffee.

I'll get here polished up,CC'ed,and bolted back on for a test.

looking forward to it!!! now if only i had a lathe

 

[joeak47]

this makes me want to get an aggressive trail port

YES IT DOES!

I'm not exagerating when I say that you will be more than double your power output!

This head work and the "Aggresive Trail" ported cylinder works awesome with the stock carb! It phenominal compared to a piped and jetted stock blaster,which are fast in the first place.

Everybody calls it an "Aggresive Trail" port including me.
Hmmmmmm.... From here on out I'm going to change the name of mine.
I live in the desert...I think I'll call it

JoeAK47's "Aggresive Desert" port job!!!

I'll be starting my "Aggresive Desert" porting video's soon

I've got to personalize my porting in some way.

 

[blasterBruce]

I'm already subscribed to your channel , I like how simple you worded the videos as well , watched them all back to back last night twice haha

 

[joeak47]

I just added a few more video's to this segment.

 

[joeak47]

Ok folks...

I just finished head #2 and it cc's at 16cc's. Thats 6 cc's less than my first head.

The weird part is that the compression reading is still 130 lbs. I think the larger chamber on head #1 (22 cc's and 40% squish band) is the same volume as head #2 (16cc's an 55% squish band).

I was stunned to say the least.

Compression readings were EXACT!

The test ride went great! NO DETONATION!

This new head pulled just as hard as head #1,but it doesn't have the step cut. Amazing! What a phenominal head. It doesn't even have a tight squish band clearance (yet).

However.....THERE IS MORE POWER TO BE EXTRACTED FROM THIS HEAD!
I'm going to close up the squish band on this one too,using the "step cut" to get the same squish clearance ans head #1
Lets see what happens...

I'll do this tomorrow.

I'll be starting on head #3 soon. Head #3 will have a smaller combustion chamber.

 

[wwholden]

Subscribing.... I've been looking for a how to on this for a while. Im taking machining classes at a local college and this would be a great project. Can you post up any pictures of the tool you used to mount the head to the lathe? I know its prolly simple but just want to make sure Im not forgetting anything. Also I notice you make cuts then measure. Looks like you estimate and try to make smaller cuts till you get close to your final dimension. Why dont you just use the micrometers on the lathe itself?

 

[joeak47]

Subscribing.... I've been looking for a how to on this for a while. Im taking machining classes at a local college and this would be a great project. Can you post up any pictures of the tool you used to mount the head to the lathe? I know its prolly simple but just want to make sure Im not forgetting anything. Also I notice you make cuts then measure. Looks like you estimate and try to make smaller cuts till you get close to your final dimension. Why dont you just use the micrometers on the lathe itself?

The arbor is made from a piece of 1" diameter cold rolled steel that is about 6" long. It use to be a "lock pin" for a dock plate used to unload trucks. It is cut to replicate a "spark plug",and I make sure that the threads go all the way down to the bottom of the threads in the head.

The reason I don't use the "Tic" marks on the lathe wheels is because I'm machining a non perfect "cast aluminum" part that is wobbling until I can cut it "true". you will be amazed how non-concentric a blaster head is after it mounted to the arbor. There is NOTHING perfect about it. I also want to make small changes as I go,and I like to check my work. I try to match the outer squish band diameter to the head gasket that will be used on the engine,and they tend to vary in diameter a bit from one manufaturer to another. You'll see what I'm talking about when you start cutting your first head. You won't be paying any attention to the "tic marks on the dials". All "lead screws" on a lathe with the exception of a "ball lead screw" (the best kind and most expensive) will always have slop that has to be taken up before setting your measurement. The easy way around this is to use a DRO,but I haven't picked one up yet because they are expensive. A dial caliper is inexpensive and doesn't lie......ever. Dro's are the way to go!

Here is a picture of the arbor. I have lots of pictures of head work in my "albums". Check them out... Click away.

 

[wwholden]

Wow I just checked out your albums. You have shared a lot of great info.

Three questions:
1.) I saw in you photos you cut into the sealing surface of the head to get the head gasket to sit flush with the squish band. I didn't see you do that in your videos. Were you not happy with the results of sitting the gasket inside of the head?

2.)And in your videos you cut from the sealing flange into the head. While sivic says he cuts from the dome out. So that you can correct your mistakes without screwing up ones that are fine. Do you think you will change your process?

3.)In my machining classes I've taken we have not cut any spherical domes like that yet. Didn't even know it was possible. Can you shed some light on how thats done since that wasn't covered in the videos?