Just Fishing's 09 Tahoe Build thread

Disclaimer: Links on this page pointing to Amazon, eBay and other sites may include affiliate code. If you click them and make a purchase, we may earn a small commission.

OP
OP
Just Fishing

Just Fishing

Can't fix stupid
Joined
Aug 30, 2020
Posts
3,936
Reaction score
8,552
Location
Utah
welp, i just cc'd my heads.
64cc confirmed!


once my new oil pump gets here, i'll be ready to button the bottom end up.
then it's confirm pushrod height is good, and verify valve clearance.

From there i'm clear to toss the bottom end in the tahoe!
then decide what i'm going to do with the heads.

According to the calculator i have, it says i'm @ 11.36 static compression ratio :eek:
 
OP
OP
Just Fishing

Just Fishing

Can't fix stupid
Joined
Aug 30, 2020
Posts
3,936
Reaction score
8,552
Location
Utah
getting ready to test clearances and confirm lifter preload.
Found my old 5.3 head gasket is exactly .030 when i removed the top and bottom layers.
And it's a 4in bore.

Fantastic for my next plan, to increase the chamber size to bring down that static compression.

(the separated head gasket is laying on top of the head)

upload_2021-5-29_9-43-2.png


So the plan is to drink lots of energy drinks, and to polish the chambers and remove some material.
then using my cylinder head cc kit, confirm balance and try and get a target chamber size of at least 67cc.

Found its easiest to use a little plastic syringe to fill the chamber until the glass shows full.
then use another plastic syringe with some shrink tube on the end (to allow it in the little hole) to suck up the fluid.
then put the fluid into the beaker to see how many cc's it took.

doing this last night, it seemed pretty painless to do it that way. :D
 
OP
OP
Just Fishing

Just Fishing

Can't fix stupid
Joined
Aug 30, 2020
Posts
3,936
Reaction score
8,552
Location
Utah
spent a bunch of time today on a cylinder head.
Cleaned up the chamber pretty well and got it shiny thinking i'm probably up to 67cc.
measured and it came out to 65cc... :rolleyes:


so out came the serious porting tools.
spent a bunch of time last night watching "head flow clinic" on youtube.
Has a whole series on the 799 heads
apparently these things have some material to work with.
but there are thin spots to watch out for.

One thing he was big on, "flowing the valves" on the side of the chambers.
where you pretty much open the sides up and create a slight roll to help flow in and out.
looking in the head, there is a big thick wall there, and it goes down!

so digging into the side, your just working with a bunch of material.


so what i did was to roll the sides.
Used the old head gasket that's exactly 4" bore as a guide
I opened the sides up to that gasket and did some rolling, and some deepening of the chamber.
working to not touch the quench area or to change the general shape of the chamber.

as i worked i used the untouched chamber next to it as a guide as to not change much of the design.
then once i had a good chamber i ran with that.

this is still somewhat rough, i need to do more cleanup and balance the combustion chambers so they all match up.
but so far this is about 68cc.

upload_2021-5-29_20-58-1.png


I think by the time i'm done, it will be real close to 69cc.

I'm also tempted to "raise the roof" of the exhaust port.
there was a few videos that covered that.
:jester:
 
OP
OP
Just Fishing

Just Fishing

Can't fix stupid
Joined
Aug 30, 2020
Posts
3,936
Reaction score
8,552
Location
Utah
Few of my favorite tools for porting and polishing.
3M cross buffs!
I found an ebay seller that has an awesome assortment of them
He has sizes from Giant 2", down to 1/2in.
(Summit sells just the 3/4in from what i have found so far)
Box has an assortment of all sizes and grits.
(the red ones make things very shiny!)

upload_2021-5-29_22-30-6.png


Then sandpaper rolls, i get these from Summit

upload_2021-5-29_22-32-28.png

Also in the picture, my long shaft cross buff tool
I love this thing, it's super beefy!

then a small assortment of aluminum shredding bits.
Easy to control as long as you keep everything lubed up.


and the die grinder is an old Lowes Kobalt special.
My first entry into air tools, from a little kit I got for Christmas years ago.

Super old and very abused.
I'm surprised it still works, but i did have to fix it once.
parts started breaking off inside and it clogged it self up. :D

Remove broken parts, and I was back in business!
 
Last edited:
OP
OP
Just Fishing

Just Fishing

Can't fix stupid
Joined
Aug 30, 2020
Posts
3,936
Reaction score
8,552
Location
Utah
Here is something i did yesterday.
my ears were ringing from the die grinder screaming in my ear.

got the idea from a little air dremel tool i have.
uses some plastic tubing as a muffler.

so i made this out of gorilla tape and masking tape after i decided i needed it longer.

upload_2021-5-31_14-13-5.png

works great, makes the tool super quiet, and i no longer have the exhaust blowing stuff off of the table.
 
OP
OP
Just Fishing

Just Fishing

Can't fix stupid
Joined
Aug 30, 2020
Posts
3,936
Reaction score
8,552
Location
Utah
Looks good.


This is some pretty scary stuff.
Originally i thought a little bit out of a corner or something would do it.


Assuming the head doesn't fail, it should flow better through the valves.
While doing this I'm focused on not changing the overall design, and then imagining how flow works when the fuel air gets squished by the quench...


overall, I'm sure I'm doing it all wrong.
:derp:



Just like that one time i took the "easy" way out and thought "hey, I'll just copy a factory gm config!!"
And then i was all like "oh fk, my compression ratio is how high?"
Then i was like "dynamic compression is nearly 10?!"
Then it was like "GM used how thick of a headgasket??! Oh Hell no!!!"


good times.
:jester:





:okay2:
 

Forum statistics

Threads
132,376
Posts
1,866,996
Members
97,011
Latest member
ihadtheories

Latest posts

Top