Engine builders ..... How do you ......??

[Jerryl]

How does one determine the alignment of the intake ports between the manifold and the heads?
Even if the ports on the intake and heads are matched perfectly to the gasket, there could still be an issue with alignment of the ports. The picture/drawing is really bad, but you get the idea of my question.

Not asking how much to mill off the surfaces, just wondering what you think is the best way to verify alignment.

PS
Looks like milling the intake sealing surface is going to be “fun” since you can’t really easily clamp it. Any ideas?

 

[Hacksaw]

This is a good question. Not every setup will allow exact, repeated alignment of a port.

Precision fasteners help. Notice how some manifold makers using 12 point bolts instead of 6 poing ones? It's also why you see 6 point bolts with shoulders under the heads in some locations.

But my gut feeling is that engine builders will open up the area on the part receiving whatever the flow is (A/F, oil, etc.). So, the intake port of the head will be slightly larger than the intake manifold, the header flange area will be slightly larger than the exhaust port, etc.

And notice how often steel dowels are use for assembly? Look at how engines use them on the deck surface for the heads, or for the bellhousing, etc.

 

[Jerryl]

This is a good question. Not every setup will allow exact, repeated alignment of a port.

Precision fasteners help. Notice how some manifold makers using 12 point bolts instead of 6 poing ones? It's also why you see 6 point bolts with shoulders under the heads in some locations.

But my gut feeling is that engine builders will open up the area on the part receiving whatever the flow is (A/F, oil, etc.). ..........

And notice how often steel dowels are use for assembly? Look at how engines use them on the deck surface for the heads, or for the bellhousing, etc.

Thanks for the reply.
Not sure if you can use dowels to locate the intake manifold as it may not "slide on"...... at least not if the dowels were square to the surface. (??)

Also, you would want to assemble and align, then drill the dowel hole with the manifold bolted in place ......... I think that would make sense. So, how does one know the alignment is ok before drilling and how does one know how much and where to open the ports in in the head?

 

[Jerryl]

Anyone?
I hope I did not come accross as "I know" but was more "typing / thinking out loud " asking how anyone does this.

 

[Mike Licht]

The only way to change the alignment is to mill the intake or use a thicker or thinner gasket. Then way to check it is to place the intake on and use a bent coat hangar or piece of welding rod to make a pointer
Mike

 

[turbodave231]

I'll tell you how I did a stock intake and heads:

I assembled the heads to the block with head gaskets and torqued the heads, Assembled the intake to the heads with a gasket. I carefully drilled thru the intake at either end with a 1/8 drill bit just into the heads. Be carefull where you do this and how deep you go.

I then used the intake gasket as the template to match the ports. I located the gasket on the parts with some welding rod, scribed the parts and attacked them with the die grinder.

DR

 

[Jerryl]

..... I assembled the heads to the block with head gaskets and torqued the heads, Assembled the intake to the heads with a gasket. I carefully drilled thru the intake at either end with a 1/8 drill bit just into the heads. Be carefull where you do this and how deep you go.

Turbodave,
That is what I was thinking. GREAT advice! :biggrin:

Mike Licht,
Thanks for the GREAT coat hanger advice.
I forgot to mention it is a hot air.

Thanks averyone!

 

[Jerryl]

Just a quick reply to close this thread.
I always thought the port matching (blue printing) is a great idea but if the assembly is off, it will negate all the work done in matching the ports. After weeks of thinking and some experimenting, I found this to work best in the assembly.

With the heads and head gasket mounted, install the intake gasket on the head. I used the valley pan gasket. Besides, it “stays in place” during the intake manifold assembly.


1. Go and purchase some modeling clay at Wal-Mart ($0.99) (See picture)
2. Pick one of the colors (optional) and break off a piece.
3. Mold this piece, flatten it out a bit (0.125”) and make sure it is wide enough to cover the port(s).
4. Now add the clay to the bottom of the intake and stick it on the intake. Be sure to cover the complete port!
5. Cut some plastic strips (from an old bag) and cover the ports. Leave the boltholes in the heads that are used to mount the intake open.
6. Place the head on the motor with the plastic over the ports and the clay on the intake ports of the intake.
7. Lightly tighten the intake bolts in an even pattern in 3 stages to get “even squish”. I went down to 25% of the torque value.
8. Remove the bolts and lift the intake straight up. Be careful not to “wiggle” it off, as it will ruin your reference lines. The plastic and the clay will now be stuck to the intake manifold.
9. Slide the plastic pieces off in a SIDE PULLING MOTION!
10. You can now CAREFULY stick your finger in the intake ports and remove the access material.
11. You now have your reference lines. (See picture)

Hope this helps someone else.


Added in edit.
If you need to know how much to mill the intake, look athis thread.
http://www.turbobuick.com/forums/showthread.php?t=99654

 

[VadersV6]

Why not just look down the runners with a flashlight with the plenum lid off? Its a straight shot down. You can also lightly glue the intake gasket to the intake with the ports lined up right on the intake. Bolt the intake on and spray down the runners with some toolmakers dye. Pull the intake off and you can see whats up. The dye doesnt hurt anything, but if you're worried about it, it comes off very easily with a paper towel and some acetone. You can also fold up some aluminum foil into some squares (make them thick) and lay them over the intake ports. Bolt the intake on, torque it down lightly and the foil pieces will squish into the form of the ports on both sides.

 

[PhilM]

Look down plenum and line em all up (eye, finger, etc)... then just mark the position of the intake on the head using some reference edge on the intake. The gasket, provided your ports match it can just be laid on the head with some sticky and plop the intake on.

 

[Jerryl]

Why not just look down the runners with a flashlight with the plenum lid off? Its a straight shot down. You can also lightly glue the intake gasket to the intake with the ports lined up right on the intake. Bolt the intake on and spray down the runners with some toolmakers dye. Pull the intake off and you can see whats up. The dye doesnt hurt anything, but if you're worried about it, it comes off very easily with a paper towel and some acetone. You can also fold up some aluminum foil into some squares (make them thick) and lay them over the intake ports. Bolt the intake on, torque it down lightly and the foil pieces will squish into the form of the ports on both sides.

VadersV6,
Great advice! This is actually a Hot Air Intake and there is no direct path of viewing to the intake port. I was not worried about any residue dye on the surface, and considered using it but thought it may not give an "accurate and clean" sepearation line. Will try it next time.
The aluminum foil did not work too well for me. I gave up experimenting after a few times. Another great idea though!

Look down plenum and line em all up (eye, finger, etc)... then just mark the position of the intake on the head using some reference edge on the intake. The gasket, provided your ports match it can just be laid on the head with some sticky and plop the intake on.

Phil,
I initially used the intake gasket and pencil marked two points of reference. It worked good (in hind sight) but I am kinda a**l about my assembly.
I wanted to be 110% sure I had it right and the clay I ended up using gave similar results. Thought it was a bit easier though. Another great idea!


In summary;
I purchased a supposedly "ready to go" block but it was "not ready". The block went to the machine shop and while waiting for the block I port matched heads and intake t the gasket.
During head/intake assembly I was thinking; "Let's just verify this for the heck of it". Found that the hot air intake was sitting about 1/8" too high (see pictures) with a stock 87 head gasket on a 109 block! Naturally, one starts looking and questioning "why is it off this much?"

I lapped the heads and intake port surfaces to ensure flatness but I could not have taken off any more then a few thousands in this process. Not sure how much the block was decked previously. The motor has TR hyper pistons with stock rods and zero zero crank, (pistons do not extend the surface )and it would be a near impossibility that anyone decked the blocked that much! So, now I got confused.

Naturally, I wanted to be MORE than DANG sure I was seeing what I was seeing prior to performing any additional custom fitting. Maybe I am just too picky and making things more difficult than they need to be but I wanted some self assurance that it is done right. Better verify the push rods next. :biggrin:

 

[83ttypecooled]

alignment

Hi Jerryl,
I would say it is pretty easy to get those ports lined up. Just keep in mind that the top portion of the intake port should be matching the head's port face.Does that make sense? Hope so. Real easy, right?
How have you been doing, anyway? Give me a call....
Dale