engine decking?

[davek]

1969-440 what are the signs of decking? I bought the Bee around 3 years ago. So the last owner-10 years-was clueless of what was done on the car. Been asking about valley pan problems and not able to get a different intake to bolt up. I decided to sand the pad and I can barely see any numbers on it. Oil pressure is always 90psi and the car never gos above 175 on temp. So if it has been decked I will have to have the other intake decked correct? And if so that means flat bedding the car to the shop or pulling the motor. Thanks guys/gals for all your help.

 

[QuickBpBp]

Probably had some off the deck and had some off the head surface or just a lot off the heads which changes the angle of the port side of the head to the intake. Yes It sounds like the intake has been cut to fit that engine any other intake will need to be cut to fit as you will never be able to seal it and would probably have to hog out the bolt holes to even get them to line up...

 

[Johnpat]

Sounds like heads were ground,not the block

 

[1 Wild R/T]

I do not understand why people cut intakes.... The right way to do it is cut the intake side of the heads.... That way you can swap intakes without a problem & you can move the heads to a different block without issues...

 

[davek]

Probably had some off the deck and had some off the head surface or just a lot off the heads which changes the angle of the port side of the head to the intake. Yes It sounds like the intake has been cut to fit that engine any other intake will need to be cut to fit as you will never be able to seal it and would probably have to hog out the bolt holes to even get them to line up...

Can the shop measure the old intake and cut the new intake or is it better to take to engine in?

 

[QuickBpBp]

I do not understand why people cut intakes.... The right way to do it is cut the intake side of the heads.... That way you can swap intakes without a problem & you can move the heads to a different block without issues...

Exactly it's what I did with mine and I can run any intake with-out issue..

 

[QuickBpBp]

Can the shop measure the old intake and cut the new intake or is it better to take to engine in?

They can probably do it by looking at the intake to see what was done from the stock plane... I am sure you can see it when it's off next to a stock one. All of this should have been done at the start by cutting the intake faces on the head when the machinist was milling the heads or decking the block cause he knew exactly what was done...

 

[1 Wild R/T]

They can probably do it by looking at the intake to see what was done from the stock plane... I am sure you can see it when it's off next to a stock one. All of this should have been done at the start by cutting the intake faces on the head when the machinist was milling the heads or decking the block cause he knew exactly what was done...

When I had my heads done the machinist didn't want to cut the intake side, I had to push for it, give him the amount to cut & I had to borrow a adjustable angle fixture from another non-automotive machine shop that I deal with through my business... For some reason allot of automotive machine shops ignore that step...

 

[dvw]

Some times cutting the intake is either a better option or the only option. When blue printing many things have to be considered. When using a shelf piston you may need a specific deck height. This causes the head to set lower. Obviously milling the head causes it to set lower. You may want to swap intakes on an existing engine that may have been decked or had the heads milled. The heads may have had material removed. Now there may not be enough material left on the intake face of the head to mill. Most times the mismatch doesn't require a lot of material removal. Set the intake on with no gaskets. Does it fit nice? If so remove the amount the same thickness as the gasket. There are formulas for how much to remove from the head face when the head is cut. However if the block has been decked now the intake face needs to be cut even further. The angle already exists on the part. No need for an angle finder.

 

[roadrunner69440]

When I had my heads done the machinist didn't want to cut the intake side, I had to push for it, give him the amount to cut & I had to borrow a adjustable angle fixture from another non-automotive machine shop that I deal with through my business... For some reason allot of automotive machine shops ignore that step...

The angle of the ports don’t change. Cutting the block side of the head just moves the ports down ( closer to the block deck) so the port angle should still be the same? Makes sense to me but I feel like I’m about to be educated lol

 

[roadrunner69440]

The angle of the ports don’t change. Cutting the block side of the head just moves the ports down ( closer to the block deck) so the port angle should still be the same? Makes sense to me but I feel like I’m about to be educated lol

Never mind on my last statement/question, I figured it out!

 

[QuickBpBp]

The angle of the ports don’t change. Cutting the block side of the head just moves the ports down ( closer to the block deck) so the port angle should still be the same? Makes sense to me but I feel like I’m about to be educated lol

No the top grows further apart the more you remove it's widening the angle.. It's all about geometry..

 

[dvw]

No the top grows further apart the more you remove it's widening the angle.. It's all about geometry..

The angle remains the same. Its like looking at a funnel. Same angle but the space between the sides gets tighter towards the bottom.
Doug

 

[QuickBpBp]

The angle remains the same. Its like looking at a funnel. Same angle but the space between the sides gets tighter towards the bottom.
Doug

Yes you said it better than I did but still the same.. Widening the angle.. Angle is the same just bigger at the top you say tighter at the bottom.....

 

[roadrunner69440]

Yes you said it better than I did but still the same.. Widening the angle.. Angle is the same just bigger at the top you say tighter at the bottom.....

Yup so then basically the intake is too wide, unless you take material off the intake side of the head. It all came to me after my first dumb question. Rule #1 think first, ask questions later lol