cylinder head and cam ID

[Kizilsakal]

Ladies and Gents

I have 2 cylinder heads and 2 cams in them that are not the original ones for my E9 engine.

anyone know how to identify these?

Thanks

 

[sfdon]

Head?
Early ('70's) and late ('88+)heads
Note the shape of the intake ports
Late head has the third and final port shape.
Cam?
Need to see the number or letter on end of cam.
Remove cam plate at back of head
There will a "K" on the later heads cam and a number on the early head unless they were swapped for a performance cam

 

[Kizilsakal]

Head?
Early ('70's) and late ('88+)heads
Note the shape of the intake ports
Late head has the third and final port shape.
Cam?
Need to see the number or letter on end of cam.
Remove cam plate at back of head
There will a "K" on the later heads cam and a number on the early head unless they were swapped for a performance cam

Thanks Don,

Their combustion chambers are also a little different. would they both work with my engine?
I will take a picture of those too.
Also I noticed the size of the banana intake tubes don't exactly match the intake ports, is that normal?

Take Care

 

[sfdon]

There are 3 intake port shapes
3 different gaskets
port match the shape of the stub manifold to the shape of the intake port of each head.

 

[sfdon]

Pic for you.

 

[Kizilsakal]

Thank You Don.
will do

 

[Kizilsakal]

I have checked and both cams have number 7 on them.

2 heads differ in combustion chambers, valve sizes and holes for coolant to pass

I will check the volume of the combustion chambers tomorrow.

 

[sfdon]

what car is the head going into?
I need another picture of the late head

 

[Kizilsakal]

It's going into a 1972 E9 CS.

 

[sfdon]

It’s no good. Sorry.
It’s below minimum spec.
I would guess 10 thousandth of an inch less than minimum

 

[Gransin]

It’s no good. Sorry.
It’s below minimum spec.
I would guess 10 thousandth of an inch less than minimum

Don,
I’m not questioning your statement, just asking because I would like to learn something new.
If a M30 head is a couple of thousands below minimum spec, what’s the biggest problem with that?
Valve - piston clearance?
Crankshaft - camshaft out of sync?
Timing chain not tensioned enough? (Tensioner too far pushed out)
Something else?

 

[sfdon]

You can buy a slotted camgear to address the crank/cam timing.
But you have to pay for it and know how to install it.
Not a deal breaker...
You can still use a aftermarket cam if you clay the head first if you know to do that.
If it still has clearance it’s not a deal breaker
But when you over heat that head and have to look at the client and tell them they need a completely new head because you sold them or installed a marginal head and now they need to pay 2000.00 extra it’s big ass deal breaker. Pro’s don’t install beater heads on their last legs.

 

[Gransin]

Thanks for the informative answer! Yes I understand that a pro both recommends and wants some tolerances

 

[sfdon]

If you use the 89 skinny shaved head on a early block your compression will be bad.
Don’t go there. That head is for a b35 Engine.

 

[Kizilsakal]

Thanks Don,

How did you notice that it is skinny?

There is a small crack in the older head. So i guess i need a new one.
When you say compression will be bad do you mean too low or high?


Thanks

 

[Markos]

Thanks Don,

How did you notice that it is skinny?

There is a small crack in the older head. So i guess i need a new one.
When you say compression will be bad do you mean too low or high?


Thanks

Compression will go down. The B35 head has a bigger combustion chamber. Bigger valves also but the compression loss negates that advantage.

 

[autokunst]

I am very much enjoying following this thread. Great learning opportunity from the masters. I understand that the larger combustion chamber results in loss of compression, negating the larger valves. Although the original poster is not asking this, couldn't that compression be maintained if different/domed pistons replaced the originals? Of course, maintaining valve-to-piston clearance. Not sure what the math would be, but perhaps that still doesn't result in tangible benefits?

 

[Kizilsakal]

Compression will go down. The B35 head has a bigger combustion chamber. Bigger valves also but the compression loss negates that advantage.

Yes, but a shaved head also loses some volume from the combustion chamber. I will measure the volume.
the problem becomes valve clearance and strength of the head I am guessing right?

 

[Markos]

I am very much enjoying following this thread. Great learning opportunity from the masters. I understand that the larger combustion chamber results in loss of compression, negating the larger valves. Although the original poster is not asking this, couldn't that compression be maintained if different/domed pistons replaced the originals? Of course, maintaining valve-to-piston clearance. Not sure what the math would be, but perhaps that still doesn't result in tangible benefits?

Honestly unless you are striving for an original block, it would make sense to just upgrade to a factory B35 before sticking custom pistons in your 3.0. You can always turn your original block into a coffee table.

 

[Stevehose]

Looks like the dimple is gone which indicates it's been shaved

Thanks Don,

How did you notice that it is skinny?

There is a small crack in the older head. So i guess i need a new one.
When you say compression will be bad do you mean too low or high?


Thanks