Milling and Valve Work

[Silver3800V6FBodyKY]

I'm having my heads Ported and Polished by Riggs Racing Heads. Is it worth it for me to have my heads milled @ .050", and a 3-angle valve job? How much more power is that going to give me than just the port and polish?

Also, this is off subject but still, what is the correction factor for dynoing after having gone from 3.42s to 4.11s?

Thanks guys.

[John_D.]

<blockquote>quote:</font><hr>Originally posted by Silver3800V6FBodyKY:
Is it worth it for me to have my heads milled @ .050", and a 3-angle valve job? How much more power is that going to give me than just the port and polish?<hr></blockquote>

Hey I don't have the hp numbers for you, but I do have a thought...

Milling will raise the compression ratio, and if you are still thinking about going with a supercharger sometime down the road, the higher compression ratio will be a bad thing.

[pgriffith]

if you mill that high you will have to mill the intakes. Safely mill is about .020

[Silver3800V6FBodyKY]

For the cam I've chosen,

212/216 .500"/.500" 112LSA

How much would I need to mill the heads in order the keep using the stock pushrods? I have no idea how to find out that number, but my whole point is to keep using the stock V-train.

[pgriffith]

Call comp, I believe they make there extreme energy cams to use stock pushrods. I asked them and thats what the guy said, I have no idea if he knows what he is talking about. So if this is true you will be able to use stock pushrod if you dont mill the head.

Magnus uses a compcam, I am curious as to what size pushrod's he uses. I know they are trickflow chromoly and 5/16 but what length are they?

I know you can get an adjustable pushrod that you can use when you have the cam and heads installed, its a good tool for measuring the correct length of pushrod. I think we are supposed to have 30 lbs. of preload on the valvesprings, if the pushrod is too long it will be loud, if its too short it will be quiet but rob power.

Another way is to compare the stock cam to the compcam and measure the lobe sizes then do the math.

again Magnus what size are your pushrod's, are your heads milled?

[WickEdSix9838]

angle milling the heads .050 will pick it up quite a bit, compression is worth a LOT of power, and you dont have to mill the intake, you mill the intake surface on the heads, and normally a valve job is a part of the port job, you might as well do a valve job while you got the heads off...my dad is a head porter and has some of his own 5 angle radius valve jobs that will normally by just doing a valve job to some Brodix or Dart heads pick them up 10-15 cfm...plus the valves need to seal real good so your not bleeding off any compression...you can check if they seal by pooring laquer thinner into the ports and she if it leaks through into the combustion chamber...

[12secondv6]

Well, whenever I've had headwork done I got the following done:
3 angle valve job
bowl or pocket porting
milled 0.010 over
full port and polish
on the intake runners there is a large area inside that can be ground down for improved flow.
N/A I don't think I really noticed much because I kept the stock cam.
The car was running leaner after it so I richened it up with my afpr, but I think a bigger fuel pump would be fine (Although I haven't tried this yet).
On the bottle though it really picked up.
If you have the heads off I suggest porting the upper and lower intake manifold.
Leave the TB stock.


Gears will not affect dyno results. The problem is you will hit your speed limiter much sooner and you will not be able to pull a full dyno run.