VE

[Tim Hensley]

Well the short block got hurt in September.Car was a 12.0 and a lot of 11.90@ 112-114mph
The new short block has #1,2and3 caps a DLS forged  rotating assemblies
Ill use my Fullthrottle 206-210 roller cam
My heads were stock I just cleaned up the casting from the flash and sharp edges,stock valves and 3 angle valve job and beehive springs.
Tom at Champion advice is CNC ported Irons, But just a few $100 and Im  in a set of aluminum.
I now the Irons will go 9s and Im just going to go 11.5
With VE being equal between the two,
Weight, hart shape comb. chamber  and Chev type Scorpion Rockers Its a 1 vote for the aluminum heads for me
How many vote Aluminum , how many vote ported irons and how many vote just leave them the way it was
PS a small (very small)chance Ill put this engine in a GenIII and shot for 10s. I have a spear that is stock

[motorhead]

Fuzzy logic much?

[Steve Wood]

Long as you bumped the compression up a point or point and a half, you should be good to go

[Tim Hensley]

Funny 24 hr later it is Fuzzy
The short version,will the better VE in the aluminum or ported irons lessen my chance of detonation?
Trying not to be a slow learner.Iv only had knock two or thee times and never more than 2*KR.
But in Sep.I took out a head gasket #1 rod #1 ,2and 3 main.No KR and o2s in 11.5 range previous 5 passes

[Steve Wood]

aluminum is less thermally efficient so it retains less heat which lowers the power made by the engine unless the compression is raised to regain it.

I suspect the VE is only improved if you push enough air thru the ports to use their capability which is unlikely unless you are headed toward the Nines.

As the aluminum is less thermally efficient, there will be less heat in the combustion chamber and that does lessen the chance of detonation if all else is equal along with dropping the power of the engine...again all else being equal.

It would be pretty hard to convince anyone that iron heads were the cause of your detonation and usually 2 degs of occasional KR on a 11.5 car will not blow a head gasket or take out rod bearings.  Sounds to me as if this was an accumulation of abuse not related directly to that point in time.

[Tim Hensley]

Fel-pro head gasket on #1 gave it up  into the intake not cylinder to cylinder
And with rod and main failure I felt it was knock
I have raced the car two years , last year getting in the 11s
94-075 Leokane St, Waipahu, HI   

[Steve Wood]

sounds like detonation to me...but 2 degs of timing retard is not indicative of severe detonation.  Somewhere, sometime, it has seen much worse than that.

Hopefully all of your injectors are spraying properly

[Tim Hensley]

Dan at DLS made the same statement
I pulled out my logger on the day she went boom
 AFR 11.5-11.3
IDC high 98 just of the brake 95 at the top
My computer gave it up after this pass no log after that but I made no changes
I pulled the plugs nothing looked lean no sight of preignition on #1 or any cylinder
I run a RJC plate all plugs look nice and uniform
Im stumped about how and why it gave up
Im grabbing at straws with VE hopping the hart shaped combustion would help

[Steve Wood]

You are trying to fix a problem with the heads that does not exist.    Something else is wrong.

 Did you check all the injectors to see if they are spraying correctly?

[Scoobum]

Post the log...let's get a look at it.

[Tim Hensley]

Ill post the log tonight
Ill check local to check the injectors or where do i send them?

[Steve Wood]

should be someone in your area that cleans injectors...he re a lot of us send them to Chuck Leeper...the Ol' Buzzard

[Tim Hensley]

$20.00 each just to flow test Im debating to just by new.would be nice to now there flow? I cant get my laptop to connect to my wifi so cant post logs
Ill keep you up to date