Aluminum heads ?

[Highbanked Hauler]

 i think I heard that with aluminum heads you can handle a full ratio of compression.  We figured out that I have a set of old number 12-1 pistons (I know that specks make a compression difference) in my 440. I had planned to run this engine on E-85 but life has changed and I am looking to get this thing comfortably streetable.  Is one brand of head better than another ? Thanks ..

[Challenger340]

  We figured out that I have a set of old number 12-1 pistons (I know that specks make a compression difference) in my 440.

Humor me here OK ?

IMO, highly doubtful you've got Pistons that yield anywhere near "12-1" compression  in the real world ?
So before getting into things like Dynamic Cylinder Pressure/Camshafts Aluminum Head heat dissipation, etc. etc....

what Pistons are you running, and why do you believe they are "12-1" ??

[c00nhunterjoe]

Very simple. What is the "old number"

[Highbanked Hauler]

Very simple. What is the "old number"

   To be up front first, I am not now or ever will be an engine person and I understand the doubt factor. It would be a lengthy story how I ended up with the motor which is a 72 . I got it in 2013 with less than 50 miles on it  from running in the power tour in Detroit and a few burnouts in the street. His car never got finished.

In looking through the spark plug hole I could see the number   ( 7025 )     and .030 which I am assuming is 30 over. There may have been more  # but thats what I could see. It has a Comp Cam with a valve lift of .507 intake and .510 exhaust  with a 106 intake centerline.     906 heads with "long" valves,  1-6 Crane rockers ..

[Highbanked Hauler]

  We figured out that I have a set of old number 12-1 pistons (I know that specks make a compression difference) in my 440.

Humor me here OK ?

IMO, highly doubtful you've got Pistons that yield anywhere near "12-1" compression  in the real world ?
So before getting into things like Dynamic Cylinder Pressure/Camshafts Aluminum Head heat dissipation, etc. etc....

what Pistons are you running, and why do you believe they are "12-1" ??

   Please know I do not have an ego to polish nor am I delusional  nor am I building an 8 sec. car.  Prior post should give you an idea. I am going on what I was told when I got it. I do appreciate any  input.

[John_Kunkel]

I believe 7025P is the equivalent of the TRW 2295 (13 cc dome) which would yield around 12-1 with 85cc head. 0.022" gasket and 0.020" deck clearance.

[BSB67]

Edelbrock 88cc head (60185), and a Felpro 0.051 gasket (1039) will probably get you to where you need to get.  

Your cam selection might matter too.

[Highbanked Hauler]

Edelbrock 88cc head (60185), and a Felpro 0.051 gasket (1039) will probably get you to where need to get. 

Your cam selection might matter too.

  Thanks, do you feel that combination would get it down to the premium gas range ? Can the top of the piston be milled off any ?

[c00nhunterjoe]

For the money you will spend on tear down, milling pistons, and rebalancing, you could buy a better piston. I beleive quench with those pistons will not be ideal, but as stated, it will run fine on pump gas. What head gasketz are currently on it? And are the heads and block cut? If not and running a traditional felpro gasket, odds are it is not a 12:1 mill. If you have the cam card or at least grind number, get some cranking compression numbers and post.

[Highbanked Hauler]

     I would agree on the under 12-1 as the owner said he drove it about 100 miles in the power tour and I asked him how did he get race gas in the city and he said  HE DIDN'T.
  At a glance aluminum heads go from $1000 to $2000 a set and the pistons I saw were $700 plus rings, keepers and whatever else. So pistons would be half the price of heads but the motor comes out and apart. I am $2600 into the motor so it could be worse.
 
   PART # 21-225-4
GRIND NUMBER CRB XE284H 10    ? Comp Cams

  Compression I will have tomorrow.

[Challenger340]

whoooaaa !
Hold on there... that's what I figured.... and you are nowhere even close to 11:1....  let be 12:1
7025 are indeed identical to the L2295 Speed Pro, in fact TRW and Speed Pro used to use the same Forgings back in those days.

They are 10.37:1 Compression Ratio using an Fel-Pro Composition Gasket (.039") and an 88 CC Cylinder Head installed in a 10.72" Deck Height UN-Milled Block.

Meaning, that unless your Block has been Milled fairly extensively ?(like more than .010").....  those Pistons are still .050" to .060" down hole at TDC and you are likely still well below 10.5:1.

Here are the L2295's same as your 7025's
https://www.summitracing.com/parts/trw-l2295f30

As mentioned....
* disable the ignition
* wire your throttle plates wide open
* remove all 8 Spark Plugs
* install a decent quality compression tester in each cylinder one at a time
* Crank Engine.... allow 4 Bumps ONLY on the Needle per cylinder.... try and note the 1st "bump" as 75% of the 4th and FINAL "bump" and record that 4th Bump as final pressure for that Cylinder.

Report back.

[firefighter3931]

Yep....the 2295's sit .050 below deck so with a std .040 gasket and 84cc E-head the comp works out to ~10.5:1 

I know someone who ran that exact combo with a Comp Solid 294S cam and it had plenty of piston to valve clearance. 


Ron

[c00nhunterjoe]

Yep....the 2295's sit .050 below deck so with a std .040 gasket and 84cc E-head the comp works out to ~10.5:1 

I know someone who ran that exact combo with a Comp Solid 294S cam and it had plenty of piston to valve clearance. 


Ron

I like that grind cam. Alot of street guys think its too big.... glad to hear it still used.

[b5blue]

 Just to answer your original question after my build I chased ping/knock and aluminum heads finally cleared that up. I used Sidewinders:
http://www.mopartsracing.com/parts/Sidewinder.html
Real happy with them using 750 with CH4B-HP exh manifolds and Mopar Road Runner cam. 

[Highbanked Hauler]

Yep....the 2295's sit .050 below deck so with a std .040 gasket and 84cc E-head the comp works out to ~10.5:1  

I know someone who ran that exact combo with a Comp Solid 294S cam and it had plenty of piston to valve clearance.  


Ron

I like that grind cam. Alot of street guys think its too big.... glad to hear it still used.

 So since it is established that mine is 10.5 comp. (which is great)  then a "thick" head gasket this thing should be getting down in pump gas range right ? Thats what I am after. The cam number is posted from the paper I have.  

Compression gauge is dead..

[Highbanked Hauler]

   I am in the process rebuilding NOT restoring the car, it  is NOT  on the road. and I use 93 to start it       New compression tester   was to long to get past a couple of tubes

  COMPRESSION   No. 1   90  150  180  187    No 3   header in the way        4 bumps count               cam numbers on a prior  post

                         No 2   100   120  180  185   No 4  100  130  180  184         Carb. off of the motor    The third bump was consistently  180

                          No 5  header in the way      No 6  header                            all plugs out
   
                          No 7  90   150    180    185  no 8   90   120  180   185           ignition unplugged

      1.6 Crane rockers.                                                                                                                                         

[c00nhunterjoe]

We are educated guessing the numbers based on 3 main variables still. We either need compression numbers to get it accurate or it torn down to measure before you can go much further with reccomendations. ASSUMING it is 10.5:1, that is pump gasable on iron heads 98% of the time. What fuel are you currently running and why do you not run  93? Really need those compression numbers.

[Challenger340]

Still a TON of variables that need to be nailed down more precisely BEFORE making Fuel grade decisions ?

Get some compression numbers on whatever current Camshaft is in there ? I must have missed it... WHAT cam is in it ?
or,
tear a Head off and MEASURE how far down the flat portion of the Pistons are at TDC ?

"Quench" plays an important role when approaching the limits of the fuel, and although I dis-agree with many around optimum quench being "sub-.050" on all BB Mopars ?....
that said,
if your Pistons(flat portion) are indeed .050" down at TDC and 10.5:1 Compression Ratio is attained using a .040" Head Gasket.... then your TOTAL "quench" of .090" (.050 + .040) is a little high.... and I would suggest an Elevation/Dynamic Compression limit with whatever Camshaft profile closing point of around MAX 155 psi for 91 Octane Pump Fuels on a full timing curve(34*/36*).

[Highbanked Hauler]

   I am in the process rebuilding NOT restoring the car, it  is NOT  on the road. and I use 93 to start it       New compression tester   was to long to get past a couple of tubes

  COMPRESSION   No. 1   90  150  180  187    No 3   header in the way        4 bumps count               cam numbers on a prior  post

                         No 2   100   120  180  185   No 4  100  130  180  184         Carb. off of the motor    The third bump was consistently  180

                          No 5  header in the way      No 6  header                            all plugs out
   
                          No 7  90   150    180    185  no 8   90   120  180   185           ignition unplugged

      1.6 Crane rockers.                                                                                                                                         REPEAT

[BSB67]

Edelbrock 88cc head (60185), and a Felpro 0.051 gasket (1039) will probably get you to where need to get. 

Your cam selection might matter too.

  Thanks, do you feel that combination would get it down to the premium gas range ? Can the top of the piston be milled off any ?

Yes.  It can be, but you don't need to.

[BSB67]

   I am in the process rebuilding NOT restoring the car, it  is NOT  on the road. and I use 93 to start it       New compression tester   was to long to get past a couple of tubes

  COMPRESSION   No. 1   90  150  180  187    No 3   header in the way        4 bumps count               cam numbers on a prior  post

                         No 2   100   120  180  185   No 4  100  130  180  184         Carb. off of the motor    The third bump was consistently  180

                          No 5  header in the way      No 6  header                            all plugs out
   
                          No 7  90   150    180    185  no 8   90   120  180   185           ignition unplugged

      1.6 Crane rockers.                                                                                                                                         

I'll still stay with my original recommendation, considering the information we have at this time.  But I would not buy anything until you pull a head and start measuring.  If you had an aluminum head on it now with a blow of 185 psi, you would probably get away with pump gas with the right tune.

But for sure, between the head selections that are out there, and the head gasket options, you can probably get nearly any CR you might want. 

[Highbanked Hauler]

 So what is the thickest gasket that can be used because I would rather not by aluminum heads I am on damage control now.

[cdr]

So what is the thickest gasket that can be used because I would rather not by aluminum heads I am on damage control now.

you need alum heads In my opinion.

[BSB67]

So what is the thickest gasket that can be used because I would rather not by aluminum heads I am on damage control now.

you need alum heads In my opinion.

Probably Right.  Its going to take more than a head gasket to get down to 160, IMO.  What gasket do you have know?

[Highbanked Hauler]

So what is the thickest gasket that can be used because I would rather not by aluminum heads I am on damage control now.

you need alum heads In my opinion.

Probably Right.  Its going to take more than a head gasket to get down to 160, IMO.  What gasket do you have know?

The engine was complete when I got it, I just bolted stuff to it. As I said I was planning to run it on E-85 so I didn't think compression was an issue but that was 7 years ago and life has changed.    So it comes down to pistons  right ?   CAN aluminum heads compensate for the compression if thats the issue ?