what is your opinion this combo?

-
D

DusterMex

Member
Joined
May 9, 2006
Messages
19
Reaction score
0
Location
Mexico City
Hi, what is your opinion this combo for a Duster? And how many HP?


360 over .060
Pistons KB dome 11.20cc
Rings Speed Pro Plasmoly
Comp Cams kit Cam/Lifters/Valvetrain, Hydraulic Flat Tappet, Advertised Duration 280/280, Lift .480/.480, Mopar, 273-360
Timing Chain Double non-roller
Stock cast iron Magnum heads porter and polish (in home) Valve Ferrera 2.02 y 1.60
Rocker Arms, Shaft Mount, 1.5 Ratio, Aluminum Proform
Headers Headman Full-length 1 5/8 in
Manifull Weiand Excelereitor
Carburador Holley Stree Advantage 670
Summit X-Pipe Kits
Sealed Power High Volume Oil Pumps
Orange Ignition Control Units
Mopar Performance Vacuum Advance Electronic Distributors

Thanks from Mexico.
 
Other than the x pipe I thought that you were talking about the combo that I built about 4 years ago. I ran almost that exact same combo and let me tell you what. Hang on. Cuz its gonna get you there now. Leaving in 2nd gear the car ran a 13.94 @ 104mph in the 1/4 with a 3.91 gear in my Duster. It was as good as you could get with that kind of motor to drive every day and I did. Great combo. I would run a single plane intake on that motor to help kill some of the bottom end and put a little more on the top. Have fun with it. I did.
 
Do you have all the listed components purchased and in your possession?
If yes, it will be a good combination. If not, we might be able to make it an even better combination.
 
I finished build the engine, but I have some problems, I thing that the piston touch the top of the head, When the engine begin to warm, begin little noise similar rocker arms.

I suppose that the quench pad of the piston elevated 0.050 in touch the head, my head have the combustion chamber like a heart and my head gasket is 0.039 (felpro)

It is possible?
 
It is possible - is the flat of the piston above the deck? If it is zero deck height .039" gasket thickness should be adequate. What rods do you have?
The other thing to look for is any rubbing on the pushrods. Magnum heads are set up for 1.6 stud mount rockers. I think you mean you have 1.5 stud mount rockers which will put the pushrod closer to the intake side of the pushrod clearance hole in the heads. Secondly, you are running a flat tappet cam which makes the angles even worse with the magnum heads = check pushrod clearances at closed and open lifts for rubbing/ interference.
What initial advance and total mech advance do you have? What rpm do you have total mech advance?
 
I was just going to bring that up...Domed pistons designed for an open chamber if set up properly in the block (meaning near 0 deck) will hit a non open chamber design head. I'm also curious in what your machinist told you for compression. Magnums come at 55-60ccs IIRC. With a dome, you will have much higher than 11:1. You need to check your piston to head clearance..DO NOT RUN it anymore until you pull a head and look. If they are hitting, the rod bearings need to be inspected at minimum.
 
moper said:
Magnums come at 55-60ccs IIRC.
Click to expand...

Stock magnum heads are around 64cc. The two sets I have had both cc'd out between 63.5 and 64.5 cc's.
 
Hi, and apologies for my ingles


388Dart: the pistons are KB #UEM-kb191060-8 http://store.summitracing.com/partd...890201+4294891059+4294776938+115&autoview=sku
this piston have 0.150 in. pop-up crown design with 0.050 in. elevated quench pad. The rods are stock and I wrong my head they aren’t mangnum, I don’t know exactly their characteristics are: the Spark Plugs is the same a Ford (big hole) add some pics of the head:




The timing: total 32 with 92 oct, 36 with 110 oct, here in Mexico is 8,202 feets.
The RPM 6,000

MOPER: I can’t calculate the compression radio yet, because I don’t kwon the combustion chamber (cc) of my head. When I put the head without gasket and move the engine, the pistons touch on head and then put the gasket and move the engine don’t touch. Add pic from the pistons.



Thanks
 
Make these changes:

1. get a thicker Cometic metal shim head gasket.
2. get a better cam. Call http://www.hughesengines.com/ and ask them for the best cam for your setup.
3. Get an Edelbrock performer RPM air-gap.
You should be able to hit 425 HP easy with a mild HEH1928AL cam.
 
You definetely have a problem. Do not run any more until it is determined what exactly you have.With those pistons and a 64 cc head you have a compression ratio of ±13.2 - and to me the CCs of those heads look smaller than the Eddy magnums I have and they are 58cc. You could have as high as 14.:1Compression.
As you have said they have .050 above the flat of the piston for quench pad and then another .150 dome = very high compression .
Those pistons are not meant for close chamber heads - unless you want 14:1 CR
Are they CI heads? or Aluminum? see if there are any numbers on them somewhere? or manufacturer - Mopar, Edelbrock, ???

I suspect at the very least the back side of the dome is hitting on the head as the engine is warming up - I saw the exact same problem with an engine here in Calgary.

Is it your plan to have this as a mainly street driven car - or strip race car?
What is highest octane of gas you can get in MC?
 
Those are not Magnum heads. They might be some of the late 80's swirl port heads from the looks of the chambers, they don't look aluminum to me. You also have to remember that he is in Mexico City, they built different cars and engines in Mexico and S. America, those might be a type of head that was not available here in the states.
 
You can tell they are not magnum by the intake bolt holes, pedistal mounts, and valve cover bolt holes.
 
I think this is more the type of piston that should have been used.
KB373 CHRYSLER 360 6.123 2.75c 2.75cc/Step . >080" quench pad is to be machined to obtain the desired .040 quench - provided the top of the piston is not sitting above the deck already.
At your elevation you could likey run 10.5-11.0:1 CR on pump gas, but 12.80-13.2 no way.
 
Thanks for clarifying on the cc's Dave...

If you want to run those heads, you will have to get different pistons. I'd run flat tops in that setup. It must be a different export head..Never seen the big plugs in a small block before..
 
Yo whats the casting number on those heads. Look like something good to look for in the salvage yard next time I make a visit.
 
MING! Look at those slugs! WOW! Sweet.
Looks like a thicker gasket is needed.
Or the short block goes back to the machinest to mill the pistons down to fit.
Then a re-balancing of the assembly is needed.
 
You must log in or register to reply here.
-

Back
Top