Has anyone Ran the 903A heads?

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Has anyone Ran the 903A heads?

Post  nathan mann on January 17th 2012, 8:54 pm

Has anyone ran the IDT 903A heads? If so how did they perform? How much power do you think a 625ci motor with TFS tunnel ram (short runner)with around 11.5 to 1 compression (for street driving) make? I am thinking about building this combo for Hot Rod mags Drag Week.I have always built and ran small blocks this will be my first Big Block.

Thanks in advance for any replys.

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Re: Has anyone Ran the 903A heads?

Post  BOSS 429 on January 17th 2012, 10:14 pm

nathan mann wrote:Has anyone ran the IDT 903A heads? If so how did they perform? How much power do you think a 625ci motor with TFS tunnel ram (short runner)with around 11.5 to 1 compression (for street driving) make? I am thinking about building this combo for Hot Rod mags Drag Week.I have always built and ran small blocks this will be my first Big Block.

Thanks in advance for any replys.



THE ELIMINATOR 903 HEAD IS A very good verison of an a head, im doing an engine now with them. the porting work has to be spot on for an engine of your size with this head for max power.
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Re: Has anyone Ran the 903A heads?

Post  cool40 on January 17th 2012, 10:22 pm

i have not ran mine yet but i can tell you the flow #'s are what they say.
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Re: Has anyone Ran the 903A heads?

Post  LETHAL_DOSE on January 18th 2012, 10:34 am

Yes, I have a set of the 903 series Eliminator heads on an 526 ci pulling engine. When I had this engine dynoed about 6 years ago, it made 940 hp @ 7300 I think, I forget the exact torque numbers. I ran it that season and it seemed to be lacking on the big end. It would just die instead of pulling down and continuing to pull. That off season, I milled the heads, put new pistons in it (due to melting a couple), and changed where the cam was degreed in at. That next season it was entirely different animal. It would spin out now and continue to pull. I had the heads down to see Charlie a couple years ago and he fixed a combustion chamber where a valve decided it wanted to try to exit, and put all new titanium valves in. Charlie picked up quite a bit of flow through the mid-range (I'm thinking like 30-35cfm on avg between .400-.700), and a little up top as well (I have the flow sheets at home). They do flow good; over 500 cfm is where they peaked.

I have not had it back on the dyno, but it will be in a couple months. I am switching from alky carbs to injected alky, and will put it on the dyno to get the fuel curves set.

Mike
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Re: Has anyone Ran the 903A heads?

Post  rmcomprandy on January 18th 2012, 11:07 am

LETHAL_DOSE wrote:Yes, I have a set of the 903 series Eliminator heads on an 526 ci pulling engine. When I had this engine dynoed about 6 years ago, it made 940 hp @ 7300 I think, I forget the exact torque numbers. I ran it that season and it seemed to be lacking on the big end. It would just die instead of pulling down and continuing to pull. That off season, I milled the heads, put new pistons in it (due to melting a couple), and changed where the cam was degreed in at. That next season it was entirely different animal. It would spin out now and continue to pull. I had the heads down to see Charlie a couple years ago and he fixed a combustion chamber where a valve decided it wanted to try to exit, and put all new titanium valves in. Charlie picked up quite a bit of flow through the mid-range (I'm thinking like 30-35cfm on avg between .400-.700), and a little up top as well (I have the flow sheets at home). They do flow good; over 500 cfm is where they peaked.

I have not had it back on the dyno, but it will be in a couple months. I am switching from alky carbs to injected alky, and will put it on the dyno to get the fuel curves set.

Mike

"Melted a couple pistons" - I would conclude that at least your tune-up was not right and those before numbers are immaterial.

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Re: Has anyone Ran the 903A heads?

Post  LETHAL_DOSE on January 18th 2012, 11:25 am

The guy that built the enigine did not give it enough piston to head clearance. The piston was hitting the head in between the valves, which caused a sharp point on the piston. In turn the piston started to melt. They did not melt bad, just started to melt where the pistons had a sharp point.
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