magnum hds

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388dart

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'What flow numbers could I expect out of a set of mildly ported Eddy magnums?
What performance gain/loss might I expect from my 388?
Presently:
CI 596hds w/SS202/1.625 11/32 stem ucvalves, 67ccs, ported, gaskt mtched
Calculated 10.7CR
RB cam 264*@.050 I.555/E.520
Airgap w/ 750mighty demon

It runs great up to ±5700rpm and then seems to fall off ie. quit pulling as hard after the 1000' area at the track.

With the magnums the CR goes to 11.9 but aluminum and the cam lift will be the same .555"
 
I think for any engien bigger than 3665", I would rather use the Magnum R/T head from MP. I'd order the bare castings, and go from there. They are slightly bigger volume wise, and IMO have a better looking chamber. PLus, being made from iron, will make more power. The down side is the chamber size is a bit smaller than what you have. Small chamber + iron = detonation issues with them. What pistons do you run now? Did the heads you have ever get flowed? I dont think the Edelbrock magnums will do much better in the higher rpms like you're looking for.

As far as Ryan goes, I have heard many more good and very good things about him than bad. But I know of a few issues customers of his had that I have spoken with. I'll bow out from really judging his work, as I haven't held one of his heads in my hands. I'm sure I know less than he does about small blocks. I know there are others who disagree about some of what they have seen from Shady Dell like BJR tho... My $.02...
 
BJR Racing said:
Rumble,
I have some stories for you on Ryan, and I leave it at that.
Click to expand...
He asked;
'What flow numbers could I expect out of a set of mildly ported Eddy magnums?
Click to expand...
For a reference point, I had no other source at my finger tips to give.
Please post yours away.
 
I agree with Moper on the iron heads over the eddy's, but depending on 388's centerline and overlap on the cam will depend on weather the engine with detonate or not as cylinder pressure could fall off greatly depending.
As for flow #'s this is what we have come up with just doing bowl work and gasket matching, with a 2.02 valve and a 1.62 exhaust valve, and the exhaust was just bowl blended and no other port work and a good valve job on both sides.

lift I/E
.100 91/79
.200 177/119
.300 225/150
.400 245/193
.500 248/204
.550 250/207
.600 272/209
.700 272/210

Alot has to do with the type of valve used, finding the right valve is as hard or harder than the right head, this is why I do alot of remachining on valves to get what I need. Ferrea IMO has the best designs to start with.
 
Hey, nice results. That would work real well on a street machine. Have you ever had a chance to go full out on a set of Magnum heads?
 
The pistons are forged Fts @ -.003 deck ht.
Cam is [email protected] 105ICL, 111ECL, 108CL installed 3* advance, .560" I&E lift
IO22* IC52*, EO58*, EC16* It bleeds off compression big time at lower rpms, but sure provides a lot of snap above 2500. 430 gears help in that respect too.

With the magnums I will have .037" quench and 11.9 calculated compression w/ 58cc aluminum heads. I'll be CCing a couple of chambers tonight to make sure.
thanks for the feedback. :salute:
 
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