What sort of flow increase could i see on my RPM's ? i'm thinking of having the intake opened up to match my indy intake and having them milled to 65 cc.
Mick

Flow increases are measured at valve lift,milling to 65 cc will increase the compression.What heads,what intake and what starting cc volume?We need more info.

heads are 76cc, already ported and milled .050 by MCH, the intake i'm looking to use is indy max wedge.

Are they Indy heads? If so you should see an increase in compression by 1 point. ie: if you were at 9.5 you have increased to 10.5.

Motor is a 470 low deck with 440 -1 heads with just a clean up 78cc, it has .060 cometic gaskets and a herbert .590/.610 255/265 roller cam. I personally think it may be no faster than my old 440 with a .590 cam in my sig below.
So i'm wondering if swapping to my old RPM heads with the above mods and .040 gaskets, along with a a bigger cam i have .625/.625 275/283, will get me the power i'm looking for to drop the car into 9.80-90's.
Mick

With the 440-1 heads you should try more cam.Something like a 650/650 in at 108 CL.If you have enough P/V and P/H clearance try a .020 steel shim or .031 head gasket.9.80 or better should be easily reached.

What's wrong with the bigger roller i already have ?

It is a little small but should get you in the 9'S
I'd get all the compression you can get.
The -1s should make more power then rpms.
The -1s WILL Also Like More cam

My 528 with 440-1 heads likes 7100 rpm shifts. A 470 is going to want more rpm, if they are ported and your other parts are suitable for max power. I would run the 275/283 cam but look for rocker arms to increase the lift. Ported, those 440-1 heads will like as much lift as you can throw at them up into the .800 range. You may not want to shoot for that much lift, but getting the NET lift over .700 should pay big dividends. You didn't say what stall you have, (assuming an auto) but 5500 to 6,000 rpm as a minimum is where I would start.

You can use your existing roller cam and 1.6 rockers for additional lift.Keep you cam under or near 700 lift to have a combo that is not hard on parts.

My Isky roller is .680-.660 and 276-281@ .050 and went 9.79 first pass at 3200+ lbs so is my cam too small? And my rpm`s are just a tad bigger than stock on the intake but fully ported...........

Greg
Converter stalled at 5000 behind my 440 in sig, i would think it's going to stall higher behind the 470.
Dom
That's why i thought about using my RPM's but have them milled a bit more to get the comp over 12.1 then use the bigger cam but the indy intake is max wedge so i assume i would have to open the RPM's up to max wedge.
Mick

I think Dwane porter and others have a program for the max wedge intake port and many have enjoyed the results cos it`s more involved than just an "entrance" to max wedge size as I understand it and needs to go in deeper to get the flow results/benefits..............

Yes i knew that, one of the heads needs repairing anyway, so it will be going back to MCH for that, they could open the ports up and mill a bit more off to help with the comp.
Mick

Jeff @ Modern RIP, has done them both ways. The difference was about 10cfm. But cfm doesn't show the whole picture. The extra column port capacity can help sometimes too, but not always.

Porter racing saw about the same flow between the two from a untouched intake opening runner and one that was opened up. As I recall from a PM from him.

Just because you can open up a RPM to nearly MW sizes doesn't mean it will port match a true MW intake. The center port divider is wider on a true MW

The indy MW intakes can be To much intake on a engine like you describe.

This is the sort of info i was looking for, i was looking at my rpm's today and couldn't understand how they could be made larger with such a small amount of metal between the two ports. i'm not looking to reinvent the wheel, i just want the most economical way to make this motor more efficient without throwing half of it away.
Mick

Keep in mind guys its not usually the pinch (port entrance) that is what's limiting the air flow. Throat dimension and short-side area work is what pays the big dividends.

Personally, since you have the -1's already, I'd just use them.

Mill them to 68-70cc, will put you at about 12:1 on a zero deck flat top 470.
That should work fine with the cam you have.

Not saying Edelbrock heads won't run great. My Friend has gone 8.80-s with Edelbrock heads and a solid lift cam in his Duster. On a bad day at PRP he goes 9.0's

Just use this for way of encouragement with the RPM heads. On a set of RPMs I opened the port entrance to 2.580 X 1.330, they were kinda bell mouthed around the pushrod side and the top of the port. Used an Indy Single plane. Ran a cam, 276/280 @ .050 w/ .800" lift. The 451 stroker had 417 LB-FT @ 3,100 rpm, 503 LB-FT @ 3,500 rpm, 574 LB-FT @ 7,200 rpm and, oh yeah, 787 HP @ 7,200 rpm.

Those RPM heads will work.

Yes the RPM's can make good power....... But they're damaged(and not MW size yet), he lives in the UK, and he has a set of ported 440-1's just sitting there.

Yes, you are absolutely correct, the 440-1 are the better solution. I may have muddied the waters there. Of the two, I personally would rather start with the 440-1. I won't buy another set of RPM heads until they get the casting slop/shift corrected and get rid of that giant hole that feeds the rocker shafts.

I've used a set of CNC MCH ported RPM on my old pump gas Duster, those heads flowed 310 CFM at .700 on Pettis Super Flow 600 bench at 28 inches of water.I swapped those heads to a set of Indy SR M.W. ports that flowed 340 CFM on Pettis flow bench at .700 lift at 28 inches of water, I had another set of Indy 440-1 that I had MCH CNC port and thoses flowed 370 at .700 on Pettes bench. My car ran 10.30s at Woodburn with the Eddy RPM heads, it ran 9.993 with the Indy SR heads and a Indy 400-3 intake with a 1050 Dominator. I had dyno tested my pump gas motor with all three sets of heads on them, there was right at 30 HP gain between the Eddy RPM and the Indy SR, there was right at 55 HP gain from the Indy SR to the CNC ported 440-1 using the same carb, intake jetting and both sets of the Indy heads had 75 CC combustion chambers so the compression ratio stayed exactly the same. Thar CFM difference made the HP gain and raised the peak HP RPM by several hundered RPM
My message is to run the big heads with a matching intake port manifold

I have a feeling you won't be using RPM heads for a while then. I'd be very surprised to see Edelbrock make any adjustments to those heads....... And I agree, the core shift situation is pretty bad. And not just on RPM heads either, I have a set of BB Victor heads here that are pretty ugly.

On the last Victors, because of the core shift and the oil supply hole being drilled crooked, I had to sleeve the oil supply passage. I called and told them about my problems with the Victor & RPM heads. They said they would get back to me right away. It's been about 4 months now.

The motor has the 440-1's on it at the moment along with the indy intake and don't forget these heads are pretty well out the box and the RPM's are already ported and milled by MCH and have run the time in my sig with a purple shaft cam.
I think initially, i will change the gaskets for .040 or maybe even copper coated steel shims and run it as is for a base line and if it's no quicker than the old motor then look at ways to get some extra power.
Dwayne the RPM's are going back to MCH to be repaired, i was just deciding what to do with them before i sent them.
Mick

I suspect if you run it with the lower compression and the small cam, it won't run as fast as it did with the old motor.
If that's the case, you can either use that as an excuse to reuse the rpm heads, or as an excuse to work on the -1 combo...... The choice will be yours.

I would use the 440-1s myself with the steel shims, to get the most compression, if you have the PTV clearance. The two heads are 2 cc,s apart from what you stated. Don't know the deck height differences between the two motors, 440/470?? If they were the same, with the extra stroke of the 470 makes the differences of the head cc of a 2cc difference, not a issue.

On the Eddies, They are more then enough to make the power you need, but they are or one is messed up or so.. I would not have them milled down to 65 cc,s. That open ups a whole another can of worms with intake fitment and pushrod length, etc. Just get them fixed.

What is the problem with them by the way? Damage from the old engine blow up or something else?

Dwayne
You may well be right, although the .040 gaskets will lift the comp a touch and the 4150 HP 1000 will be swapped for my 1050 Dominator, so we'll see.
Mike
Untill i get the heads off, i won't know if i can use the shims, the motor was originally built for enginemasters with 383-13 heads flowing 400 cfm milled to 65 cc, motor was 13.1 comp and made then 735 hp with a solid cam, i am going on the assumption that the block would have been zero decked, which if so , will rule the shims out due to piston to head clearance.
My motor leg go last autumn, a hole in both sides of the block cam snapped into 4 pieces, one of the heads was damaged on the mating surface and also a little damage in the combustion chamber. One of the valve spring was lying in the head and one of the locks was missing.
See pics
Mick

I don't know what it costs to ship heads back and forth from the UK to the states, but I have to believe someone over there can repair that head easy enough.

If the 470 was built originally with -13 heads, you should check how the valves interact with the valve pockets. The valves on -1's and -13 heads aren't in the same place......at least they aren't on a 440-1 and a 572-13.

It could limit how big of a cam you can fit in there.

Thanks i didn't know that. I approached a couple of people over here and they didn't want to know, shipping is around 50-60 dollars in english currency to US.
To be honest, I may move the indys on at some stage and either go back to my RPM'S or buy my friend's BS heads and sell the indy's and the RPM'S, then use the bigger roller.
Here's a couple of pics of the BS heads.

I've done a few sets of BS heads that ran pretty well, but they are pretty low in the pecking order of bb heads in terms of my preference.

I'm shocked its that cheap to ship heads back here. It costs that much to ship from where I am to the west coast.

It's maybe more like 70 to 80 dollars but it's only one head.
Surely the BS heads would make more power than my RPM's, after all they have a larger intake valve, smaller chamber and raised exhaust ports ?
Mick

They require offset intake rockers, and IMO just aren't good enough to justify the expense of that. Also, unless you have fender well headers, spark plug access is a pita.
There is no way I'd sell -1's I aready own and use BS heads instead....... But that's just me.

If what you want is non-raised std port heads that are an improvement over your RPM's, just sell what you have and get some TF heads.

The BS heads are junk. LOL. Here's a picture of my Friends Charger that has gone 8.60's with them

The BS heads are a really good price, they have 1.6 koffel roller rockers, shafts etc, new K motion springs, + he's only just had them ported last year. I wouldn't be interested If i had to buy them new but the guy has twice as much in them as he's asking. Would they fit with TTI headers ? bearing in mind my car has no inner fenders.

Hell, my motor would go 9 flat in that thing...............what`s it weigh?