[gtofreek]

Was wondering how much volume in cc's that a stock RAIV heads intake port holds? Thanks!

[Skip Fix]

I think the NHRA spec is 185cc. But that could be tweaked as the chmaber volumes were.

[Skip Fix]

http://www.nhra.net/tech_specs/runners/RunnerList.xls

[67GTO4SPEED]

182 - 183cc as cast, according to Pete McCarthy's Ultimate Head Test.

[steve25]

Which casting number 614, 722?
Does it have a date code,and if so was it cast after 1970?
Does the wing along the valve guide stop at the end of the valve guide, or does it boat tail out till near the seat area?

[Skip Fix]

My SR 614s have been pocket ported but I've never CC'd them.

[67GTO4SPEED]

Originally Posted by 67GTO4SPEED

182 - 183cc as cast, according to Pete McCarthy's Ultimate Head Test.

These numbers were quoted for the '69 722's. In those tests, the '70 614's outflowed the 722's, but he didn't list the intake cc volume on the 614's.

[gtofreek]

I ask because I'm helping a customer from Sweden with R&D of some stock and super stock heads for NHRA racing. These are Edelbrock BB Dodge heads. They come from Edelbrock at 210 CC intake runners and 70 CC exhaust ports. NHRA approved these heads, then 7 months later changed the rule, saying they have to be no larger than a stock iron head at 203 cc intake and 64 CC exhaust ports. We have tried everything to get these down to the legal spec and we are still 2 cc's too big on both. This is with minimal valve job and tulip valves also.

This is just ridiculous. NHRA won't budge and Edelbrock says, " hey, they approved it", so they won't budge. So I was wondering why it is that the NHRA legal head for Pontiac is a good 30 CC's bigger than the RAIV head it was designed after, and that is fine, but they won't allow this BB Dodge head at just 7 cc's bigger? One guy doing these heads in California figured the only way to get them legal was to cut the intake manifold surface back to the valve cover bolt holes[which NHRA allows], then cut a step so they could continue to cut the runners down to legal size. NHRA approved it. So we ask NHRA if we can cut a step to get it down to 203 and they say "No, the factory heads had no step". Seems these people just can't make up their minds. Makes no sense to me at all. The real kicker is, they stipulate stock runner cc size since it is a stock class, but yet they allow anything to be done with the cam as long as it has no more than .480 lift, and you can run headers too. Go Figure! Did you ever see a factory stock engine with a cam that had 268° @ .050"? Neither have I.

I wasn't sure how big the RAIV runner was, but I was pretty certain it wasn't 215 CC's.

Some rules are good, while others are just stupid!

[gtofreek]

Thanks for the responses!

[steve25]

Install a real long replacement valve guides that should get you there and this is a good area to not effect the flow much.
Its real important on those short exh runner Mopar heads that the outside circumference of the port at the flange be 1/16" smaller all around than the inlet of the header tube, this is the only way to pick up the 4% more high lift exh flow from the headers.
You may need to weld material back in to get it.

[gtofreek]

You cannot add or do any hand grinding on these stock class heads. That's the problem. They won't let us add anything to make the port smaller. Super Stock allows adding material and hand porting. Stock class, they just won't budge and inch.

[J.C.you]

Sometimes determination to run a particular head/ engine combo that does not fit into the existing rules becomes cost/time ineffective. Petition the nhra tech and they may come around at some point in time or go to another combo.

[gtofreek]

Originally Posted by J.C.you

Sometimes determination to run a particular head/ engine combo that does not fit into the existing rules becomes cost/time ineffective. Petition the nhra tech and they may come around at some point in time or go to another combo.

This guy already took a head to the NHRA techs at the race in Phoenix. They got all 7 techs on the phone and had a conference. 2 were for working with the guy, 5 were against it. It's just pure BS in my opinion, but then again, it is just my opinion. This guy is going to have more money in trying to make them legal, then in making them perform.

[Skip Fix]

Paul Scott Burton runs a 70 model in stock, John Schloe used to run them on his 69 before he hurt them. They might have some insight.

Also I thought the Eddy heads were just OK in SS. I do know they allow aftermarket blocks.

[gtofreek]

There's a guy doing these heads that are supposed to be legal, but the only way he could make them legal was to step the intake manifold surface. He sent pics to NHRA, they said, that's OK. Now they say that if they see a head with a step it will be disqualified. These guys can't make up their minds. It's ridiculous! There are 12 sets out there now at $4500 per set that may get disqualified now if they win a race.

[77 TRASHCAN]

Paul, Don Kennedy is a member here, might send him a PM, his 82 T/A that had the 455SD in it had modified ports. I remember him telling me about an engine miss he had, searched and searched....a piece of epoxy had broken loose and blocked an intake valve...

[Skip Fix]

Or buy Tom S's real RAIVs

[jm455ho]

I had a set of 70 RAIV heads that measured 193 cc's. I think you are confusing the rules between stock and super stock classes. You are not allowed to run the Edelbrock heads in stock class. They are approved for super stock, and can be ported, but must adhere to size limits.

[gtofreek]

These heads are approved for both stock and super stock. The size limit for both is 203cc intake, 64 cc ex. They come 210/70. The difference is in super stock, you can use epoxy, weld up the port, port them, do what ever you want to inside the port to get the volume down. That's not a problem. The problem is, in stock class, they won't let you use epoxy, or weld, or hand grind in the ports. everything must be done in the bowl with cutters, off of guide center. We've been over the rules on these. I did minimal valve job, just enough to seat a valve, no throating at all, and some were 212cc already. Sinking the valve some to get a better valve job, got them down 1 more cc. How in the heck are you supposed to get them down from 211-212 to 203 without being able to add filler. That's the problem. The super stock version, being able to port and add filler, flows 60 cfm more than these with stock class rules. Same head, both at 203 CC, 60 CFM difference just being able to fix the port.

We got them down to 204 cc's now. We have one more thing to try tomorrow to try to get to 203. Then, that's all we can do without ruining the valve job and hurting the flow.

The ex. is still 2 cc's too big. Not sure how we will get that one there, but we'll try something else tomorrow to see what that does.

I just don't understand how they allow Pontiac heads as much as 30 cc's bigger than stock, that flow considerably higher than these Dodge heads that are only 7-9 cc's bigger than stock, on both intake and exhaust. Don't get me wrong, I'm glad they allow the EDDY head for Pontiac's, I just don't know why they are picking on the Dodge boys so hard. They are the only ones they did this to. All this AFTER NHRA approved these heads originally at 210/70cc's. They changed the rule 7 month's later, to 203/64.

[steve25]

Paul, how many CID is this BB Mopar( 400 low deck, 440) and the guy tell you what the FPS is at peak flow right now?