I went with a high rise dual plane (ported) instead of the single plane to maximize throtle responce and low end torque. Prior to ordering the heads, I informed AFR what intake I was using. They recommended the 210's (engine is a 406). I went to install the intake and set it on the gaskets. The bolt holes line up perfectly but the intake runners of the heads are too high. The intake manifold runners are approximately 1/8" too low. You can see the Printoseal which tells me the ports are way out of alignment.

I called AFR and they informed me that the 210's are designed to match the Vic JR's "tall" intake ports. The heads are not "raised runners" just taller medium race ports, not raised. I wish they would have told me this earlier.

Well anyway, I have some double thickness gaskets on the way hoping that they will raise the intake enough to get the ports to line up (the intake and heads are gasket matched to the 1206 gaskets AFR said to use, the heads took a whole 30 minutes to port). I'm not all that confident this will work though.

Is there anyone that has gone through this before? If so, what did you do?

I really don't want to run the Vic Jr or Super Vic because of hood clearance issues and the Torquer hasn't worked very well for me in the past. The engine will not see rpm's over 6500 either.

Any thoughts would be appreciated. Mike

 

I think the AFR 210's are kinda mismatched for a under 6500 dual planed motor. I think ya should make up your mind if you want a mild street motor or a fast one. Then either get smaller heads (AFR 190's maybe) or a single plane intake to match. There is a good reason they match the 210 heads to bigger intakes....they need it.

 

Well, according to Edelbrock, in stock unaltered form, the victor jr and the performer rpm have the same port size and locations. I have a set of brodix track 1s and I am using a performer rpm and there are some intake ports that do show the blue silicon. But considering that the intake ports on the track 1s (and the afr 210s) are sized for a 1206 gasket (and the biggest I have ever heard a victor jr or perfomrer rpm being taken to is a 1205, even the victor jr-cnc that summit sells is only matched to a 1205), I think it is the nature of the beast.

Look at the recent 400 tests in chevy hp. They used 200 and 210 cc dart heads with performer rpms and made 450+ hp with a flat tappet. But as far as hood clearance goes, the perfomer rpm is listed as being .070 inches taller (4.65) than the victor jr (4.58) in the 96 edelbock catalog.

One other little item, what AFR calls the "TALL" intake port, is something that is designed to match with their 195 or larger CC heads. Both the perfomrer rpm and the victor jr are considered in this class of intake port.

Yes, I am sure there is some hp to be had if the ports were perfectly matched but I think it will be somewhat difficult to accomplish (can you say extrude hone?) I don't think it comes down to just using a Victor Jr.


[This message has been edited by jcb999 (edited October 01, 2000).]

 

from what i've seen with the afr 210's it isn't exactly height, it's the size of the runner. the bottom isn't raised like a raised runner is. your going to need a large runner intake to match. just my opinion also. a less than 6500 rpm 406 really doesn't need that big a port head, but you have them now.

 

I had some similar feelings about 210+ cc heads on a 6000 rpm motor until I did some checking.

There is a book called Street/Strip SB chevy Cylinder Head flow numbers by Trey Musgrove. The book has head flow ratings on a number of SB heads. In the book there is a formula that came from a mechanical Engineer professor at Ohio State. The formula basically says that you need an average cross sectional area of 2.35 square inches of intake port to feed a 400 motor at 6500 rpm. The formula basically assumes that an engine will have the best shift point (not peak HP) at about 2500 rpm higher the peak rpm where peak torque occurs and a specific amount of intake area is needed to allow that spread of 2500 between the torque peak and shift point.

Trey gave me the specs of a 400 that had a Track 1 head ported to 2.3 square inches and 230 cc. It flowed 300 intake and 210 exhaust. The motor was an 11 to 1 flat top and had a victor jr with a custom designed solid roller (691 intake w/1.6 and 268 @ .050 - 602 exhaust w/1.6 and 268 @ 0.050). This car ran 10.98 at 124 mph with a 4.10 gear and was shifted at 6500 rpm

Data in the book also supports similar methodolgy in that a 400 that is shifted about 6200 or 6300 needs a good head. (280+ cfm and 200 cc)


[This message has been edited by jcb999 (edited October 02, 2000).]

 

Thanks for all the input.

The gaskets arived last night.

Unfortunately, the Fel-pro wern't stocked so I had to go with Mr Gasket .125" medium race ports (it's a personal thing, I just like Fel-pro). They are just a tad shorter than the 1206's, but I can fix that.

I played around with them last night and it looks like they're going to work just about perfectly. I doubt that I'll have to work the bolt holes over at all. I may have to shim the distributor, but I doubt it.

As far as the head size goes, the 210's are what AFR recommended. I called them up to order the 190's and was talked into the 210's. I'm glad they did too. After much research, (talking to others that have built 400's, Desktop Dyno results, and my own calculations) I have found that 400 CID enginges need the kind of flow the "medium" sized heads provide. I met a guy running a 406 with Dart 230 cc heads, 9.5 1 c/r, an Edelbrock performer RPM and 800 Holley HP. Sounds like a serious miss-match don't it? Well I'll tell ya, the word "lazy" never entered my mind when he took me for a blast down the road (engine is in a '69 Chevelle too).

The height between the JR and RPM is close, but we all know that the JR needs at least a 1" spacer to shine. That's why they created the Super Vic. I've seen too many dyno sheets before and after a spacer was installed to be convinced the JR should be run without one. I have also seen many dyno results from SBC's running a dual plane and building 550+ hp. If they are gasket matched, a little port work and polishing, they will support up to 6500 rpm with ease.

I'll see in about a week what hp/torque this little sucker puts out. I guess I'll find out then if I screwed up or not.

Mike

 

so, what cam are you using?

 

I ended up going with a the Crower 00403 hydraulic roller and 1.6 Comp magnum roller rockers. 226/236 @ .050", .552/.576, 114 LSA. The LSA is wider than I was looking for, but the Dyno software sure liked it so I decided to not have it ground with a tighter LSA. I'll play with the cam timing to see where the engine wants it durring the dyno pulls. The software likes it retarded 5*, but I installed it straight up for a base line pull.

I've also got the Crower 00404 and the Crane 296 standing by if the 00403 dosn't give me the numbers I'm looking for. The 404 #'s are 236/244, .579/.603, 114. The Crane #'s are 234/242, .574/.595, 112.

Depending on how well the day goes I might just run all three to see the different effects they make. The speed shop has a few single planes there that we can play with as well. $500 a day will defintely be a concideraion when making changes and pulls.

JCB, what timing curve did you end up with? How much total and at what rpm did you find your 400 liked best?

Mike

 

I am still tuning a bit but it really liked 15 inital (but is happy with a little as 13) and I have 22 in the distributor. I have not changed the curve but it is all in by about 2200. I am running a tighter lsa than you (which requires a little more intial timing for good vacuum) and at this time I am using about 30 percent race gas but I will be cutting back on that a little more over the next few tanks.

PS, if your car/engine combination is like mine, you will not be able to imagine what you would do if you had more power. My car revs so quick that you need to start thinking about changing gears about the time the accelerator hits the floor. My engine makes so much torque, I have no reason to spin it to much over 6000.

[This message has been edited by jcb999 (edited October 02, 2000).]