351 C valve seat and diameter question

[hotrodford]

I have used the factory stock intake and out of curiosity and a recommendation from Randy Gillis, RIP, I put an Edelbrock #7129 on it (it was less than $200 when I bought it).  Even though the 7129 is designed for the 2V port location with the track and competition as my dyno it has been the best $200 I have spent!!!!   Dennis

[Falcon67]

The port match isn't real good LOL but it is a good trick.  I've run a 2V Funnelweb on my 4V when I didn't have anything else available and it worked well enough.  I'd still encourage you to consider the port tongues if rules allow - you'd certainly pick up torque coming out of corners and that should reduce your lap times.  Port work - I did mime in the shoip  - is really minimal on 4V heads.  The final numbers IIRC were 330~340 at .550 intake and right at 200 exhaust at same height.  I run a solid roller 248/254 with .664/670 lift - custom Lykins Motorsports cam.  Drag racing, so the only corner I turn it to gently exit the strip.  If you update your cam, I very much encourage you to discuss your needs with Brent at Lykins - he can get you a stick that works.

A view of my filled intake ports - updating the engine after lunching an oil pump, should be back in the car shortly.  Dufus here misplaced a pushrod so waiting on one stinkin' 8.250 x 3/8 pushrod to come from Summit [facepalm]

[hotrodford]

I appreciate all of the input.

Are those Price Motorsports Stuffers you have there?

Since I have to get the car together and ready to race for May, for now, I will "mildly" work on the short turn and increase valve size only enough to gain a more favorable entry from the bowl area into the combustion chamber. 

Thought I would use a cartridge roll on the short turn just enough to take that "high spot" off, so to speak, as shown on the pic attached. 
Dennis

[Falcon67]

My stuffers actually came from Parker in Australia.  If PME makes some, those would also work.  Yes, just a bit of cleanup to smooth the air flow could help.  It's a big port, no need to get crazy LOL.  Finally found some pics stored on my web site

[kcoffield]

....My stuffers actually came from Parker in Australia.

Chris, did you install them pretty much as is? It's been a long time, but I thought the Terry Parker stuffers also crept up the side of the port so as to bias the port toward the unshrowded side of the valve. Maybe that was just his "2V Funnel Web" stuffers? Ever try a filled floor intake or just smaller cross section intake on your C without stuffing the head port?

I ask because over the years, I've seen a number of B302 and 351C builds that have used intakes with much smaller (than 4V) ports that were not port matched and they made better power everywhere. They weren't really racing engines but fairly potent pump gas street car builds. One was a 347CI B302 headed engine with an Eddy air gap "e-Boss" dual plane on essentially stock B302 heads. Since the Eddy-made 335 series style head port windows are quite a bit smaller than the original B302, so is the Eddy intake. The ports were left unmatched on that stroker and it made ~530hp at ~7krpm and drove quite well.

I've been making custom cast intakes for a while now, and I've been making just about all of the 335 series lids with the runner floor raised 1/2" and telling the customers not to bother with the head port or trying to port match. This reduces the 4V cross section about 20%. The combination of the velocity increase and likely the port step being disruptive to low/mid reversion from healthier cams seems to get both good performance and better street manners. Some customers just ca'nt get past the idea everything needs to be perfectly gasket port matched and insist on the full 4V port......which they can have but wont run nearly as well.

It's also a popular misconception that 2V 335 series heads/intakes are just smaller cross section ports centered in the 4V pattern, but they are not, and are actually biased to the side and top of the 4V port. A quick look at a couple overlayed gaskets tells the tale. For quite a while, it was common knowledge in the Pantera crowd that the stock 351C would runner better at every rpm and especially down low just by bolting on a Weiand 2V "Excelerator" intake.

Best,
Kelly

[Falcon67]

Sorry, didn't see the q until now!

The stuffers are as-delivered, set in place with Splash Zone Compound and a 10-24 socket head cap screw under to hold in place.  I have seen pictures the ones that bias flow but have not noted that they come from Terry.  As for intakes, I have both a 4V Funnelweb (real, imported from AUS) and a CHI intake and those both fit the stuffed 4V heads and match well with my AFD 3V aluminum heads.  I have a 351C tunnel ram that I've had on the motor but a bit with a couple of "1850" Holleys for fun but never really worked them hard.  The mis-match didn't seem to cause any kind of trouble. If I get serious with the T-ram, I would look for something to fill the bottom of the parts at least an inch or so up to mate better with any heads.  Normal bracket config on the 351C is a 650DP on the Funnelweb. I will be trying methanol - again - this season on the 351C with a custom built 750DP.  A long term wish is the T-Ram with dual Holley EFI units on the 427 9.2 deck Dart build running both a gas and methanol program. 

I have run a 2V funnelweb on the 4V heads with the poor mis-match.  Ran well enough in that condition and it was all I had because the 4V was on the wife engine.  You are also correct, the 2V ports are not even the same.  An intake port will land as you said and in the 2V heads  the floor is way flatter and the short turn abrupt.  Velocity and flow is good, to a point. I have also done the Xcelerator 2V trick LOL.  When people start that "4V port just too big, terrible blah, blah" I just tell them "it's all in the parts combination and the tune up."

I'm running brackets, not Pro Stock so my attitude on port matching is

[kcoffield]

....When people start that "4V port just too big, terrible blah, blah" I just tell them "it's all in the parts combination and the tune up."

Truth.....light and even no work on 4V heads can still get good performance compared to other OE stuff, but something motivated you to stuff the ports. 

.....A long term wish is the T-Ram with dual Holley EFI units on the 427 9.2 deck Dart build running both a gas and methanol program.

I have a 427CI (4.125b x 4s) 9.5 deck Siamese Dart block I pulled from my Pantera. Also wearing Brodix BF301 think C302B) heads. Drop me a PM if interested in more details.

Best,
Kelly

[kcoffield]

....When people start that "4V port just too big, terrible blah, blah" I just tell them "it's all in the parts combination and the tune up."

Truth.....light and even no work on 4V heads can still get good performance compared to other OE stuff, but something motivated you to stuff the ports. 

.....A long term wish is the T-Ram with dual Holley EFI units on the 427 9.2 deck Dart build running both a gas and methanol program.

I have a 427CI (4.125b x 4s) 9.5 deck Siamese Dart block I pulled from my Pantera. Complete very low mile engine wearing Brodix BF301 (think C302B) heads. Drop me a PM if interested in more details.

Best,
Kelly

[hotrodford]

Are you all familiar with the D3 C head?  Reason I ask is because I have a pair that have been sitting in the corner for 30 years, so to speak, that I have never given a second thought to because they are open chamber.  For some reason I decided to take a closer look at them and, to my surprise, they have 2V valves but they are 4V heads. The "bowl area" is smaller as compared to the close chamber 4V head but is still an "inverted funnel" shape like other C heads. 

The inverted funnel shape of the bowl area, on C heads, puts the "throat" at the base of the short turn as opposed to right above the valve seat.  With the D3 head having a smaller bowl that translates into having more to work with meaning with a 2.1 valve or certainly a 2.19 the throat could be located right above the valve seat as opposed to 1/2" above the valve seat.

Would that translate into improved flow as compared to 4V heads that are 2.19 valve sizes OEM?

[Falcon67]

I took a set of 2V D1 heads and put 2.19/1.71 valves in them.  Did some porting, smoothing, etc.  At about .450 lift on the flow bench, the air quit making the short turn with a BANG and flow dropped like 30 cfm.  Still ended up in the 250 range at .550 on intake but it was weird.  D3~D5 cast "4V" heads all came with open chambers and  the 2V 2.04/1.66 valve sizes.  Most of those heads are D5 castings AFAIK.  If that short turn is close to the valve, IMHO as a total amateur porter I think you'd possibly aggravate an already iffy flow condition by increasing the valve size. The tongues raise the floor and give the air a better shot at the valve which would make the port work better for the larger valve area. 

[pbf777]

If that short turn is close to the valve, IMHO as a total amateur porter I think you'd possibly aggravate an already iffy flow condition by increasing the valve size.

     If 'just' increasing the valve diameter and incorporating a machine throat opening below the seat angles into the casting, then generally yes.  But again generally if one is incurring the effort to increase the valve size and this is with performance in mind some sum of porting/blending is involved which mitigates the negative, with the limitation then becoming based on the effort and capability of the individual, and/or the castings' capacity.   

The tongues raise the floor and give the air a better shot at the valve which would make the port work better for the larger valve area.

      Well, maybe; and it all sounds good, but it just doesn't always work that way.  Remember, the goal in port modification is to provide a greater effect of coercing vs. forcing the air to follow the path set forth by the port pathway, and sometimes this requires an influence upon the air column ahead of the the intended action so as not to grossly upset the continuity in that column in the greater ulltimate intent.

      As an example, though somewhat removed, and yes there are many influences at work, but just for thought:  For the most part, in time, a winding river will generally increase the arc of of it's turns, the river moving outward and exaggerating the radiuses (O.K. radii  ; and so remember one doesn't want to purchase the property "on the river" on the outside of a turn!  ); and haven't you always been taught that "water will follow in the path of least resistance"?   

      Scott.

[hotrodford]

This is a picture of the B302 TA combustion chamber.  This type of multiangle radiused valve seat isn't achievable on the production B302/Cleveland head, from what I am seeing, except maybe the D3 head. 

I have found some approximately 20 year old posts (other forums) that the D3 head is the head of choice if "one knows what to do with it"! 

What I am curious of is this type of radiused valve seat worth the work as compared to what can be done with the 2.19 valve heads? 

[pbf777]

This is a picture of the B302 TA combustion chamber.  This type of multiangle radiused valve seat isn't achievable on the production B302/Cleveland head, from what I am seeing,................

What I am curious of is this type of radiused valve seat worth the work as compared to what can be done with the 2.19 valve heads?

     Specific seat and adjoining contour angles and widths, in seeking something of ideal in greater flow, will vary by cylinder head type example, and it can be quite enlightening as to how sensitive some types are to changes; so one blanket statement could be dangerous territory, but generally the more gradual the transition the 'more likely' one will experience better results.  But there is also a limit to everything.   

     Scott.