NJLT1SS

In my quest for a cam and cylinder head package, i came accross these offering from Scoggin Dickey. If you look up LT4 heads on their website, it says that they offer them CNC'd, and to call for details. So, I gave them a call and spoke to one of their tech guys. They wont tell me who they send the heads to for the CNC work, but these are the numbers on them. they were flowed on a SuperFlow 1020 bench, with a 4.030 bore plate. The intake runners measure 206 CC, with 62 CC chambers.

lift intake exhaust

200 138 117

300 198 161

400 240 188

500 267 205

550 273 210

600 275 214

I was told that there are a few of these heads out there on some 383's that they have built, and have had great results with them. I personally dont know anyone that has used them, or have heard anyone on this board that has. If anyone can shed some light on them, that would be really appreciated, as I am still keeping my options open for a head and cam combo. If anyone cares to give them a call to ask them anything, they are part number SD3287, and hey run for $2165. This isnt a bad price considering LPE sells the same thing for $2895! The Scoggin Dickey heads come with LT4 valves(2.00/1.55), springs locks andd retainers.


Nick

NightTrain66

pretty good #s, If the runner volume is correct (205 cc) than it really needs to be on a 383 or a SERIOUS or S/C 350/355. It may not be correct.

Has anyone flowed this head or cc'd it to confirm these #s?

If the runner IS that big than the AFR would be a better choice IMO.

The AFR or this 205 cc LT4 head is bigger than the average LT1 buildup would require but a SERIOUS motor or future plans could require this size runner.

NightTrain66

Z28_LT4

I have a set of they're first heads they done and they looked like total crap when I got them. The CNC program they used didn't touch everything. There was cast surface left where the cnc didn't touch in the intake runner and inside the combustion area.

I called them to see why they look like that, and I was told that it was normal I decided their "normal" wasn't good enough and called them too see if they would cut me a deal on having them polished. They charged me 300 bux to port match the intake and smooth up the heads. That wasn't the greatest deal but I tried it.

My motor seems to run very strong but the engine is brand new top to bottom. I bought a new short block from Sallee Chevrolet and I have every bolt on I know of. It runs so good that my tranny broke first time out on the road. I don't have any track or dyno numbers yet, but I will when I find some time to rebuild my tranny.

here are the actual flow numbers before I had them polished. Not bad but not what they claim.

lift intake exhaust
.100 68 52
.200 131 113
.300 185 144
.400 235 175
.500 262 180
.600 264 184

Hope that helps. If you buy these heads I suggest buying the GM 847 cam

NightTrain66

with seeing the actual flow #s and hearing they are not gasket matched and cnc cutters do not touch everywhere, I do not think the port is 205cc as stated. I am assuming the LT4 acually ccs at 185 or so. After removing 20 cc'c from a port that flows 240 to begin with the #s "SHOULD" be better than those. I do not think it would take much material removed to be at those #s. The port hopefully is smaller than 205cc.

NightTrain66

Mindgame

Only port the part that needs porting. That's what many CNC programs do. So, if a port is cast close to final (after porting) size, you won't get any cleanup along the floor. Why increase the port vol by porting areas that don't need porting?
Really the only time you're going to see toolmarks throughout the port is when the head was cast small and opened up to something a bit larger, say 190cc to 248cc (like a set of SB2's -which by the way, I still have a set for sale-).
And, I don't believe 205ccs is large for a 350 pushing out in the neighborhood of 400 crank hp or better. For comparison, the LS1 head is about 205ccs as cast.

I agree with NightTrain though, the AFR is going to be a better head, even at the same port volume. Alot of that volume (AFR head) is in the bowl area. Not to mention, the exhaust port on the AFR's is really nice. Your choice.

-Mindgame

Soma07

FWIW stock LT4 intake ports are 195cc so 205cc after porting sounds fairly reasonable to me.

Ai

Hey.. they arent BAD, but its the general public's fault that they arent as good as they could be.... They sell them as machined. Why? Because people think it's pretty & would rather see machining marks than to have someone properly polish them out. Moreover, people equate CNC with something magical... it isnt anything special, we do it to save ourselves time and money. A cnc port isnt going to perform as well as a good hand port, b/c the master ports have to be conservative to take into account core shift. If we want more out of our CNC stuff, we have to go back and put a few hours into more porting.

I don't think their numbers are bad, but I'd like to see around 265 on an LT1 casting & a lil more on a CNC lt4. The reason they didnt flow what they claimed is probably b/c the masterports usually have a killer polish job for digitizing.

As far as not touching all the surfaces... what Mindgame said.. it's actually a good thing. If theyre $2200 that isnt bad, but if theyre $2200+core I'd go elsewhere & get another 30cfm out of them .

Flyin t/a

I think youd be best buying some stock lt4 heads and having someone do a mild port on them. It'll probably cost less and flow better. 265 is a good flow number but the lt4 heads flow 235-240 stock so they probably don't do that great of a port job or so it seems.

Mindgame

The point of CNC is not to make 'pretty' ports but to make consistent ports... each port a mirror of the next. I respect in the highest a good porter's ability but I can't see how you could possibly come close to creating consistency within hundredths of an inch like that which can be done with CNC. Consistency is not as big a deal with air only heads but when you start flowing fuel and air (carbed etc) it's even more important.
Touch-up yes, but initial port, no way. Of course the master has to be good... but that goes without saying.

-Mindgame

Ai

IMO, consistency is just the benifit, not the reason we do it.. $ is why we do it.

As far as handported vs. cnc... our handported stuff generally flows as consistently as CNC.. no joke. What miniscule variances there may be, are negligible IMO. All of the sb2's, yates stuff, etc. that goes on 2hp/cid + $50,000+ race engines have heads that are handported on them. They may start out a GPtech cnc or something if time is short, but they're still reshaped, and b/c we literally spend the time to measure everything... theyre alot closer to having the same dimensions than you'd think . That's the biggest difference between our stuff & other stuff, we don't do the whole by looks thing.

Mindgame

Well Phil, Kenny Weld would disagree with you on the consistency point. He spoke on the subject at some length last year. Flow is only one aspect of performance, uniform velocity is another... and it's just as important if not more so... at least according to Kenny Weld it is. Mike Chapman says the same thing.... of course you could always say, Well that's because they're selling CNC heads but I don't think that's it. What I know of the really top $ stuff is based on my relationship with Albert Wes at Speedway Engine Development, who happens to be a pretty good friend of mine. Don't know what you know of the Aurora race engine but SED was one of a few independents who worked on the IRL Aurora project. Now, that 'race engine' was very limited production and they could have very easily hand ported the heads but they didn't... they developed a port and CNCed it.... according to Albert, it was all in the name of consistency. The only hand work was the throat to seat blending.
So we can argue the point around, but I think that your velocity probing would show alot more than your flow numbers. Just my opinion on the matter. Maybe Chuck will chime in.

-Mindgame

Ai

My point was that... a human makes a master port to be digitized. Well, all of our handported stuff is similar to that, b/c each and every port is measured so theyre consistent. You can CNC to reproduce a human's best work, or you can spend the time to measure by hand & reproduce it. 99% of the time, variances a human cannot prevent arent going to matter IMO. As far as who we work with... can't say... couple different shops at present moment & the stuff is floating around the major race series, generally at the front of the pack.. but aside from that.. cant give specifics at this point. Doesnt matter.. we're talking a $2k street head, not a $12k race setup. Most people just wont spend the time to make ports as consistent as we do... on the stuff that takes forever, we do go ahead & CNC alot of it... but it's still all finished by hand.

Still.. irrelevant for these guys IMO.

NJLT1SS

Hey guys, this thread is turing out better than I thought, LOTS of great information! OK, just to let everyone know, the flow numbers I posted are from the SECOND design of CNC porting, which the tech guy told me is greatly improved over their first. The first design flow numbers are similar to what LT4_Z28 has posted. The do come CNC'd, but are not hand finished. That is a $300 option to have that done. The price of $2200 for them is outright, not with cores. I think for a total price of $2500 with hand finishing, you are at the range of a set of AFR 195 LT4's with their competition CNC port job. And as far as I have heard, the AFR's have some stellar flow numbers with their recently improved program. At that price, I might be tempted to go with AFR's. Does anyone have any flow numbers or stats on AFR's? The information on their website is not updated to reflect their new numbers.
Also, while we are on the subject of intake runner volume, I dont see how 206 CC would be to large for a 350. The hot ticket from GM Performance Parts, as an upgrade to their ZZ4 crate engine, is the Fast Burn aluminum cylinder head, which has a 210 CC intake runner. This is supposed to provide a 30HP increase over the L98 heads that come on the ZZ4, and still produce "tire shredding torque" as thier website states. If they would offer these in a LT1/4 version, I would be all over them. Some great info guys, lets keep this one rolling, thanks.



Nick

NightTrain66

I have always felt that a 400 HP 350 could use a 195-210 cc runner as well but for what ever reason I have seen LT1 heads ported as large as possible (280 cfm-185 cc I guess???) pull from 2000-6500 in a F-body with 6 speed and cc306. I have also seen LT4 heads with descent amount of porting (295 cfm-200cc runner??) with same set up be sluggish below 3000 rpm and make about the same power up top. Shortsides were widened a lil but not layed back or shortened much at all.

As far as making more HP at 6000 rpm on a 355 it might (should) do it but as far as comparing drivability to a head with similar flow #s but 10-15 (or more) cc's smaller then the acceleration or low speed torque should be better with smaller head. If ya would rather have the extra 10-15 HP at 6500 rpm and do not mind losing a lil torque down low the larger head is fine.
If a smaller cam was used with the larger volume head that could fix this problem and give some low end power back with out sacrificing much up top. Maybe the cc306 cam is a lil too large but due to the smaller runner of the LT1 casting it still pulls good down low? Not sure but these results I have mentioned are the same results i have heard from other people going from LT1 to LT4 ported heads. Unported LT4s seem fine but with much porting most people claim they are lazy. As I mentioned before, the one set I know of first hand had maybe 10 cc's removed and nothing to speak of from shortside and these are the results.

NightTrain66

Wild1

So what you're saying is a polished head is better with a hand job than a machine. Couldn't resist guys...