dart 215 pro 1 platinum upgrade on 383 sbc

[Carnut1]

Sorry you think it was a jab but in the past I developed ports cut and try if you remember the "Two heads are better than one power porting the E7TE head" or similar title I did with DV the best I could muster on those heads in the past was 220 cfm and with some Pitot action and flowbench work they ended 238 cfm with a similar cc port. Thanks, Charlie

[groberts101]

What did the runner actually CC?
As a novice head porter I would stick to the basics of thinning the guide, slightly widen and massage the short turn as well as the push rod pinch. I feel the head is border lined on being to big for what your doing but I could be wrong.

If you can get a trim to fit intake gasket I would go that route as I would not want to bell mouth the entry to fit a shelf gasket only to have the port shrink to a small PRP, I would want to reduce cross section size change as much as possible, you can pick up good cfm with only a 5 to 7 cc change to the runner but you can also hurt the head by going crazy on it if you have no data to show power gains from porting.

We been agreeing far too much lately.. might have to start arguing with you pretty soon so people don't think we're the same guy with two different signins. Lol

Steve. Here's my advice. Be careful on how deep you go here. You obviously have all the tools needed for the task at hand but this rabbit hole is nearly bottomless as the learning curve is steeper than most regarding cylinder head design. For that reason I agree with Gary's comments above. This head will easily respond to basic port work as the bulk if the design work is already inherent to that casting. All just depends on how many late nights and lost racing time you can tolerate too.

Can you post more combo detail? Trans gearing, rear gear, tire specs/diameter, converter, launch rpm.. shifts, and rpm across the stripe?

Without the bigger picture on what the starting baseline is, aside from mph and et, I'd lean towards a little wider lsa as that bumpstick will likely be considerably more peaky and fall off up top a little quicker than your last bumpstick. Peak torque will surely go up but you may need to change gear and/or converter to get the most from it, imo.

Hard to exactly tell from the pics but that bottom cut looks wide as hell. I like anywhere between a 78-84 throat cut hand blended into the port to better grab the air and ease the turn over the bottom cut. Don't worry if that cut does'nt show up on the short side since it doesn't need to be fully symetrical in that area anyways. Widening the pinch to available cross section(about .030-.035" pr hole wall thickness is more than safe) wouldn't hurt the ssr apex approach speeds on this deal either. All I got for now.

PS. How are you measuring throat percentages? Seat id or od?

[steve316]

On the intake leave the angles; radius the exhaust.If you blend more than the bottom edge of the intake you will lose cfm. That is what I have found it; that is what you can check on your bench. Also try for constant port velocity. Good luck you will never learn younger.

[GARY C]

What did the runner actually CC?
As a novice head porter I would stick to the basics of thinning the guide, slightly widen and massage the short turn as well as the push rod pinch. I feel the head is border lined on being to big for what your doing but I could be wrong.

If you can get a trim to fit intake gasket I would go that route as I would not want to bell mouth the entry to fit a shelf gasket only to have the port shrink to a small PRP, I would want to reduce cross section size change as much as possible, you can pick up good cfm with only a 5 to 7 cc change to the runner but you can also hurt the head by going crazy on it if you have no data to show power gains from porting.

We been agreeing far too much lately.. might have to start arguing with you pretty soon so people don't think we're the same guy with two different signins. Lol

Steve. Here's my advice. Be careful on how deep you go here. You obviously have all the tools needed for the task at hand but this rabbit hole is nearly bottomless as the learning curve is steeper than most regarding cylinder head design. For that reason I agree with Gary's comments above. This head will easily respond to basic port work as the bulk if the design work is already inherent to that casting. All just depends on how many late nights and lost racing time you can tolerate too.

Can you post more combo detail? Trans gearing, rear gear, tire specs/diameter, converter, launch rpm.. shifts, and rpm across the stripe?

Without the bigger picture on what the starting baseline is, aside from mph and et, I'd lean towards a little wider lsa as that bumpstick will likely be considerably more peaky and fall off up top a little quicker than your last bumpstick. Peak torque will surely go up but you may need to change gear and/or converter to get the most from it, imo.

Hard to exactly tell from the pics but that bottom cut looks wide as hell. I like anywhere between a 78-84 throat cut hand blended into the port to better grab the air and ease the turn over the bottom cut. Don't worry if that cut does'nt show up on the short side since it doesn't need to be fully symetrical in that area anyways. Widening the pinch to available cross section(about .030-.035" pr hole wall thickness is more than safe) wouldn't hurt the ssr apex approach speeds on this deal either. All I got for now.

PS. How are you measuring throat percentages? Seat id or od?

I thought about buying some Whisky today to liven up the conversation on here but I am trying to be a good boy but I can promise that evil Gary would insist that we disagree.

Since I didn't invite Bookers to join in I have to agree that more rpm related detail will help with further recommendations.

[GARY C]

Finally you get it!

Funny, but I doubt it.

Are you guys really serious?!? LOL
I mean, tools and information are good, but PLENTY of great cylinder heads have been developed without the use of either.
I know you guys are strong proponents of such, but really?

BTW Carnut, you need to actually get something to run with success before you start throwing jabs, because all the stuff you have posted over the last year or two is all theory, and has yet to run on anything!
And while I'm at it, I don't think your floor is near wide enough to require that monster vane/fin, but that's just my opinion. It obviously doesn't count here in the midst of all these experts, but hey, it's a free country!

Nothing personal but your first statement is both historically and factually wrong.

I would however have to agree with your second one based on my limited testing.

[steve cowan]

wow,
thanks for all your input,i will give specs on combination first then try and answer questions,
early 010 block factory 4 bolt stud kit top and bottom
scat 3.75'' steel crank std
choice of scat 5.7'' i-beams 8740 bolt i have used these up till now and bearings look good.also have a set of 5.7''H-beam scat rods they are getting crack tested,resized and arp 2000 rod bolt upgrade.
moroso billet oilpump and 7 qrt kickout oil pan but i only use 5 qrt of oil and a long ryco z24 oil filter which i cut open after each meeting and inspect as required.
xledyne timing belt drive which is similar to a jesel the belt just come off was a tad loose but i have since aquired a tighter undersize belt,when i degree a cam it is with all engine assembled and i go 8 degrees either way to check piston to valve if i choose to change cam timing on the fly later on.
i have a choice of cams but was using comp billet N20 cam that i got done some years back
254 -260 @ 0.050''
lobes 4130/4149
680 lift with 1.6 rocker
112LSA in at 106ICL
cam card say ICL of 110 i did not try this
comp needle roller lifter to suit small base circle,i have used the needle roller lifters for some years and have not had a failure but i am very fussy to check lash all the time,i use the EX op IN cl method as i have found approx 0.004'' difference from the usual TDC method but thats just me.
i have a few different sets of 3/8 moly pushrods cv products at 0.120''wall
dart pro 1 as specified
jesel sportsman rocker system 1.6 intake and exhaust
msd billet distributor with slip collar and composite gear with good results
super victor intake untouched,choice of spacers and i found the blended 1 inch spacer seems to work well.
i have 3 carbs,
830 annular which i usually drive to the track and on the street keeps plugs nice and clean i have it tuned lean 15:1 air fuel at cruise
850 speed demon 1 3/4 throttle bore that i am trying on my 327 at the moment have not used this carb on the 383.
950 hp holley that i bolt on at the track,the car runs the quickest and fastest with this carb so far but i need more tune time on the PVRC as it is a bit to rich for me on the street,i dont like dirty engine oil due to fuel wash.
i use a meziere electric water pump amd thermo fans,160 amp mds alternator.
pipes are 1 3/4 primary approx 26'' long 3'' collector which is only 12'' long,i made a twin 3'' inch exhaust myself with aero chamber mufflers dumpers at the diff,there is no X pipe.
turbo 400 gear box reverse manual valve body,8 inch custom 5600rpm converter made by TCE here in australia,i also have a 9'' 4000rpm converter which i used inially when i got the car to the track with the bigger converter it picked up 3 tenths all in the 60ft.
the gearbox has big TCI pan and big cooler and the big converter drives well on the street,no problems at all.
3 1/2'' chrome molly tailshaft,billet yoke 1350 uni's
small bearing 9''
billet 31 spline axles
stange nodular centre
alloy pinion support
1350 billet yoke
4.1:1 small bearing gearset
trutrac locker
the car is a leafspring rear end i modified the leafs by drilling the ends and bolting and plating the leafs so they do not seperate on launch,caltracs are fitted and set to std specs on preload-plenty of work there to make this work correctly over time,koni adjustable shocks.
front end has koni adjustable shocks and swaybar,more work and testing there as well.
fuel system
60lt alloy fuel cell
-10 feed to 200 gph holley mechanical fuelpump
-8 from pump to QFT fuel log then holley return bypass reg after carb
-8 return to tank which is foam filled to stop froth
i rewired the car and have all autometer stuff and a msd programable box which i use a fair bit and like.
the car is able to run to 10.00 as per australian rules
there is a 4 point roll cage
4 point harness
car weight 3400 with me

[GARY C]

What rpm do you shift at and what rpm does it go through the lights?

[steve cowan]

charlie,
i have a sharp edge plate that was supplied with the bench,and i have pitots as well that were supplied with the bench,i want to make it clear that am still trying to work out the bench and the software,i do not have a valve opener but i can jury rig something to get me started,the intake is at 217cc i rechecked last night as per photos,i have not taken any radius into consideration here in my measurements,i measured the seat throat below the seat to come up with my %
i read every head porting thread and have been going back to early threads trying to learn the theory,i appriciate the effort everyone on speedtalk as it takes effort and time to do photos and uploads etc,i left the chamber as cast for the reason of not polishing,the chamber would not be optimised from the factory,as i have said the heads are as cast from dart and all i did was de-flash the casting a few years ago and my intention was to run as is and see where it takes me,now it is time to try and make some more power,i just basically bolted the engine together and thinking i will make 530 hp i was so wrong,this thread will run for some time as i try and find some answers i will post up where i am at,i have a cast dart 170cc head that i am will to sacrifice in the learning process,i dont want to become overwhelmed with the subject but i believe it is just that,

steve c

[steve cowan]

gary,
this might sound strange but it ran its quickest going to 7500 on the shift and traps 6800
a set of 4.3:1 would help it trap at 7000
i know that is some rpm but it responded and i dont have the answer,

[ozyfordman]

Steve,
This is a very interesting post. Can you share the details of your flow bench? Is this run on single phase power? I have a friend with a Superflow 300 and it occasionally trips the 32 amp breaker on full noise. This is on 3 phase. I have toyed with the idea of either buying ot building a bench. I even bought plans from Tractor Motorsport but the power supply has stopped me from progressing. I have a 6/71 blower and a 12 hp diesel engine I was going to use but this is a bit of a project. Any details on the bench you can share would be appreciated. I live in QLD Australia , so 240v ac single phase power is what I have available.
Using science to scope out you head development is the right way to go. Pipemax is awsome if you don`t have a copy, get one. Engine Anyliser Pro is also a great tool for playing around with to get you in the ball park. That ute must be thirsty driving to the track and back with that cam and gears. I like the idea of a car that does double duty like yours. Great stuff. Keep us all posted on your findings.
Evan

[GARY C]

gary,
this might sound strange but it ran its quickest going to 7500 on the shift and traps 6800
a set of 4.3:1 would help it trap at 7000
i know that is some rpm but it responded and i dont have the answer,

That was where my 72 Nova was on shift and trap in the 1/8 mile with a 4.88 and a 29.5 10.5 tire, it was a nitrous car so more gear was not an option due to wheelies, a reduced 1st gear in the power glide would have helped but I sold it before going that deep.

[steve cowan]

Steve,
This is a very interesting post. Can you share the details of your flow bench? Is this run on single phase power? I have a friend with a Superflow 300 and it occasionally trips the 32 amp breaker on full noise. This is on 3 phase. I have toyed with the idea of either buying ot building a bench. I even bought plans from Tractor Motorsport but the power supply has stopped me from progressing. I have a 6/71 blower and a 12 hp diesel engine I was going to use but this is a bit of a project. Any details on the bench you can share would be appreciated. I live in QLD Australia , so 240v ac single phase power is what I have available.
Using science to scope out you head development is the right way to go. Pipemax is awsome if you don`t have a copy, get one. Engine Anyliser Pro is also a great tool for playing around with to get you in the ball park. That ute must be thirsty driving to the track and back with that cam and gears. I like the idea of a car that does double duty like yours. Great stuff. Keep us all posted on your findings.
Evan

evan,
thanks for your response,flowbench manufacturing australia is who i purchased through last year,warren eames is the gentleman who owns the company and they offer a couple of different benches,there website is the place to look,
it is made to order and takes 4 weeks to build
i have the FME 400 P
10 amp single phase 240 outlet
400 cfm @ 28 inches
bench is supplied with laptop,calibration plate 365.4cfm @ 28 inches
intake and exhaust pitots
performance trends software port flow analyzer
user manual,software loaded
you need a aircompressor at 50 psi to keep flaps sealed on the bench during operation,warren is good to deal with and will help if you get stuck,it also comes with 2 x bore sleeves of your choice.
this bench cost me $8000 at the time
i am not sure what the smaller bench costs,yes a lot of money for someone at my level but i want to make a go at this horsepower thing but its a can of worms as i am finding out,like the saying goes if it was easy everyone could do it.
it cost me around $200 per day at the track without any dramas,i have been on the back of a tilttray a couple of times so far but thats the deal i spose,i am nearly at the point of a car trailer deal if i go a lower rear gear due to hwy rpm unless i do a gear vendor overdrive or a 4 speed auto,the drive can be a pain over that distance and time,thankfully have not been stuck in traffic jam as of yet.
i see alot of guys use pipemax and sounds like a great add on
i have engine pro that i play with every now and then,i just have to be careful with all this information available as i think it is easy to get lost at my level of thinking
hope all this helps evan talk soon

steve c

[Warp Speed]

Funny, but I doubt it.

Are you guys really serious?!? LOL
I mean, tools and information are good, but PLENTY of great cylinder heads have been developed without the use of either.
I know you guys are strong proponents of such, but really?

BTW Carnut, you need to actually get something to run with success before you start throwing jabs, because all the stuff you have posted over the last year or two is all theory, and has yet to run on anything!
And while I'm at it, I don't think your floor is near wide enough to require that monster vane/fin, but that's just my opinion. It obviously doesn't count here in the midst of all these experts, but hey, it's a free country!

Nothing personal but your first statement is both historically and factually wrong.

I would however have to agree with your second one based on my limited testing.

If your talking about cylinder heads being developed without a pitot and a calibration plate or?
If so, I stand by statement fully. Hell, I've witnessed the same being done and never ran across a flow bench! Lol
Or is it the part about Carnut needing run his stuff? Lol
Your "historically and factually" statement I'm confused about.......?

[groberts101]

If your talking about cylinder heads being developed without a pitot and a calibration plate or?
If so, I stand by statement fully. Hell, I've witnessed the same being done and never ran across a flow bench!

Though I don't want to trivialize some peoples time and development work on such things, much of which I have personally studied and copied whenever possible over the years,I too would have to fully agree with this.

Once you do even a half dozen sets of various cylinder head castings, and study the hundreds of others, shape and overall sizing in certain areas of the port becomes an obvious carryover. In fact, look at only one cylinders chambers and ports(ignoring symmetrical vs asymmetrical differing valve angles and whatnot) from various cylinder head mfgrs and it becomes quite obvious they can't possibly reinvent the wheel completely due to similar engine architectures used between them all. All these engines still get squashed under lower hoodlines and exhausts are forcibly bent and twisted under the car to make them fit in similar spaces. They all start to look the same and respond quite similarly after a while. Only way to move away from that is non-OEM designs which require custom manifolding and whatnot. Even then though same rules of physics still apply.. just don't need as many bandaids.

Sure there are tricks involved or weakness that present themselves when pushing far beyond any castings architecturally inherent design flaws or shortcomings to gain that last 5%.. but the first 95% of design and flow improvement is usually a direct carryover from most any other castings of similar design architecture. Valve jobs, bowls, and short turns and making sufficient cross section to prevent choking are where most of the gains come from.

IMO, if Steve wants to learn on these sets of heads then more power to him. But I myself would not start getting over the top on something which is already running decent and obviously very heavily invested in to begin with. Do the basics, maybe get a little fancy with port speed equalization since he has a flowbench pitot to check progress.. but learn and cut teeth harder on something else that isn't so important.

[GARY C]

Are you guys really serious?!? LOL
I mean, tools and information are good, but PLENTY of great cylinder heads have been developed without the use of either.
I know you guys are strong proponents of such, but really?

BTW Carnut, you need to actually get something to run with success before you start throwing jabs, because all the stuff you have posted over the last year or two is all theory, and has yet to run on anything!
And while I'm at it, I don't think your floor is near wide enough to require that monster vane/fin, but that's just my opinion. It obviously doesn't count here in the midst of all these experts, but hey, it's a free country!

Nothing personal but your first statement is both historically and factually wrong.

I would however have to agree with your second one based on my limited testing.

If your talking about cylinder heads being developed without a pitot and a calibration plate or?
If so, I stand by statement fully. Hell, I've witnessed the same being done and never ran across a flow bench! Lol
Or is it the part about Carnut needing run his stuff? Lol
Your "historically and factually" statement I'm confused about.......?

I remember Ferrari making the claim that they have moved beyond the flow bench because they were so technologically advanced and how they have moved beyond traditional cam development and grinders but they forgot to mention that all their programs were developed by farming out to head developers that use flow benches and cam designers that use traditional methods and grinders.

But even if they take that "information" to the next level via computer/advanced "tools" they still need "information" and "tools".

History documents the development that has brought us modern day information and it is factually impossible to develop anything without information and tools.