Dart 180 cc alloy head as cast

[steve cowan]

surprising how many people don't understand the machine they are using or own.

Stuska doesn't have a interia factor as a entered number.

Ok. dont take this as anything but constructive it just proves my point and shows there are many in the dark.///A stuska has to have an inertia factor entered or else its been hybridized, converted, has different acquisition...///or its no longer a stuska dyno////this is not to say that continually changing it for different platforms is required or necessary for development.///repeatability=internal development///
Its entirely possible the dyno owner has never touched its initial setting or knows of it////not uncommon//the problem comes from the this dyno reads low crowd///and like I say they all do read low just ask the owner of one If everyone was on top of the workings of their dyno/regional comparisons can become much more meaningful//I have witnessed very good consistency from one dyno to the next myself///but it takes knowing and staying on top of things along with having a dyno owner that doesn't have too much ego to admit he don't know why some things are the way they are///bottom line..a stuska dyno is extemely intertia factor dependent.

The dynos at EMC did however, which were DTS.

Last i looked dts was using a bit of inertia factor input into their correction math////very small component compared to stuska///small enough that at a dyno contest like enc i foresee there would be more inaccuracy and conflict amongst competitiors by changing it than if left alone///back to the point of a engine dyno contest////everyone dynos on the same dyno///everyone knows the rules going in///build an engine friendly to that small amount of inertia factor input..its very small///i would bet the teams that do well at those events know some things about how a dyno works////watch and listen to some videos on engines making pulls on dts, superflow, stuska///you can generally hear why a stuska needs inertia applied//almost my bedtime and i missed wheel of fortune

Elroy,
thanks for the contribution
i think everyone can learn something from that post

[zums]

I would spend some time on the vic jr on the bench with a probe, no sense sinking tons of time in the heads without sorting the vic, get your csas in shape, i dont see why 245-255 through the induction wont get you where you want to be
Tom

[SpeierRacingHeads]

Can anyone post a link to any major engine builder doing a 383/550hp crate engine?

[PRH]

Can anyone post a link to any major engine builder doing a 383/550hp crate engine?

Seems like the cubes sell....... and since a 427 isn’t really anymore expensive to build from all new parts than a 383........ it doesn’t seem like many people are building higher effort 383 crate motors.

402”, 10:1, hyd roller, unported heads, RPM intake:
https://www.shafiroff.com/chevy-pump-ga ... street.php

[SpeierRacingHeads]

Can anyone post a link to any major engine builder doing a 383/550hp crate engine?

Seems like the cubes sell....... and since a 427 isn’t really anymore expensive to build from all new parts than a 383........ it doesn’t seem like many people are building higher effort 383 crate motors.

Not sure some think it's a "higher effort" build??

I get the impression the as-cast 180 should make that.

[PRH]

Here’s one...... 383, 537hp...... uses AFR 195’s:
https://westcoastengines.com/383-stroker/525-hp/

Here’s another one...... uses AFR 210’s:
http://www.whiteperformance.com/engine_ ... 562hp.html

My point was, it’s not hard to find pretty mild street 383’s....... like a GM ZZ build or equivalent.
The 550hp pump gas builds just seem to usually end up being built from more cubes.

[SpeierRacingHeads]

Here’s one...... 383, 537hp...... uses AFR 195’s:
https://westcoastengines.com/383-stroker/525-hp/

Here’s another one...... uses AFR 210’s:
http://www.whiteperformance.com/engine_ ... 562hp.html

My point was, it’s not hard to find pretty mild street 383’s....... like a GM ZZ build or equivalent.
The 550hp pump gas builds just seem to usually end up being built from more cubes.

All much larger than 180cc and both far from as-cast.

That was my point. It's going to take some cylinder head to make 550hp from a 383 SBC.

[PRH]

I agree.

I’d think something flowing a solid 275-ish in the 200cc range would get it done.

[SpeierRacingHeads]

I agree.

I’d think something flowing a solid 275-ish in the 200cc range would get it done.

Yes, I agree..

We did one that made 550 on pump gas, but needed a solid roller to get it done.

Vacuum pump would have helped. 10-1 compression

Import head that flowed 270 through manifold/carb.

[PRH]

“Needed a solid roller cam”??
As in...... you started out with something different, and couldn’t reach your goals with it, and then swapped to a solid roller??

Or..... you just started out with the solid roller in the first place??

[SpeierRacingHeads]

“Needed a solid roller cam”??
As in...... you started out with something different, and couldn’t reach your goals with it, and then swapped to a solid roller??

Or..... you just started out with the solid roller in the first place??

Started out with a roller, just like I did but mine was much smaller.

IMO, HYD rollers suck.

[steve cowan]

I would spend some time on the vic jr on the bench with a probe, no sense sinking tons of time in the heads without sorting the vic, get your csas in shape, i dont see why 245-255 through the induction wont get you where you want to be
Tom

Hi Tom,
Good to hear from you
I have a new Holley strip dominator intake as well I want to look at, seems like a better fitting intake compared to the victor. I had a dream of testing 2 different intakes at the dyno but I doubt it would happen lol

[steve cowan]

So the discussion has been great, thank you to all involved.
Want to be clear -
There are a few guys on the forum that can make great power with as cast heads, I am NOT one of them
Back to tech
This is my plan so far
11.5 :1 comp
MS 109 or sunoco 260 at the track
Pump 98 on the street
Low tension oil ring and vac pump
5.7"rod
Cylinder head
2.3" at the pinch ( already done)
2.02"valve @ 89% 2.52"CSA
2.4" average CSA
Once it is all said and done the head will be 200-205 cc
If I can get close to the cfm/ sq inch at the throat, pinch, valve etc
I would think the result would be approx 290-295 cfm
As far as cam goes
Intake around 240degrees at 0.050"
With a closing point of 45degrees
Exhaust I would think more duration and an exhaust opening of approx 55-60 degrees at 0.050"
This makes the Howard's roller a bit small on the exhaust side and I think 0.600" plus lift would make alot more sense.
I have another Howard's roller
257-263 @ 0.050"
680" lift with 1.6 rocker
106LSA 4 degrees advance ground
4/7 swap
But I think this cam might be to big on intake duration.

[CGT]

MS 109

Neat fuel, but expensive.

Low tension oil ring and vac pump

I would suggest making some pulls each way. There is usually always something to learn for future builds by doing so.

With a closing point of 45degrees

IVC of 45° is pretty close for a 6500rpm 383 in my opinion, give or take depending on some things.

Exhaust I would think more duration and an exhaust opening of approx 55-60 degrees at 0.050"

I agree on the more duration. I think a 60° or even earlier EVO would help the top without hurting the bottom...once again depending on some things Low 240's intake high 250's exhaust 110 lsa would be about where I'd be on it.

[paulzig]

IVC of 45° is pretty close for a 6500rpm 383 in my opinion, give or take depending on some things.


I agree on the more duration. I think a 60° or even earlier EVO would help the top without hurting the bottom...once again depending on some things Low 240's intake high 250's exhaust 110 lsa would be about where I'd be on it.

238IN 254EX on 110 with 4 degrees advance would get you the 45IVC and a 61EVO... Might get some odd looks on the 16 IN/EX split though You could do a lovely hydraulic roller with lobes like that...