I was toying with the notion of going with vortec's and I am not totally against it.

However, I stumbled upon a set of Dart Pro 1 Aluminum heads for a reasonable price.

They are the 215cc intake runners and I was looking at a set of 180 or 195's before. Is 215cc to much for this motor combination:

92 350 block - .030" over
LT4 Hot Cam w/1.6 roller rockers and matching springs
Edelbrock high flo baseplate
SLP runners
AFPR
52mm throttle body
24lb injectors (might be going up to 30lb)
Ported 083 heads w/ 2.02/1.60 valves
Hedmann Headers & y-pipe
Catco converter
3" Flowmaster cat-back

Primary use for this car will be street with a few trips to the track.

 

Honestly,I love those heads,but they really will hurt you for a mostly street car.They like cubic inches and compression,along with a healthy cam profile.

I hate to say pass on a good deal,but I would on this one,and go for a set of the improved bowtie vortec heads,they look like the hot ticket for a street/strip car,IMHO.

 

I have my eye on those bow tie heads. Especially for the price. If I locate a good price on a tpi vortec base that is the way i am going to go.

How about the Dart Platinum Iron Eagles in 180?

 

Find a head that has intake ports with the same cross sectional dementions (cross sectional area) as your SLP runners and base manifold.

 

IMO, {within reason}, there is no such thing as
too big , except for paying for something that does not help.

It does not matter if the straight part of
the cyl-head inlet has a slightly larger cross-section
than the manifold, as long as transitions are reasonable
and ports match up.

It hurts a lot if the cross-section is too small.


naturaly, the cyl-head vendors do not
tell the mushrooms {aka customers} about
cross section area

 

[QUOTE]Originally posted by contact
[B]IMO, {within reason}, there is no such thing as
too big , except for paying for something that does not help.

It does not matter if the straight part of
the cyl-head inlet has a slightly larger cross-section
than the manifold, as long as transitions are reasonable
and ports match up.

I would have to disagree. The TPI motor is mostly based upon port velocityand this is what generates all the torque your TPI motor is famous for. The larger the runners the slower your port velocity will be. Unless your running more cubic inch and something different than a TPI type intake your going to knock the wind out of any bottom end power your motor might make. I think your headed in the right direction with your current specs. Has anyone found a good supplier for the bowtie vortecs at a decent price?

 

Thanks for your input. I am looking into a set of 180's right now or back on my original path of the Vortec's.

 

If you can get a good deal on the Dart Pro-1's then get them!

The port volume is not a showstopper at all. Take them to a competent head porter and have the floors of the ports epoxied. You get the advantage of port velocity, heat insulation, and a better shaped short side radius in the process.
It's a win/win situation.

 

Why would you buy a expensive head with a too big port
and then take it to an expensive head porter to muck it up with epoxy. ? Buy the right head in the first place.
There are many 165-180cc heads on the market that fit the bill. Your stock TPI head can be ported to flow more than enough air, for a lot less than monkeying up a large port head just cause it appears to be a deal. the Corvette aluminum L-98 ZZ4 head with porting is another good choice.
if you want to start with a Dart head get a 165cc Dart SS and port it. They port up beauti and you'll have a small port with plenty of velocity and flow.

If you were building a EFI motor based on the LT1 or Mini Ram short runner manifold I'd say go with the 200-215cc port. But for A TPI stick with a sub 180cc head.
I does make a difference. ( Average torque output)

 

200+ is too big. You'll lose velocity, power and they're too big to work with that cam. Mince cc'd at 198, flowed 280 and make power to 6300.

Save the big runners for 240*@.050"+ cams with single plane intakes.

 

I just measure the intake ports on my Edelbrock TPI baseplate. They measure approx. 1.70 x 1.23.

The heads I have looked into are all cast due to the amount of money I have to play with.

The Vortec's (which would need a different TPI base and more $) flow 224 @ .500" on the intake and 148 @.500" on the exhaust. These would require bigger valve springs and a little work to run a cam with a .525 max. The cylinder head company I deal with will get me the 906's with screw in studs and guides and the comp 987-16 springs all done to my door at $550 ready to handle this cam. Its not bad, but then I am spending $400 on the intake to run the TPI vortec setup.

The other head I looked into was:

The Dart Platinum Iron Eagles flow 222 @ .500" and 175 @ .500" on the exhaust. The intake port diameter is 1.910" x 1.120". These heads come with the 987-16 springs ready to handle .600" lift. These are going to run me around $800 to my door.

I would like to stay in the $800 - $900 range if possible. I am just thinking later on if I want to alter this setup again I would prefer to not run the vortec and potentially have more options. I am not set on staying away from the vortec, but it all depends.

Any thoughts.

 

You can easily get more than this flow out of your present heads. Says they are "ported". Did you have them flow tested? Are they fully ported, or just warmed over?
If they are "ported" you should be above those flow figures already. Only a flow bench test will tell the tale.

The real bottle neck is the intake manifold. Until you switch to a shorter runner design you'll only make just so much power.
I'd be looking at improving the exhaust system. You only have 1 cat. Need two. A custom built header/ exhaust system that helps scavenge and mve air thru the motor will help a lot.

 

What do the 083's flow in stock trim vs. when ported? All I have done is just a minor port job on the heads. Nothing to fancy.

I'd like to know what can be had from these 083's. I have no problem running them if they can put up some numbers. The builders I have spoke with in my area all say get rid of them. They claim the darts and vortecs produce more out of the box than the 083 ever will.

Have you had different results/experience? Ultimately I would like to see 325 - 350 at the crank from this motor if possible.

 

Well for a few very good reasons.
A set of aluminum Pro-1's offer much more power potential than his other choices listed. They are not valve or valvetrain limited on size, or require a special intake manifold to match. They come with screw-in studs, guideplates, bronze guides, and fairly nice valves.
Last but not least is that the epoxied dart port will flow far more than either of his other choices at low, mid, and high lifts. It actually isn't even a close comparison on flow.
You use the term "muck" with epoxy suggesting that you may not have experience epoxying ports, or maybe not have a porter in your area competent with using epoxy. I specified competent because I know there are people out there who aren't good at working with epoxy. Just keep in mind that there are good people out there as well, and many epoxied heads and intakes doing daily street duty for years with no problems.

Well since you asked, that's my explaination of why I suggested what I did. It was just to offer an alternative for the poster after one of his possible choices was shot down so quickly based on nothing but port volume not matching the rest of his engine.

 

You should be able to achieve 240cfm+ @.500" easily yourself at home with a full port job. the exhaust will go over 200cfm.
There is a member here on third gen that got 270cfm out of these heads. That leaves you a lot of room to work within.

Unless you've really screwed up your heads all you need to do is get serious on a port job over the winter, including some chamber deshrouding in the right areas.
The builders recommend new heads because that makes them rich with little effort. (And they don't know how to port heads) You do not want to or need to pay some one to port a stock head. They likely don't know anything more about it than you would after reading a $10 book on the subject. (it is too time/labour intensive to have someone else do it for ya)
I recomend a serious head porting on your present heads.
Or start with another set of 081-083's Or start with a set of Dart SS165cc and do them your self.

if you've just done a little valve bowl pocket porting below the valve seat you'll likely be around 210cfm 195 is stock.
Do your own heads and put the reast of the $$$ into other areas that need attention. You've barely scratched the surface.

Another great head to start with and port up a bit with great results would be a GM Bowtie head.

 

But competent head porters that can make epoxy stay in for 100,000 miles do not work $$$$$cheap$$$. I disagree about ending up with more flow than a ported smaller head by making a big head smaller (you will loose flow and end up with less or the same) at way more cost.
Not one head porter will guarrantee and epoxy job in writing. Your alternative offers no flow or power advantage than starting with a smaller head with reasonable porting preparation either at home or from a good shop and will cost much more in the end.

Once you get away from the big head port is better mindset, you're way further ahead on this built. This is a "torque motor". the intake manifold has limited air flow and rpm potential (pure physics). you need a "torque head" with modest port volume and cross sectional area. thats what will deliver to big fat average torque numbers with good hp too on a 350 ci TPI motor..

 

My experience with heads that are "too big" is basically this... putting on a head that is "too big" for an engine is not a good thing, but nowhere near as sinful as putting in a cam that is too big. 215cc intake runners are probably too big for a street TPI SBC, but won't cause nearly the bottom end torque loss that a 10* too big cam would cause.

Optimal? No, probably not. Recipe for disaster? Again, no, probably not.

 

I do not disagree with 305sbc idea of epoxy BUT that is usually only for extreme situations on heavily modified cylinder heads. This is NOT one of those situations. After all is said and done it is still a TPI motor that doesn't need that much runner volume. Its all in the combination and the money saved on those heads will be MORE than used up in the epoxy work AND you now have the "possibility" of epoxy coming loose and causing some nasty side effects.