Back it up and quantify it. It's that opinion thing again.


Exactly - using compression to bleed off compression is not a reasonable "trick" for a street engine - it just makes for a pig at low- and mid-throttle as you note. So how useful is this purported increase in CR? This was exactly my point - at a streetable CR, it simply doesn't matter.

You look at every engine through 500 HP-colored glasses...which is why I push back every time you try to force this type of thinking on a street-type builder.

And, as usual you misdirect. On what planet is it reasonable to compare a tier 1 head with a 180, 195 or 200cc head - or an AFR costing nearly 3x as much? Stacking the deck again, I see The answer could be considered incomplete if you completely ignore the OP's question and approximate power targets - he's not going to spend $1500 on a set of AFRs... This is more nonsensical if we consider the OP's scenario - he's got a working set of Vortecs that just need a refresh - so investing $1500 vs. maybe $300-450 for possibly 20 HP seems like a very poor investment.

it's worth taking time to understand the question and respond appropriately - so, for example:

Please identify a tier 1, basic head with significantly more than ~230CFM intake flow at ~.450.

 

Here is the gist of what I am trying to say. Matched components provide better power than mismatched components. If you are going throught the expense, time and effort to build a 383 use matched components. A 170 cc head on this big of engine is a mismatch. A sub 450 lift cam is a mis match. If you want to use a streetable cam aluminum heads will allow you to bump compression a half a point with better power across the entire RPM range than iron heads. A 9.5 to 1 compression 383 with vortec heads and a sub 450 lift flat tappet cam will be lucky to hit 400 HP. A 10 to 1 aluminum head engine with a roller with the same duration @ .050 will likely be pushing 450 hp with the same operating range, better vacuum , better streetability and noticably more power across the entire operating range of the cam. This is going to cost you another $1000. All facts, don't want to argue, do what you want, Im out.

 

You're once again spinning the discussion completely - there are plenty of Vortec-head 383 builds out there, and if the power target is in the low 400's, that *is* a matched component.

The challenge here is that you continue in this perspective that every engine needs to be a 500 HP engine or it's "not fast", never realizing that this is simply beyond the means of many engine builders.

 

NO Spin here just facts. Just in case you didn't bother to read my last post.
A 9.5 to 1 compression 383 with vortec heads and a sub 450 lift flat tappet cam will be lucky to hit 400 HP. A 10 to 1 aluminum head engine with a roller with the same duration @ .050 will likely be pushing 450 hp with the same operating range, better vacuum , better streetability and noticably more power across the entire operating range of the cam. This is going to cost you another $1000. All facts, don't want to argue, do what you want, Im out.

Your "cheap" vortec heads require different rockers, springs, valve covers, intake and the price of the heads. Add the numbers up. Then you still have a set of stock, heavy iron heads with too small of ports for a 383 and flow and lift maxes out @ .450. A set of assembled Aluminum Dart SHP 200 heads are $930 at Summit and bolt on.

Dart SHP 200 @ .500 intake 261 exhaust 172
Vortec 170 @ .500 intake 225 Exhaust 149

 

All opinions, not facts, and still based on your perspective that every engine must make 500 HP.

Vortec heads require none of those changes depending on power targets.

I build enough 383s to know what I'm talking about. Not 500 HP beasts - but much closer to what the average guy would build. Your math and experience is quite incomplete if you're under the impression that a 500 HP 383 costs only $1,000 more than a 400 HP 383....but I've made this point a number of times and you clearly just don't want to connect the dots.

 

Didn't think you read my post, that is why I repeated it and your still misquoting me.
Never said anything about 500 HP. I said pushing 450 and, yes it cost $1000 or less to upgrade to 10 to 1,Dart SHP 200 heads and a roller over a 9.5 to 1, Vortec and flat tappet with similar duration @ .050. and yes it is worth about 50 HP, noticable power increase across the entire operating range of the cam and better vacuum and streetability. I have made this point a number of times and you don't want to connect the dots. Nothing wrong with my math or experience. I do question that you don't need a spring upgrade with stock vortec heads, seat pressure #80 or different rockers or different intake or different valve covers. Last I checked these are different than your typical C3 and it don't depend on the power target.

 

This is freekin rediculous. Do what you want and I will do what I want. If you recommend 170 CC heads for a 383 I will argue the point, GM put 151 CC heads on a 305 and the GM Fastburn 383 uses 210 CC aluminum heads. They had vortecs available, chose not to use them, Used vortecs on their 5.7 truck engines.

 

I do, and I respond quite carefully with no misquotes. The fact remains that we come at this from two very different perspectives and experience bases. I build a bunch of 355s and 383s making around 1 - 1.2 HP/CID. You build stuff that appears to be all over 1.4 HP/CID. You expect everyone wants what you want - and I continually note this is not the case. I also note that as power increases, so does the cost of the build overall, including the chassis, suspension and brakes required to make use of the power.

A cast crank, hypereutect piston, Vortec-head 383 is one of the most popular builds in the country, and for good reason. It delivers outstanding power, and more importantly, it delivers that power at an excellent price and a fantastic $/HP.

There was a 383 build here with "must have MOAR" input that took something like a year and cost $14K and made...something like 450 HP? I could have built one making a little over 400 in two weekends for $3,500 or less. And that's $3,500 ready to drop.

I connect the dots quite well - about 10x/year I provided feedback on the OP's question and a few follow-ons; I didn't design an engine for him - and there's no reason for this to get so intense. I believe your ad-hoc recommendation was a set of Iron Eagles...so now positioning AFRs, etc. is a bit hilarious.

I'm not going to convince you, you're certainly not going to convince me - and the OP and readers have enough information to make up their own minds.

 

You will, and I will. Is it so important for you to be "right" than you can't acknowlege another perfectly valid approach? I imagine you'll continue to obsess and edit and re-edit your posts...but it doesn't really change anything.

Yep, Vortecs are truck engines. So is every Chevy SBC ever made, including the LS series. It's a nice idea to try to denigrate them...but of course that masks the fact that the are the single most popular heads out there. As for GMPP engines, who knows how they make their decisions - we've had this conversation in the past and agreed there are some odd parts in that bin...yet the HT383 uses them, as does the 350HO.

Are there better heads that make more power? Certainly. But if the power targets are appropriate, they remain an absolutely fantastic pair of budget heads for SBCs making around 1 HP/CID.

 

Not the case. Most of my builds have been in the same range as yours. Elle88's build was 505 HP out of a 440 CI. < 1.2 hp per CI. Actually a 450 HP 383 is < 1.2 hp per CI as is 400 HP. There are hundreds of ways to do this and if the OP is looking at budget the Iron Eagles are a good option with the same flow numbers as the SHP heads for less than vortecs. I do have a tendancy to overbuild the bottom end and driveline as I come from a racing background and have blown up plenty of engines, transmissions and rear differentials in my day due to not building things strong enough for their intended use. Live and learn. Truce.

 

Look at your budget and buy the best you can aford. Nobody gives away real good new heads. You are getting what you are paying for. If it were me or a customer, I find the max they are willing to spend and go shopping. Start at the top and work your way down the quality ladder. At some point you'll find yourself saying "Yeah I can do that" and you'll be happy. If you spend time and money splitting hairs at the "best of the worst" you may not be happy with whatever pair you pick. As you can see there are many opinions regarding engine building. It's difficult to say one guy is right and the other is wrong. They all have good points maybe some bad. I don't always agree with everybody either. When all else fails look at the money. Performance engine part business is so competitive that the costs (generally) indicate the quality.

 

I do have a tendancy to overbuild the bottom end





Also do I. I hate to turn the same bolt more than one time. The top end you can build and change to suit your needs built on a solid foundation.

 

 

Vortec head from GM. 1950s pressed in studs just waiting to pull out. Then you have to change to different intake manifold, rocker arms, valve covers. If your buying new its a very bad option now that the cost of new aluminum heads has continued to drop. Add in extra shipping costs to ship the heavier iron heads.

 

Yep, the same pressed-in studs that have worked well on tens of millions of SBCs

Pressed-in studs typically only pull after a head has been hot-tanked; I've never seen or heard of a pulled stud on a stock set of Vortecs.

GMPP self-aligning stamped rockers, $65. Center-bolt valve covers, $20 on most auction sites. For a new build, the intake is a wash.

230 CFM flow and excellent mid-lift flow still make these a great choice for the right build. Lots of good choices at around $1K+, but for a budget build making around 1-1.1 HP/CID they're still one of the very best choices...and a steal at around $625/pair and around $1k for the whole smash...all of which accounts for their continued incredible popularity.

 

Yea i know all about general motors crap and why they went out of business had to be bailed out by the goverment. Durability crap like pressed in studs is why everyone went to toyota, honda, nissan anybody else they could find. Next you will tell me how well pressed in oil pickup tubes work. Funny thing i bought a new 69 Z/28 was flying down the freeway late one night with only 18,000 miles on the car the pressed in pickup tube fell in the pan it spun two rods. My Z/28 got a new crank two new rods. In 1957 my grandfather bought a new buick just a cruiser the pressed in pickup tube came out into the pan dealer had to put a new engine in the car. 12 yrs past from 1957 to 1969 GM still with pressed in crap in the oil pump. One thing i do have is ethics but not GM. I would never ever for any reason build an engine for someone else with crap pressed in studs my good name means more to me then that. Truth of the matter is ball stud design is total cheap crap, cheapest Junky way GM could build it.

As mako said the vortec is a truck head. Tell me this if you buy an over the counter vortec head ment for performance use there 180 runner bowtie head why does it suddenly have screw in studs. Not 1950s pressed in studs. Now we know 180cc runners are not any big bad racer boy crap now is it, obviously just for mild builds. The pressed in crap is gone in the 180 runner head.

 

lets add it up with your numbers.
Vortec heads $625, (upgrade to Scoggin-Dickey SD8060A with .525 lift $780)
stamped rockers $65 or upgrade to roller tip or full roller at your option
valve covers $20
Springs $80 (stock vortec heads have #80 on the seat)
Labor and time to properly set up new springs ($50 minimum)
Total $840 minimum, $865 for Scoggin-Dickey SD8060A set up with upgrade springs.
You still have
iron heads (shipping weight #46 each)
pressed in studs
1.94 valves
limited lift @ .470 before retainer contacts valve guide. -.060 if you want safety factor. Measure them
170 CC runners

Dart SHP 200
reuse stock rockers or upgrade to decent roller or roller tips at your option.
reuse valve covers.
Come with correct springs if ordered correctly.
total $930
Aluminum heads Shipping weight #23 each, 1/2 the weight
screw in studs
2.02 valves
lift to .620 with safety factor.
Come with guide plates.
200 CC runners
13% better flow (that is 13% more capability)
I know 13% don't sound like much but 13% of 400 hp is 50 hp.
Then you have to figure the performance increase of being able to use a higher lift cam.

The above facts are why I feel that in a performance build, esecially a 383 I would spend the extra. It is less than $90 if you figure shipping. $90 well spent.

 

Here is a great article on intake port volume sizing from Dart written by David Vizard. Test engine is a typical 9.8 to 1 budget build street 383 dyno tested using 180, 200, 215 and 230 CC intake ports. These are all dart heads so it is not an apples to apples comparison with vortecs.
http://www.dartheads.com/tech-articles/port-volumes/
According to this article a 200 CC port was best overall. The chart at the bottom also confirmed that a 170 CC head is adequate for a lower rpm 400 hp build but the valve size and lift also would be a factor so I guess it all depends on the viewpoint and other factors that are not addressed in the testing.

To the OP rebuilding the vortecs is likely not a winning proposition. You could rebuild them, machine them for new springs and decent lift, pin the studs or machine them for screw ins, They can also be machined for guide plates. This all cost money better spent on new heads. Pro Comps are not the way to go. I would weigh the information given, sell the vortecs you have and purchase the heads you feel are the best fit for your build.

 

So much anger. Do you still own any GM products? If so, why do you still own such "complete crap"????

 

I understand Little Mouse's point. The bean counters cost GM a lot of issues over the years on sacrificing quality for price. This is kind of where the pro comp discussion ties in, Pressed in studs have been the standard on small blocks for 50 years. That said those cams were tiny with slow ramps, weak springs and low lift. GM did use screw in studs on any performance build. I think it is a good idea in any build your upgrading the cam lift and ramp speed in, using stronger springs or if it will spin over 5500 RPM. I have pulled a couple studs in my time. One pulled out enough to pop the lifter out of the bore. I shut it down in time to save the bottom end but it was a lot of work to put it back together. Had to take it down to the short block. Screw in studs went back in it.