cutlassefi

Just an fyi.
P.S. "Stock" is as they came back from Knowltens after being CNC'd. The rest is self explanatory.

cutlassefi

Compare this to 261/264 at .500 and .600 respectively out of the box but after a valve job.

kitfoxdave

Mark, thanks once again for some good info!

cdrod

Mark,
Do you have any flow data on iron heads (in stock form) for comparison? Thanks for contributing.

firefrost gold

maybe its just me but no its not self Explanatory. From what I can see you or a customer had a set of heads done at Thunder heads . And is this the flow info ? Did you or the other place do any touch up work ? Is this what you thought it would be or ? Thanks

drjr56

A gain@0.500 and 0.600 but is it worth the cost.Unless some other improvements were seen. Thanks for posting.Stock iron heads flow #'s are on CO somewhere,and ROP I believe.

cutlassefi

As mentioned "Stock" is after they were CNC'd at Knowltens with the stock 2.072 valves.. Sorry I don't see the confusion there.
The next column is after the installation of the 2.125 intakes. The last column is with the 2.125 valves but filling the floor at entry with putty. It didn't help.
Travis Knowlten claims 305-310@.600 with a 2.14 intake valve so he was pretty close.


I'll try to find the as is numbers as well, prior to anything being done. The CNC improved it about 10-15% pretty much across the board, but mostly from .300 to .700.
This application will have a .640 lift cam in it so imo it was money well spent.

drjr56

The prior to CNC vs after should show a nice improvement.Sounds like another nice one's a coming.

cdrod

I'm building a resto-mod, daily driver, with a 350 sbo and 200-4r trans that will seldom see more than 4500 RPM. I want a spirited motor with lots of torque and great throttle response, but will never take it to the track. After a long talk with Mark (thanks again for spending so much time with me on the phone) I'm torn between modifying my stock #7 iron heads or going with out of the box ProComp heads.

Here's my question: At what point does increasing the port flow hurt throttle response and low-RPM efficiency?

It seems to me that porting to increase flow allows more air/fuel to travel through the port at a slower velocity; which will be more pronounced at lower RPM. Wouldn't this hurt throttle response for a street car? The analogy is a garden hose; you can move more water through a larger dia pipe but at a slower velocity, so the water just tumbles out of the end of the pipe. Pushing the same amount of water through a smaller dia pipe will shoot a stream of water several feet.

I really like the idea of using aluminum heads (I can use higher CR, bigger valves, exhaust divider, better ports than stock) but I'm concerned that the BBO sized ProComps will require more RPM to feel the benefits.

cutlassefi

You're very welcome.


But I think you're confusing things. If you installed an untouched set of Procomps like these;
http://www.ebay.com/itm/BERNARD-MOND...0c61c9&vxp=mtr the flow rates are very reasonable. Take a look at them carefully. They really don't flow any better/different than a set of aftermarket SBC heads, at the same spec (28"). The pushrod pinch point on an untouched Olds head keeps the cross sectional area pretty conservative.

But with a better combustion chamber and overall better flow, to me it's a no brainer.

olds 307 and 403

Mark, at what point would Procomp's be too big for a 350? On ROP someone was talking about filling ports for the 350. They are only 188cc runners, many sbc heads are bigger. Do you need 10 to 1 and a large cam to get reasonable performance? I think the big problem is 9 to 1 is only possible with these heads out of the box on a 350. I guess the other problem is low stall converters and 2 something gears most cars come with. Also this isn't the 80's, V6 cars run what the bench mark 5.0 HO Mustangs ran back then. Cars are much faster these days.

coppercutlass

So if the procomps flow comparable to bbo heads on an sbo the flow is too much since everyone say's bbo heads on an sbo are a waste of time. Now from a money spending point of view yes the procomps are great. What's wrong with some ported sb heads . If you can't achive bbo runner size with sb heads and people say porting sb heads will hurt performance then would running bbo sized heads like the procomps be beneficial since they flow like bbo's ? Hope that makes sense. I ask the question because people say for an sb for the street a little bowl work and removing the air bump is all you should do so in theory and based on the info that's out there the procomps are nodiffrent than running bbo heads which I belive I asked and most said it would hurt performance.

therobski

The other benefit I see to stock Pro Comps or Edelbrocks over cast iron is they are lighter, my engine runs cooler. My Edelbrocks are stock, I had the Torker port matched, running 10.5 compression 36 degrees advanced timing on 93 pump with no pings at all. Motor runs in 160-165 degree range and in the dead heat of a Dallas summer 180-190. I believe cooler is better on these beasts, but what do I know?

olds 307 and 403

With the BBO or even what I am doing, a big ci SBO, then aluminum makes perfect sense. Question is how streetable is a 10.5 to 1 350?

coppercutlass

Should be fully streetable . That's what I'm doing. Going to run and ignition box. All other factors will be in check .

therobski

I think the aluminum heads and intake really help dissipate heat, the motors just run better to me.

cdrod

copper:
When you say "run an ignition box" is that an MSD type box? What benefit is there to running an MSD box? I've haven't messed with an MSD before, just ran a good HEI with hi-voltage coil and wires.

cdrod

robski:
I'm in Houston, so your cooling comments are good to know. I really notice the lower performance in summer when it's 90-100 degrees outside. What kind of HP/TQ are you getting from your motor? What's the gas mileage like?

Thanks!
Rodney

coppercutlass

The benefits of an ignition box is more spark , stronger spark, So you get a more complete burn and in turn more power.

cutlassefi

There are some that think roller cams are a waste too but that doesn't mean anything.
You can't use a mechanical pump on a sbo with the aluminum heads.
You'll most likely have to mill the heads .060 or so to get an optimum compression ratio.
Some say the ports are too big for a small block. Tell HP TV that. They made 380hp+ and 410 tq with a mild cam, (222/230@.050).

But I'd buy aluminum heads for a small block in a minute, especially if the ones I had needed a bunch of work.

P.S. I corrected your post a bit to make it more readable, at least to me.

coppercutlass

Yep I wrote that on the phone so I don't have auto correct lol. What about port velocity everyone say's port velocity on the sb is important. If you are using the procomps wouldn't a runner that big slow it down ? Now im lucky dave 67cutlassfreak is doing my #6's other wise if I had to sink money into them I would go procomps . No doubt about it. Now it's obvious the chamber is a lot better on the aluminums but is the better chamber a big enough gain to over look the bigger runners. Would making the ports smaller make more power on a "mild" small block as far as the aluminum heads go. My last Question Didn't edelbrock claim 397 hp or 400 with that rpm cam and intake set up with iron heads. I belive you had the scoop on that build . If you do can you compare the hp build to the edelbrock build. Not trying to be a smart *** either . But lets see a real comparison here. Hp tv made 380 with eddy heads how did edelbrock make more with iron heads and that lazy rpm cam. What did they do to those heads etc. etc.

coppercutlass

http://www.edelbrock.com/automotive_...7112&submit=go

olds 307 and 403

Copper, I bet the Horsepower TV build would easily use pump gas and be more street friendly. It also depends on whose dyno is more generous. Like I said, having Edelbrock come out with a head with a 10cc smaller chamber like they do for Pontiac would make them more attractive. Not only do the heads need milled, so does the intake. Of course Edelbrock's intakes are known to be far from straight as cast.

coppercutlass

I still feel for all the money they had in the heads and valve train such as the roller cam and all that. 380 is pretty lame. I think that rpm cam needs 10 to 1 or high 9's to work well in a setup . I do believe mark shed some light on how edelbrock got those numbers. Im curious to find out. If "streetable" makes someone happy and 380 is the out put then I guess that ok. But id rather run on the ragged edged and have significantly less into my combo and still be streetable (to me atleast) and make the same power or a little more. If the engine made more power with a more "restrictive" intake wouldn't it make more with less runner volume that would be more suitable for a smaller engine specially if it's mild you would want more tq. Just thinking out loud here. Don't get me wrong for certain builds the aluminums probably work great and are worth it. But is it always good for power. Could that hp build make more power with a well set up pair of irons ? They proved that bigger isn't always better with the intake swap.

therobski

CDROD, when I had the motor on the dyno all I had to work with at the time was a stock 600cfm Edelbrock carb for the initial start and break in. I should have waited until my Dean Oliver 800 CFM Q-jet was ready. That said, the motor produced 430HP@5,100rpm with 500 lbs. of torque@3,100 rpm. The machine shop guys said I probably lost 40-50 hp with the 600 rpm carb. The A/F ratio was very lean. I don't know the gas mileage all I know is when I get close to a 1/4 tank I'm looking for fuel! I have a 2001 ( somewhere in there) Suburban radiator-for a 67 it drops right in, however I had to use sleeve reducers for the hoses to fit-no biggie.

cutlassefi

The stock headed Edelbrock build made 397hp.
However one of their techs told me it had "extensive" bowl and port work. The intake was port matched, 9.5:1, and it had a 750 carb on it.
Plus we don't know if it was dynoed at 100 degrees or 170. My bet is the former.
I have a set of stock Procomps in my shop. I'll take a pick of the intake ports and you guys can tell me if the ports are too big for 350ci.

coppercutlass

Ok so we can say the builds are somewhat comparable in hp levels appx. and streetable based on compression ratios. lets say there is some hp loss once it's up to temp would that place it in the same range as the hp tv build appx. Lets say you went up to an even 10 to 1 which is still safe on pump gas. My point being the edelbrock build is similar in the power levels but cost significantly less. imo. Based on the fact they ran the edelbrcocks.The procomps are a different story but I still feel even if the hogged out those sbo heads they weren't close to what the stock edelbrocks are volume wise. I think for a guy who is serious about doing a budget build and porting his own heads and having a decent set freshened up it's still good to do irons. That is not to say superior but power can still be made on irons. That edelbrock build is something the average guy can probably do and tight budget and still run respectable hp on pump gas and iron heads.

64Rocket

For me, I think we need some figures on the stock heads, just out of the box.
that way we can see the difference from stock to ported.
Looking at your chart, I don't it is worth filling the intake port.
Was this CNC job for mild street or HPo strip?

Gene

cutlassefi

As mentioned it was about a 15% difference across the board on the intake side.
And does anyone think this intake port is too big for a 350? I don't. Don't look at the opening, look into the runner, it's not that big.

coppercutlass

compare 2 ports . side by side. hard to compare sbo head to bbo style head with out a true fugure to compare against.


So what would the power difference be between running an engine at 100 degrees and 170. Hp number wise. I still feel that that hp tv olds build was a money pit when compared to the edelbrock calimed 397 hp. I actually feel that's a good comparison iron heads vs aluminums as far as a build goes. Seems that was never answered. Everyone has been praising the aluminums but here we have 2 comparable builds to pit the alum. vs. iron head . Both a street engine , Small block olds. The iron headed edlebrock build makes claimed 397 and hp TV's 380. The hp build had a bigger carb better heads , probably better rods and parts all around. The edelbrock build had old iron heads which even if ported cant come close to the edlebrocks. Even if they ran it at 100 degrees They are very close I think specially since many builds walk the lines of the hp levels of both these builds.

cutlassefi

Too many variables, we don't know all the specs/conditions on both. Plus I'll bet the iron headed dyno numbers from Edelbrock were a little happy, or certainly optimum. By their own admission the flow numbers posted on their website for the Olds head are off by about 10%. That kinda makes me wonder.

I'll measure the opening at the pinch point and let you know.


P.S. I corrected your post again. I hope you assemble things with more care than the way you type.

coppercutlass

None of my engines have failed due to assembly. Mostly severe abuse on old *** parts.

coppercutlass

Mark Again what would the difference in hp between 100 and 170 appx. It seems we are dancing around this. Im putting these 2 builds against each other because one is iron headed and one aluminum. Both built by reputable builders and im sure good parts and practices where performed on both sides. So how can a flat tappet , iron headed engine make more hp than a roller cammed , aluminum headed engine . IM sure there are variables. But im also positive both builds saw good parts so I see it as a good comparison. I still think iron heads aren't as bad as they made out to be for mild builds. Don't get me wrong the procomps are good budget wise but all the might as wells that I feel "builders" would suggest will still make them some what expensive. Real deal edelbrock heads on an sbo to me is a complete waste of money when irons heads with little work port are capable of supporting 400 hp.

cutlassefi

I can't state my views any more than I already have.

coppercutlass

Well my point being that in black and white the iron headed sbo by edelbrock made 397 hp or thats whats claimed by edelbrock vs hp TV's 380 hp with aluminum heads. So say the 397 edelbrock claims really made made 377 with the 170 degrees. Imo still pretty close regardless of variables. I was told when I had rocket racing do my heads by them that with what they did they where capable of supporting 400 hp and all I had was oversized valves and bowl work that's it. With any builds there is gonna be variables the big picture here is that the 2 builds performed very similar imo and one had a lot in parts specially the heads for a very pathetic imo 380 hp for the money they probably had in it. I was just pointing out the obvious that 380 is pathetic with aluminum heads and that edelbrock made 397 or a "corrected" 377 appx. with irons. I would be tempted to dyno the current engine im working on but dyno numbers don't mean anything to me it's all about what it's putting down at the track.

cutlassefi

Here you go;
https://classicoldsmobile.com/forums...edelbrock.html

J-(Chicago)

Coppercutlass has a valid point here.
380 horse with "extensively ported" aluminum heads isn't going to make people want to go out and buy the "magic horsepower beans".

Most people already think their "golden rocket 350 from a four-fourty-2" is 500 horsepower from the factory anyway.

They should have juiced it even more if they wanted to sell more heads hahaha.

cutlassefi

I think you have the facts mixed up. The HP tv build that made 380 was with out of the box Edelbrocks. They were essentially untouched.
And if you saw the video, the fact that it wanted a bunch of timing tells me it didn't have a lot of compression in it.
I stand by my opinion, it's apples to oranges.

Thanks.

coppercutlass

I still think that 350 hp tv did was pretty anemic for all that work it had. Probably the worst example of how to get hp from an olds. If a guy who was considering a chevy swap saw it and saw how much money they sunk into it he would probably go buy a 383 stroker for 2 to 3 k less than what it cost to build that weak 350. If someone came up to me said I make 380 hp and have all this effort and money I would probably lmfao and ask them if they got a tub of Vaseline with that. 380 hp with all that money into it is a joke to me but maybe im just an @$$hole or brutaly honest. The olds community is like "sweet hp tv did an olds and sb to boot" . Too bad it sucks. At least my builds impress for the buck to power ratio. Short lived that's a 50/50 so far for me but I have ran faster than many guys with double the amount of money in their stuff. Unfortunately you get people who send an engine out pay out the @$$ and end up with something like hp tv did because they thought it was the bee's knee's . What they are left with is an underpowered engine they spent wayyyyy to much on. But then again it seems the trend is many guys get scared into sending their stuff out and no one is willing to actually do the hard work like porting their heads. Is the build correct absolutely im right there with you mark but it's an underpowered turd.

cdrod

Joe:
I live off Westheimer on the west side of Houston, but I'm lucky enough to have a shop in the unused warehouse space at my recording studio, which is on the southeast side of town. Are you in Houston as well? My avatar pic is of the last Cutlass that I restored in 1989 and drove for 11 years; it was my 4th Oldsmobile. I sold it when my kids were born the 2-door with car seats just didn't work - an SUV seemed the way to go. But my kids are hitting their teen years now so I'm going back to my roots.
I used Custom Automotive Machine for my last engine. Who do you recommend?

I've attached a couple of pics of my project. the first 2 show where I fould her in a Texas cow pasture, the last 2 show the current state as I replace the floor pan.