When does custom porting become beneficial?

[RobZ28]

I have been working on a project for sometime. I've literally spent a good 50-100hrs on this project already trying to understand the best route to approach my goals and I dont think this is uncommon. As a matter of fact I know a lot of guys who do the same thing when planning any engine they are going to use for a project. Long story short, Im having problems narrowing down a cylinder head so, In search of cylinder heads I called a guy today who shall remain nameless but this is a very popular cylinder head guy whom I consider to be very intelligent... and he told me something that hit me. He said for an engine under 6000rpm it's not going to make much difference worrying about the CSA in your head or your intake. Theres too many other factors going on at those engine speeds.

This to say the least had a profound effect on me and honestly, I didn't like to hear that. My response was pretty much, I guess I'm just wasting my time then? His response: Pretty much. I don't agree with what he said but Im not an expert. I believe a well engineered engine that is designed for a particular application can have a MAJOR effect on how the engine performs for that application. Even under 450-500hp levels. I think the custom porting for a given application can have very positive effects on tip in, cruise, bsfc, tq, hp, you name it! Especially when youre working on an oddball project that has limited parts availability. You almost have no choice if you want it right.

So it begs the question, when do you consider custom porting to be beneficial for an engine vs just bolting on out of the box parts? Do you guys build custom engines for cars that arent race cars?

[rfoll]

The under 6000 rpm sort of tells the story. These days it is fairly easy to buy what you need in terms of cylinder heads. There are so many options available in off the shelf stuff. You didn't specify how "odd ball" your project is. Good heads for an ancient Y block Ford can be difficult. Otherwise, custom porting is very expensive and it would seem the money better spent on somewhere else. I'm one of the large group of people that choose to run SBC stuff on my street, (daily driver), motors making Vortec heads a standard choice. I agree with your goal, I have managed to be able to get everything just right on all of them and the rewards are there every time I start a car. Regardless, every time I an engine there is always that what would I do different next time.

[hoffman900]

Odd ball package
Class racing
Something really weirdly specific (power wise, or just want to spend the money)

You V8 guys have some wonderful stuff available to you OTS that if you’re not limited by rules or availability, makes almost no sense to go custom.

FYI: I consider CNC packages from people like Chad and the like as OTS.

[mag2555]

Please tell us what motor this is and ball park hp amount that would put a smile on your face.

[RobZ28]

The under 6000 rpm sort of tells the story. These days it is fairly easy to buy what you need in terms of cylinder heads. There are so many options available in off the shelf stuff. You didn't specify how "odd ball" your project is. Good heads for an ancient Y block Ford can be difficult. Otherwise, custom porting is very expensive and it would seem the money better spent on somewhere else. I'm one of the large group of people that choose to run SBC stuff on my street, (daily driver), motors making Vortec heads a standard choice. I agree with your goal, I have managed to be able to get everything just right on all of them and the rewards are there every time I start a car. Regardless, every time I an engine there is always that what would I do different next time.

I think he either thought I was wasting his time or he didnt want to waste his. Pretty simple. But... Thats just it, there arent as many cylinder head options for guys wanting to run iron heads vs back even 5 years ago. Oddball is relative, but considering next to nobody makes high performance intake parts for my car anymore which makes stuff harder to get. The reality is far more complex. This is the third car I've reached out to get a custom engine built for. The first one was a completely old school build that complimented a really nice 77 Z28 I had. I wanted it built with custom ported camel humps using a Winters intake I had with a solid flat tappet cam. Just like back in the day. NOBODY wanted to do it. I gave it 3 months and no takers, just guys who wanted to change it and do it their way with modern parts which is totally missing the concept! The next one was my 71 Chevelle, which I wanted a 396 BBC built for. Again, nobody jumped on the idea and it fell by the wayside. I ended up contacting Blueprint Engines for the engines and was decently satisfied as those engines ran great for the price. It however wasnt what I wanted and totally misses the point. Thats a lot of money that could have been going back to these guys they missed out on. The problem is nobody wants to invest the time in anything that isnt popular because it takes more time than what what they can charge for. The funny thing is I restore and repair cars for customers who know how much of a stickler I am for giving them a good product. I dont open or close doors by anything but the handle, I used full face fender covers, I watch where I put my hands. I dont put the car in any predicament and make sure I give it back better than when I got it. So I understand but I have to ask, how boring does it get doing the same thing over and over again? This is why I like to do projects like my customers 69 Nova every now and again vs the better paying stuff that doesn't take as long. It might not pay as well but it's at least a break from monotony and is interesting... Regardless... Im doing this project.

[rebelrouser]

I build a lot of engines like you are talking a bout. Muscle cars that guys want to look period correct but run better than they did in the 60's and 70's and almost every one of them asks for a cam with a lope at idle just for the sound of it. I have a flow bench and I port my own heads. I am sure lot of guys on here can get more flow out of them, but some bowl work, port match them and a multi-angle valve job from my experience on the dyno and an engine program gives the customer about 25 horsepower, and the idle and throttle response is noticeably better. I don't depend on anybody for my engines, hence the homemade flow bench. Don't argue with a head porter buy a grinder and go to work.

[modok]

If you want to port old heads you probably need an old head guy.
This could be a good place to find that connection.
Porting can take an hour or week depending on what you want done to what.
I'm still unclear what the job is.

[NebrRex]

I believe a well engineered engine that is designed for a particular application can have a MAJOR effect on how the engine performs for that application. Even under 450-500hp levels. I think the custom porting for a given application can have very positive effects on tip in, cruise, bsfc, tq, hp, you name it! Especially when youre working on an oddball project that has limited parts availability. You almost have no choice if you want it right.

So it begs the question, when do you consider custom porting to be beneficial for an engine vs just bolting on out of the box parts? Do you guys build custom engines for cars that arent race cars?

Sometimes you have to work with what you have. I see nothing wrong with applying technology and techniques to modify a part to fit a different application. As long as it does not exceed the capabilities of the part.


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[modok]

But one thing that does bother me is people don't understand how many different engines there are in the world. There is no way even with a full lifetime that one could know all the fine details of every cylinder head that currently exists. And they are all a little different, tho there are a lot of things in common.
Not to mention all the possible applications and situations.

[RobZ28]

I build a lot of engines like you are talking a bout. Muscle cars that guys want to look period correct but run better than they did in the 60's and 70's and almost every one of them asks for a cam with a lope at idle just for the sound of it. I have a flow bench and I port my own heads. I am sure lot of guys on here can get more flow out of them, but some bowl work, port match them and a multi-angle valve job from my experience on the dyno and an engine program gives the customer about 25 horsepower, and the idle and throttle response is noticeably better. I don't depend on anybody for my engines, hence the homemade flow bench. Don't argue with a head porter buy a grinder and go to work.

Porting heads is an ongoing profession that takes years to get good at IMO. It's not something you can just buy a bench and pitot tube and get it done or else I would. I'm sure I could paint a Mona Lisa, but it wouldnt look as good as Leo's.

25HP and better driving characteristics is definitely an improvement and I also see similar gains with other customers cars. Sometimes I see as much as 80hp using stock parts. We did a 69 442 with a 400 that did 389hp with stock and near stock parts which worked out real good. Other times weve done Jags (60's) that gained about 25-30hp with valve job work, some minor cylinder head work and internal carb stuff.

Since people are asking, its a 1987 Camaro IROC-Z with 27,490 original miles. Its a time capsule. Its the first year 350 car with TPI and 4 wheel discs. Paint and interior are as perfect as showroom. The oil pan, rear main seal and valve stem seals are leaking which is whats prompting all this. I don't appreciate the big plume of smoke coming out of the tailpipe when I start it nor do I like the oil burning smell when I drive it. Pretty understandable. Seals are old, regardless of mileage... so If I have to pull the engine out to fix this stuff, why not get it more in line with todays performance standards and keep it looking original at the same time? The job concept is simple... keep the car looking completely original while adding some power. Im not asking to move the Earth. Just enough to stay out of a new (insert import FWD V6s) rear view mirror. So 275-325rwhp. 350-400hp crank. The car is a MAF car so that will help it run well with changes and I have already purchased TunerPro, Ostrich 2.0, Burn 2, Xtreme ALDL, and all the chip burning tools, cables, eraser, etc. so I can tune it if I need to.

Were working with the TPI bottleneck which is a 2.14 CSA intake runner diameter that measures 1.650" round. The next problem is the stock base will only port to 245cfm or so. Once bolted on to a head that flows in the 270 range you get about 220cfm out of it. So the base HAS to be upgraded and still appear original. Aftermarket bases will flow 260-290cfm ported. This should help the project make the power needed without making it look butchered. About the only thing that doesnt look stock is the exhaust. It has a full exhaust already. 1 5/8" short tube headers with ceramic coating, 2.50"-3" exhaust y pipe going to a 3" Magnaflow exhaust system with dual outlets. This post is getting long...but the point is... There isn't an off the shelf good head or intake option for this project. This isnt a AFR 210/Holley Stealth Ram/406 kinda deal. I am going to need custom porting done.

[steve cowan]

I can see both sides of the coin here -
For a effort to performance percentage porting period correct heads,intake will be a time/ cost lot of deal.
I can see getting a genuine 450hp from a 327- 350 cube with stock parts not as easy as people think without spending money.
Most small business owners would not work for under $100/hr in this day and age.
This might sound a bit odd but I would go to the race track and talk to some stock eliminator or nostalgia racers and they might put you in touch with someone that actually does that type of work.
If I was working on a engine that was not coming apart for 10 - 20 years I would focus on longevity
As in ring seal,rocker geometry, oil return/ crankcase ventilation etc for years of turn key ,leak free fun.

[RobZ28]

I agree on longevity. I am also looking into those aspects. I do want it to last and be trouble free but Im not sure the super stock guys with epoxied ports and 280 duration cams can add a lot of usable info. Chad Speier does that kind of work but again, his primary goal is feeding a 350 at 8000rpm. This is way different than what theyre doing. I would like to get a good look at their exhaust manifolds though. If you guys can propose any ideas that would help, I am all ears. So far all im finding is as much airspeed and cfm as I can get out of a small port thatll see 6000rpm MAX.

[RobZ28]

If you want to port old heads you probably need an old head guy.
This could be a good place to find that connection.
Porting can take an hour or week depending on what you want done to what.
I'm still unclear what the job is.

I have a porter already.

[289nate]

You mentioned, you are willing to take less money to work on a different type of car to keep things interesting. What about what you are trying to accomplish with your build is supposed to be new and interesting or challenging to the type of people you are attempting to hire?

I can’t imagine a cylinder head porter who looks at an old stock iron head and feels compelled to work on it just because aluminum has become too easy to work with. Unless it is for a class racing effort or a family member. Porting iron is a big heavy nasty messy pain in the rear!

[289nate]

I really do think you and the goals for this build are the perfect candidate for a do it yourself effort. It wouldn’t be terribly difficult to get 90% of the gain doing it on your own. You’ll never feel the difference driving it around on the street and burning the tread off of the stock type radials.