When does custom porting become beneficial?

[289nate]

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?

What is the budget for this engine build Rob? It sounds like you want to do a fully developed intake track, exhaust manifold, etc How much are you willing to pay for someone to do that? You mention MAJOR difference and I’m not disagreeing. What you describe is going to cost quite a bit hiring out to someone capable to see a MAJOR difference.

[Walter R. Malik]

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.

When you say "NOBODY" you are certainly not referring to many people I deal with consistently.
However, it usually is more expensive doing things that way and most people just don't wish to spend that extra money

[RobZ28]

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!

When you pay them by the hour and give them their asking price then I guess Im not asking them to accept less money and I dont do the cars I do for less either. I said I do them to keep it interesting and yes, I could charge more, but I don't because I have other income channels and I enjoy the work.
This isnt a "why wont you port my iron heads" thread.

[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.

When you say "NOBODY" you are certainly not referring to many people I deal with consistently.
However, it usually is more expensive doing things that way and most people just don't wish to spend that extra money

That extra money is going towards a better product. There is no comparison. The question remains...

[bob460]

If you want longevity, just put an ls and make it look like a stock factory looking 350.

[RobZ28]

If you want longevity, just put an ls and make it look like a stock factory looking 350.

That’s disgusting.

[Tom68]

Custom porting....when you’re racing in a competitive class that actually uses a rule book.

Street motor give them a cleanup yourself.

[RCJ]

Not familiar with 87 heads but the chamber design would be the deal breaker for me. If it has the small compact chamber like a double hump, vortex, I would use them, if an open chamber nope. I would try to modify a vortec to except that intake. I'm working on a similar style project where I'm trying to get more power under curve and not extend the rpm range. I'm basically trying to get power out of everything else and keep the heads small

[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.

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.

When I was younger I did not want to grind on a head because of all the horror stories about ruining a head with a carless grinder. I was a teacher at a technical college, we built a race car as a shop project. I did not want to grind on the heads and a student with some experience from his dad, did the heads, and I built my first bench for him to use. He was 19 years old, and his work was pretty good.
So, it takes years, maybe to get 100% of what is available, but to get 75% no it does not. At least in my experience. And in fixing several CNC ported heads I think many of those who claim to be really good, maybe are not as great as they think. Especially on OEM iron heads, big results from blending where the seats are cut, smoothing the short turn, profiling the guide boss, and port matching. 25% improvement is easy possible. On a good aftermarket head, blending the cutter marks and a little bump here and there I get 10% improvement and am happy with that. On the CNC heads I fixed they were actually backing up over .5 lift took 30 minutes on each head to fix.

Checking results on a bench, and going slow, and paying attention to air speed on the short turn. Vizards videos are as good as any to get someone started.

[NebrRex]

What is they say about the valve job and the 3/4 in. on either side?


.

[barnym17]

You said your replacing the lower intake so I would modify it to fit vortec heads,give them a little love and you have met your goal.

[Bill Chase]

You said your replacing the lower intake so I would modify it to fit vortec heads,give them a little love and you have met your goal.

Local acquaintance used OEM 062 vortec heads, scoggins dickey vortec tpi base, stock l98 Vette short block stock stock stock. With nothing more than a simple 3 angle valve job, port matching and 1-5/8 long tube headers the car went from 190 rwhp to 215. Zero tuning. It was impressive to say the least. Used a steel shim head gasket to keep quench tight.

[cab0154]

port shape isnt going to matter much because its not above 6k, and as far as airspeed, you are limited (in terms of mean air speed and flow) by the cross section. i say put a set of as cast profiler 195s on it. its not going to matter. the valvejob and chamber will be far more important if the target cross section (and thus flow, and airspeed are good) and velocity gradient of the port is decent.

[dfarr67]

When it comes to heads and cams- I'm firmly in the camp that the newer the better. If you want double humps I think TFS still makes an alum version and powder coat the colour of choice. As far as porting- depends on how good or bad the original canvas is, there no doubt is low hanging fruit the oem won't spend time on and a good valve job.

[rfoll]

You state the car to be a 1987 TPI Camaro and that would mean it has 083 TPI heads. These are a far cry from the 70s smog heads. I just sold a pair of those as cores to my machine shop for $150. They do have value. The factory valve job is terrible. They are a lightweight casting limiting how much you can cut the deck. They need the usual cleanup in the bowls etc. as applied to most factory heads. It is my understanding the TPI manifold is essentially the same as the one on the 305 engines and extremely undersized. Some serious porting there or perhaps an application of the extrude hone process could reap some huge benefits. For a time Edelbrock made a replacement for it that was a huge improvement, but it could be hard to find. The engine compartment on your car is a very busy place and could likely hide non-stock parts if appearance is important. It's not hard to understand why you would like to keep all of the stock parts, your car isn't just some average Camaro.