Another 489bbc question

[imjeff]

Originally Posted by Roll'nSlo

I'm a little confused. Here you said 12:1 and now you're saying 10:1.

E85 has a lot less power per volume and a higher octane which means it does better with higher compression. Getting 700 horsepower with E85 will be an adventure. You have to run them way fat to get power since there is so much less power in the ethanol.

[68c10owner]

When you decide to build a engine you have to match everything. You need to decide what size engine your going to use first. Then what are you going to use it for? What RPM do you want to spin it to? Then you start planning out what parts your going to use.

Cylinder heads-you need to know what heads your going to use on the engine. This will match the use of the engine. If your building a street engine or even street /strip your going to want the smallest runner that gives the most air flow and velosity. Cross section area of the port is important as well. Valve size is important. If you have a big CID engine like over 500" then you might be able to get away with a small square port head but best to go on the smalelr side. For high RPMs then the square ports will work fine but dont usually mix so well on street motors but there are always exceptions to the rule.

Camshafts-Do you want hydraulic? Solid? Flat tapper or roller? Roller cams will make more power and wont require as radical of a camshaft to make the same power of a flat tappet because the lobe profiles are more aggressive. There is too much to get into with cam profiles but lobe intensity,lobe profile and lobe sepereation all play a part. Some engines will make better power with a single pattern cam, some will need a split pattern. It depends on the cylinder heads used. Some have weak exhaust ports like OEM BBC heads and some are very strong like the AFR heads. You cant pick a camshaft without knowing the size of the engine, what RPM and what heads are being used.

Compression-More compression is more power. Tighter you can squeeze the charge the more power it will make. Problem is you can only run so much compression on pump gas before you get detonation. Cylinder head material (iron or aluminum) will have effect on this as well as camshaft over lap. Aluminum heads will usually allow up to 1 full point of compression over iron heads because of heat dissipation.

Intake manifolds-You have 2 styles typically. Single plane which are open and dual plane with individual runners. Single plane intakes usually work best in high RPM or all out race engines and dual plane intakes generally produce better low to mid range torque and throttle response. Again there are exceptions to this rule. Generally you want to match the RPM of the intake with the RPM of the engine.

Headers-smaller tubes will give better low-mid range and throttle response. Big tubes have less back pressure and usually produce the best HP numbers. There is a formula to figure out what size header will work based on engine size and RPM. For street cars its best to go on the smaller size.

It`s not just about bolting parts together, its about planning your combination. Everything comes into play which is why its important to be 100% honest with your builder.

Intake manifold style and headers size play a part in the over all HP and torque numbers of the engine but the camshaft and cylinder heads play a bigger part than anything else.

This is all I can offer the OP. Good luck with your build.

[Super73]

Originally Posted by 68c10owner

This is completely wrong. You need to know what heads your using before picking the cambut the the camshaft and the heads together determine the power band. I have seen dyno where the victor jr made more power across the board over the dual plane when the dual plane should have come out the winner. I have never heard of doing it the way you describe in the 25yrs i've been playing with hot rods.

Please see the bold quote from above. This is why I said the cam is the last item would spec in a motor build. Only after every thing else is figured out as far as supporting components to achieve the rpm band desired can you spec an appropriate cam.

[bbcmudtruck]

Decide on operating range first as well, as desired peak rpm. Then pick your heads and intake. Once you have the flow data on your heads, thats when you pick your cam. Optimal choice would be a hydraulic roller from chris straub. Once you have all of that figured out, then you dyno your motor to get the power curves. Next step is to weigh your truck and call a quality builder to custom build your stall converter with your intended driving needs. Its alot more expensive than just throwing parts together off of the shelf, but you will get exactly what you want the first time.

[Blue Rat]

Originally Posted by bbcmudtruck

Decide on operating range first as well, as desired peak rpm. Then pick your heads and intake. Once you have the flow data on your heads, thats when you pick your cam. Optimal choice would be a hydraulic roller from chris straub. Once you have all of that figured out, then you dyno your motor to get the power curves. Next step is to weigh your truck and call a quality builder to custom build your stall converter with your intended driving needs. Its alot more expensive than just throwing parts together off of the shelf, but you will get exactly what you want the first time.

Absolutely, heads first camshaft second. That's why they make custom camshafts. But on the other hand, your desired use of the vehicle the first thing you think of is what is the operating range going to be? So you set out to devolve a list of parts. So either way one is just as important as the other. Knowing head flow is a must in getting the best effort from the camshaft.

[bbcmudtruck]

Everyone that's posted is giving good advice. 68c10 broke it down very well. My advice is to read, read, read! The more you understand what all is involved in achieving the power desired, the better you can decide on parts as well as inform yourself about other questions or issues you may not have been aware of otherwise. My dad has been building bbc's as well as a few sbc's since the early 70s. He still reads everything he can get his hands on to this day. Technology has made hydraulic roller camshafts in the older mark IV blocks absolutely awesome! I never thought I'd be running one in a 496, but my honest opinion, for a street driven vehicle, there is no better choice. IF YOU PICK THE RIGHT CAM BUILDER! If you pick the right guys to help you with your build, they won't let you buy **** you don't need and point you in the right direction every step of the way. Just be prepared to spend money and lots of it if your wanting a max effort reliable 489! Send me a message if you want details on mine. I'm not quite done with it, however I'm within a month away from firing it up. Its taken me over a year to accumulate the parts needed for this particular 496 build.

[68c10owner]

Originally Posted by Super73

Please see the bold quote from above. This is why I said the cam is the last item would spec in a motor build. Only after every thing else is figured out as far as supporting components to achieve the rpm band desired can you spec an appropriate cam.

But the cam isnt the "last" thing you get like you said. You cant pick intake and headers before you know the rest of the combo. Those are the last thing you buy along with carb and ignition. Without knowing the heads and then knowing what cam, you can not correctly pick a matching intake and header.

The camshaft is the main component that determines the the power band. I cant understand why that is difficult to see. The duration of the camshaft is what changes the power band. You need more RPM? You dont put bigger headers and a bigger single plane intake on it. You get a camshaft with more duration.

[68c10owner]

Originally Posted by Blue Rat

Absolutely, heads first camshaft second. That's why they make custom camshafts. But on the other hand, your desired use of the vehicle the first thing you think of is what is the operating range going to be? So you set out to devolve a list of parts. So either way one is just as important as the other. Knowing head flow is a must in getting the best effort from the camshaft.

Just knowing what RPM range you want to run isnt enough to just start gathering parts though. Knowing RPM range and desired use is very important. And sometimes the rest of the parts that you pick may not be what you think. I`ve seen a vic Jr make more power over a performer rpm when it should have been the wrong intake. The engine will tell you what it wants but these are things you`ll never know unless you use a dyno.

[Super73]

Originally Posted by bbcmudtruck

Decide on operating range first as well, as desired peak rpm. Then pick your heads and intake. Once you have the flow data on your heads, thats when you pick your cam.

Once you have all of that figured out, then you dyno your motor to get the power curves.

Next step is to weigh your truck and call a quality builder to custom build your stall converter with your intended driving needs.

Its alot more expensive than just throwing parts together off of the shelf, but you will get exactly what you want the first time.

I agree with everything said here. I will add a little to it based on the way I do it.


Decide goals
Power adder if any
Target RPM band
Bore/Stroke/Rod Ratio
Heads/Fuel/Dynamic Compression (compression becomes a by product)/Quench
Intake/Headers
Cam

Intake plenum volume, runner length, cross section all aid in tuning for a specific RPM as does header tube diameter, length and collector design.

With out knowing every thing before the cam, you will never optimize valve events. Call any custom cam mfg and they will want to know all of the above before grinding a cam.

[Super73]

Originally Posted by 68c10owner

Just knowing what RPM range you want to run isnt enough to just start gathering parts though. Knowing RPM range and desired use is very important. And sometimes the rest of the parts that you pick may not be what you think. I`ve seen a vic Jr make more power over a performer rpm when it should have been the wrong intake. The engine will tell you what it wants but these are things you`ll never know unless you use a dyno.

Sounds like the wrong cam was selected in the first place. Probably too much duration and overlap to work well on the dual plane.

[68c10owner]

Originally Posted by Super73

I agree with everything said here. I will add a little to it based on the way I do it.


Decide goals
Power adder if any
Target RPM band
Bore/Stroke/Rod Ratio
Heads/Fuel/Dynamic Compression (compression becomes a by product)/Quench
Intake/Headers
Cam

With out knowing every thing before the cam, you will never optimize valve events. Call any custom cam mfg and they will want to know all of the above before grinding a cam.

You agree with what he says? He said heads first, cam second which is the correct way but you keep saying camshaft LAST so which is it?

Originally Posted by Super73

Sounds like the wrong cam was selected in the first place. Probably too much duration and overlap to work well on the dual plane.

Actually I believe it was the customer had to run a dual plane for hood clearance and it choked it off. Sometimes these engines just decide what they want for whatever reasons. I`ve built engines that ended up running about 1 second quicker than what I had in mind. Took some time but the basic long block never changed. We can go back and forth til we`re blue in the face. Nothing is going to get solved and we took the OP`d thread way off course.

[68c10owner]

Originally Posted by Super73

Sounds like the wrong cam was selected in the first place. Probably too much duration and overlap to work well on the dual plane.

I also want to state that I`ve seen many engines with a performer rpm run great in the higher rpms and on very fast cars. Some have tried the single plane and seen little or no change while others have seen 20-30hp difference. The intake is one of those things that you have to try and see what the engine wants, kinda like carbs.

[Super73]

68C10, I agreed with this.. Quoting just in case you missed it.

Originally Posted by bbcmudtruck

Then pick your heads and intake. ..... thats when you pick your cam.

I added to what else I select before the cam and what every custom cam manufacture will want to know before grinding a cam for a customer.


Obviously we are not going to agree here. I'll keep doing it my way no one is stopping you from doing it your way. Just trying to let the OP understand what cam grinders want to know before grinding a custom cam. I am not an off the shelf cam kind of guy.


For reference, here is a order form from Elgin Cams. Please feel free to see what info Dema asks for: http://www.elgincams.com/order.pdf

Here is a link to Bullet Racing cams order form: http://www.bulletcams.com/RecForm/index.html

Tick Performance cam work sheet: https://www.tickperformance.com/cont...mworksheet.pdf

Unfortunately I can't provide a direct link to Dougherty Racing Cams order form but it can be found by clicking here http://www.drcamshafts.com/ and then order form.



I could go on and on. But there must be some reason that every one of them wants to know a LOT more info than just target RPM range and heads, including ALL of the things I mentioned and more. I could only imagine the response you would get from a custom cam guy if you were to say "Here are my heads, here is the RPM I want to turn, grind me a cam and I'll figure out the intake and headers to go with it."


To add to that, you should see what most converter MFG's want to see as well. Most are ok with knowing peak TQ and vehicle weight along with power adder if any.

[68c10owner]

Originally Posted by Super73

68C10, I agreed with this.. Quoting just in case you missed it.




I added to what else I select before the cam and what every custom cam manufacture will want to know before grinding a cam for a customer.


Obviously we are not going to agree here. I'll keep doing it my way no one is stopping you from doing it your way. Just trying to let the OP understand what cam grinders want to know before grinding a custom cam. I am not an off the shelf cam kind of guy.


For reference, here is a order form from Elgin Cams. Please feel free to see what info Dema asks for: http://www.elgincams.com/order.pdf

Here is a link to Bullet Racing cams order form: http://www.bulletcams.com/RecForm/index.html

Tick Performance cam work sheet: https://www.tickperformance.com/cont...mworksheet.pdf

Unfortunately I can't provide a direct link to Dougherty Racing Cams order form but it can be found by clicking here http://www.drcamshafts.com/ and then order form.



I could go on and on. But there must be some reason that every one of them wants to know a LOT more info than just target RPM range and heads, including ALL of the things I mentioned and more.


To add to that, you should see what most converter MFG's want to see as well. Most are ok with knowing peak TQ and vehicle weight along with power adder if any.

Go back and read my posts, I think you missed something. I never said all you need is target RPM and cylinder head info.

What we are disagreeing on is you cant possibly pick a intake and headers and everything else without knowing the rpm range and the camshaft is a main player in determining the rpm range. In all the years I`ve been doing this I`ve never heard of anyone doing it this way. The cam companies need to know all the info so they can suggest or design a cam to fit the desired useage. If you have a existing combo and just changing cams then you`ll have all of the info but if your starting from scratch there is a good chance the customer wont have all of the info and I can guarantee you that those forms dont get filled out 100% complete 100% of the time.

We will definately have to agree to disagree. If your way works for you more power to you.

[Super73]

I happen to like to know what my heads flow with the intake on it. That helps a cam grinder understand actual airflow and how to tailor the cam.

Were you aware some cam grinders are even putting different intake lobes on a cam for cyls 1,2,7,8 vs 3,4,5,6 due to flow characteristics being different due to the intake manifolds runner length, shape and cross section.

By your method of selecting the intake after, none of this could be done.


I also like to see exhaust port flow with a tube the size on my initial primary before any step up in diameter in the header.

[bbcmudtruck]

If you called any custom cam maker worth his salt, without head flow data, he simply wouldn't make you one! You can get great power with off the shelf cams, however if your really looking to up your performance, a custom ground cam is the only way to go. I'm even a little hesitant to say this, but on the 496 I'm in progress with right now, I went ahead and went with the large body roller lifters.. So when the block finally lands in the machine shop, they can fully blue print the lifter bores to the exact tolerances. A very well respected and know engine and custom cam builder stated that you could see as much as 30hp increase with the larger lifters and blue printed lifter bore size. The extra power isn't the lifters, its simply the by product of efficiency and corrected valve train geometry!

[imjeff]

Did the OP ask about getting a custom ground cam or if he could get good HP out of his heads? I guess I'm confused. Since the cam is essentially the brain I generally start there with what I want and support it with the rest. Call me kooky!

[Blue Rat]

There are several ways you can go at it. I thinks he was just wanting to be pointed in a good direction.

[Roll'nSlo]

Wanted to be pointed in the right direction plus was wondering if my heads would be ok stock. I usually leave the cam to whatever my machine shop recommends but will get with Chris Straub and talk to him when I get to my cam.

I've built a lil 355(400+/- according to machine shop) but never tackled a bbc. Just sold my Dodge Cummins to get back into gas.

[68c10owner]

Originally Posted by Super73

Were you aware some cam grinders are even putting different intake lobes on a cam for cyls 1,2,7,8 vs 3,4,5,6 due to flow characteristics being different due to the intake manifolds runner length, shape and cross section.

This is nothing new and has been done for years.

As far as header size goes, how can you pick header size without knowing the HP of the engine or the RPM range of the engine?

This has been slightly entertaining but I really have no interest in going around in circles anymore. Clearly my views are not popular so I`ll keep my opinions to my self.

[Roll'nSlo]

Originally Posted by 68c10owner

This is nothing new and has been done for years.

As far as header size goes, how can you pick header size without knowing the HP of the engine or the RPM range of the engine?

This has been slightly entertaining but I really have no interest in going around in circles anymore. Clearly my views are not popular so I`ll keep my opinions to my self.

Your views and opinions are always welcome.

[softballnrd27]

Here is my 2 cents(with some questions)
Is the truck a long term or short term project? Is it currently running? Do you really want to stroke it?
If you want a stroker big block then just do it in stages or save a little longer to get the right parts. Looking back on my truck's past I would have done things a little different but I can't change that now. If it were me I would start from the bottom up and answer this question: What am I going to need in order to support XXX amount of HP/TQ? Get your driveline in order 1st and then build the motor. 700 hp is no fun if you can't use it bc of a weak driveline. You might have already done the above. If a stoker is really what you want then stroke it and upgrade from there. Get the foundation built and build upon it more as the $$$ allows. Do you have a complete Big block? If so just use the heads/intake and supporting stuff from that until you can put the better high dollar bolt-ons later on down the road.
Everyone has their own way of doing things and there are some very smart people on this board(i'm not one of them LOL) so take all the advice given and use it how you see fit.

[Blue Rat]

I finished this engine last year. Life got in the way, if I had known how long this truck was going to be down. I would have built it a little slower with more cubic inches.

[Roll'nSlo]

Originally Posted by softballnrd27

Here is my 2 cents(with some questions)
Is the truck a long term or short term project? Is it currently running? Do you really want to stroke it?
If you want a stroker big block then just do it in stages or save a little longer to get the right parts. Looking back on my truck's past I would have done things a little different but I can't change that now. If it were me I would start from the bottom up and answer this question: What am I going to need in order to support XXX amount of HP/TQ? Get your driveline in order 1st and then build the motor. 700 hp is no fun if you can't use it bc of a weak driveline. You might have already done the above. If a stoker is really what you want then stroke it and upgrade from there. Get the foundation built and build upon it more as the $$$ allows. Do you have a complete Big block? If so just use the heads/intake and supporting stuff from that until you can put the better high dollar bolt-ons later on down the road.
Everyone has their own way of doing things and there are some very smart people on this board(i'm not one of them LOL) so take all the advice given and use it how you see fit.

I'll answer each of your questions. On the length of the build I don't really have a time frame. Want it done like yesterday but who doesn't. Neither the truck or motor is currently running. Truck is in pieces all the way to the frame at the moment. I want to stroke it for more cubes. I'm waiting to get the engine done and dyno done to see what I end up with. Then I'll tackle the drivetrain. Maybe backwards but it's the best way for me I think. I have a complete 454. Was running when it was pulled out of the truck. It was left in the PO yard covered up. Has a slight ridge in the cylinders and no rust.

I agree everyone has their own ways. I've learned a lot from this thread and appreciate all the advice and input.

[Roll'nSlo]

Originally Posted by Blue Rat

I finished this engine last year. Life got in the way, if I had known how long this truck was going to be down. I would have built it a little slower with more cubic inches.

Nice build blue rat. How many cubes can you get out of a 454? Is it 496?