Head help

[4-play]

I need help on picking a Iron head.
I have a BBC 540, dart intake, 1150 dom, 713 solid roller. 5000-8000rpm, 12.5-1comp
It's in a s-10 mud bogger
I must run iron heads in my class.

I have the 308's now with a very small cam, I am going full race now.
Should I build the 308's or get 345's for more power?
Need help.

[Dart Vader]

With that setup you will probably want the extra power that the 345s offer, I would go that way.

[Awesome Bill]

I hate to say this but RHS 320cc would be better than the 345 for that application or I would port your 308's for the proper set up and put some 2.3" valves in it. A 345 head is quite large and I assume you have never put it on a dyno? your not making any power at all over 7000 rpm. Feels good but your wasting your engine and valve train up around 8000 rpm. We don't even turn our BBC big chief any more than 7400 and they fall off. jmo

[4-play]

My friend has 380's on his 540 and it runs really really good. But there al. heads. I thought the 345 would work for me. I want to get all I can out of the motor.

[PRO 1]

It's one thing to make a recommendation if it really leads to superior results, but in this case it doesn't seem neccessary as the 345 heads are excellent for this application.

As for the 320 heads being better for a 540 engine than a 345, I strongly disagree. There are cases where the smaller runners might be better for a larger engine, this is not one where I feel that way.

The engine could use more compression, this can be achieved when the head swap is being done, it runs a big carb, has the Dart intake and turns 8000 rpm, and starts at 5000, that is perfect.

I am not sure where the idea that a 540 does not make power above 7000? Yours might not, but rest assured we have one here that made power well above 7000, matter of fact all the way to 8900 rpm, with Big Chiefs, we could argue for days about engine combinations. That is not the point here, bottom line is you can and should use the 345 heads on your engine.

Thanks.

Pro 1

[4-play]

what do you recommend that I do.

How do I get my compression up?

I was looking at getting a top end kit.

I still need to get the cam also.

[want-a-be]

Do the 345s. Bump the compression nearer to 14-1 or better. Call Cam-Motion for your cam selection. 1-225-926-6110 is their number. Ask for Dan. He pretty much knows what a lot of these heads flow. Have ready what you are wanting to do and the combination you're wanting to put together. I have some 540 engines out there making good power up to 8500. The track is the only true dyno. But when you approach 8000rpm you need to start paying better attention to your oiling.

Make sure you run a good rocker system. If you don't already have stud girdle and all, you might want to consider the Jessel shaft mounted rockers. They have a Budget set that when you add all you're going to buy up will not be much more expensive. They are worth the little extra $$$. It's the first $500 that's the blow...the next few $100 is easier to swallow if you can step up in quality. Mostly though this will help you on broken rocker studs and nuts.

PM me for any direct questions you might have. I'll even help you pick out the parts you need to run. I've helped a few guys here with their stuff online.

Later, Don

[lun40119]

Like me :D

[BAD67]

And me too :D;)

[Awesome Bill]

Every engine builder I have ever talked to says the 540" engine is the break when it comes to anything over 320 cc's. The 565 has the 4.6 bore so it will at least work better with the 345.

Personally I have used the 345's on a 540 and it done o.k. but nothing like it done when we put the 335 Pro 1s on it. Picked up over 4ths and 5 mph. The engine with the 345s would not run. We installed the 345 right of Brads Chevelle right onto a 565 in and injected (Rons) engine and put it in a dragster and it runs 7.50's all day. Very light car verses heavy car. Big runner smaller engine, larger engine larger runner with a light car. If someone has a 345 head making power @ 8000 rpm, I would love to see it in action.

I can see a Big Chief head doing it up there with no problem, but thats not even close to this package. If its blown, injected, NOS, turbo, it might work well, but with being Naturally aspirated, I don't see it.

Joey D runs Super Comp and had the fasted 335 headed 540 or 548 in the country. 7.20's all day. 2 years ago he went to 355's, bigger cam and a ton of work. Thinking he was going to run 7.0. DID NOT HAPPEN. Even with a cam change I think he did get a 10th at the most. He may have went a little faster but with his combination as it was, it was fast. Now he changed all this and went with the huge stuff and really did not do that well.

The point being a very light car did not pick up with a killer head package what makes you so sure this is going to work in a package like this. We all can say this or that, but his time slip will tell the story.

could be worng, but don't think so. Also, the RHS head does work very well. It is very comparable to the 325 DART head but that is aluminum. DART does not offer a 320 cc head for the big block. Why not?

So just to throw 35 cc's worth of intake runner does not really for sure make power and some cases will hurt combinations. If he had a 565-604 or so engine, yep I go for it. When comparing apples and apples, oranges don't count. Special angle heads promote better air flow and will work in higher rpm combinations, that is not the same here and the intake manifold for that combination, shaft rockers, huge push rods all factor better quality for RPM. Try that stuff with a .080 wall push rod and see what you get! Been there done that and at the least, your just spinning the engine like a blind man trying to use a tach. It don't matter.

I will be more than glad to put a 540 together. I will put a set of RHS 320 Steel heads on it, or a set of Aluminum 325 Pro 1s on it and dyno test it extensively and get out of it what I can. I will then take a set of 345 Steel heads on it and back to back dyno test it and put this to rest. We will use the same exact combination and see what happens. I can give you a little hint, It will be down on power right to 7000 rpm. At that point it may match. Why, well because with out changing the fuel curve to account for the slower air, it will not lift nowhere near as much signal for the carb. So with out a pretty slick feller like my self ajusting the fuel it will actually do worst. I will invite any one who wants to come, have the dyno calibrated and let someone else run it. You supply the OTB, (out the box heads), and I will supply the Dart block, LW crank, rods pistons and all the labor. Do we have any takers?

I will be more than glad to do this and at the same time, I will gain some added no how on changing out heads in 45 minutes. I do need a little tune up on that. Hope we can do this, it will at least get some real information out there and that will help make good choices for people to use. Any time. p.s. without wacking the heads, and assuming his are 116-119, he is not going to increase compression. Compression does not make HP, AIR AND FUEL going boom do. You can prove that from blower engines. 8-1 compression engines and stuffing it full with air and fuel will always make more power. Fuel octane for proper matched compression will do more than gas porting will any day.

[4-play]

That's some good info, thanks

[PRO 1]

"Compression does not make HP, AIR AND FUEL going boom do. You can prove that from blower engines. 8-1 compression engines and stuffing it full with air and fuel will always make more power."

I copied this statement, I found it rather interesting.. Compression does not make horsepower? Well as an engine builder, explain why, when you change an engine from 10 to 1 to 12 to 1 it makes more power???

So a NHRA Pro Stock engine should lower the compression, and they will still make the same power?

I agree that a turbo charged engine or supercharged engine makes power with out compression, however an 8 to 1 engine making 20lbs. of boost actually has a corrected compression ratio of 18.9 to 1. 8 to 1 is the static ratio, the 18.9 to 1 is dynamic ratio, so it is making power with compression, however it is being created in a different manner.

All this proves is that there are more ways to produce compression.

We know as engine builders that you can build a short block, and it can make good power with a chosen head, for example Bill chose his engine to run well centered around a 320cc runner, that works for him. However we have dozens of builders whose 540's all use 345 runner. It works for them, matching the parts, camshaft, compression, intake, carb, header diameters, rpm the engine will be run it will depend on how one wants to buld the motor.

Like i stated before, we built an engine here in the shop it was a 540 with compression, Cam Motion roller cam, Dart Big Chiefs, single four barrel, and the engine made 1137hp. We then tested it with a CFE built intake, with two carbs, it made 1200+hp. This is a engine running well above 8000 rpm, using Big Chief heads (the Pro 1 version), lots of compression, and making gobs of power. All of these are variables that as stated on this thread dont work, dont make power, and should not be used...

Now gas porting, that subject is something we could argue, but when someone is set on their ideas, you can not change their minds. I will say this, we have spent 20 years building engines, many of these in NHRA Pro Stock, we use gas porting, every NASCAR engine I have ever seen has GAS PORTS, the piston companies will be glad to explain the benefits. As for a street built, or bracket racer engine it might be a waste of money. However it is designed to push the rings against the cylinder bore to help it seal better, no matter how good you hone a bore, this is something we spent ten+ years working with stones, speeds, oils, holder, pressures, etc to refine the best way to hone a block out there. We know honing and we know gas porting as we do this in house, and it is necessary and worthwhile in any real racing application.

Thanks
Pro 1

[4-play]

so how do I change my Compression ?

[want-a-be]

enough said

[want-a-be]

pulled from the peanut gallery;)

[Awesome Bill]

Most of the time, your pistons will be 10, 20 ,30 40 cc or be a fixed configuration for a particular engine. Take the BBC. Most heads are production style and will yeild 119 cc or somewhere close to that. So we use a 44 cc dome, we loose 10-12 ccs from our head gasket and if your piston is in the hole, you will loose that also. Most pistons are factored on .005 in the hole so that will be a given. So if our engine has a 34 cc dome yeild with head gasket, you add that to your combustion chamber and then bore and stroke. You can cut the BBC heads way down, I have done 110 cc with .060 cut. I stay away from angle milling to avoid piston to valve problems if the engine is already together.

So the cheapest way is to raise your compression is 1. Cutting the heads, 2. Changing out the head gasket to maximize the quench area to around .040 3. Running a flat style valve. Other than that, you have to do this before assembly with putting the deck @ 0 4. Putting larger domed pistons in, which kill flame travel, 5, increasing stroke and bore size, 6. blowers, turbo, NOS all raise compression levels because you are craming more air and fuel in then the engine can do naturally, AS I SAID, AIR AND FUEL make power, the more air you get in, the more fuel you can introduce to make expansion.

So those are your choices. Now Most engines naturally aspirated do like 12.75 to about 14:1 compression. Any thing more, you really don't improve unless your going to run alky. Give me a well prepaired 13:1 engine with VP110 and keep it under 7500 and your going to be hard pressed to make more power with a 14 or 15 1 because at this point the engine has to work harder to compress the mixture and the end result will sometimes yeild way less. So that is what I mean about compression and power. Now if you use 15-16 as I have and made decent power, you have to run the more costly fuel so it will not self explode like a desiel. C16 is pretty common over 15 1. But if your not set up right, you won't make a dime more power than a properly set up 13/1 engine. Why, because there is only 19,000 BTU's of energy in 1 pound of racing gasoline. I am not talking about oxegineated fuel. So a BTU is a BTU. A more stable fuel has more ability to not go off before peak cylinder pressure is achieve. This gets complecated and time consuming. Give me a blower any day with alky and you will see power.

A ton of people think if your 15 to 1 or better this will make power. In some most cases you loose if your not tuned correctly People who say these things are un informed and just plain stupid. Your margine of error window gets tighter and tighter with each compression ratio you increase with. So I would rather stay wide and keep it safe when it comes to some one who is not a familiar with compression and its attributes and disavantages.

Now from pump gas 10-1 got to 13-1 with race gas, this will yeild decent power increases because of leak timing, camshafts, larger cylinder heads and having to wind it up to make power. Piston Speed causes heat, heat causes things to go off before the right time. Even the air speed in the runners with the parasetic drag creates heat. So you have to be careful with fuel and compression. That is why so many people burn their stuff down with Nitrous. They have not got a clue nor do they under stand what is going on. We make sure your well informed and teach you how to tune your own NOS racing engine when purchased from us. So I hope this clears up the peanut gallery hecklers a little so you can be aware of what happens.

[Dart Vader]

Bill, you should avoid referring to other forums members as a "peanut gallery" or as "hecklers", it is condescending and it damages your own credibility. There are a lot of people who are very knowledgable about the topics being discussed here and each of them is entitled to their opinion on a matter.

Those seeking advice on the boards here should be able to get input from various individuals and determine the best course of action based on their own judgement, and a combination of opinions.

Debate is good and healthy, it often leads to answers and knowledge gained, but name calling is silly.

[4-play]

So at 14:1 can I run 110 or something higher?

[BIG CHIEF]

So at 14:1 can I run 110 or something higher?


I would recommend C14 (114) or higher. The combustion process / flame front will be more controllable with the higher octane fuel. Let us know if you have any further questions.

Thanks,

[want-a-be]

My friend has 380's on his 540 and it runs really really good. But there al. heads. I thought the 345 would work for me. I want to get all I can out of the motor.

If you're talking about Al Neal, I doubt he is taking the 380's and welding them up til' they are smaller in runner size. You have seen what these heads will do yourself. Stick with the 380s and buy the pistons that will make the compression. Run the heads for a season then Deck them during the off season. That way they are seasoned wehn they are decked. Give them a valve job at that time also. Same reason.

Al does great work. I've talked to him a few times. He use to do the head work for the people who taught me to build a proper engine. No...my way isn't the only way. But what I do works, and stays together.

YOU WILL LIKE THESE HEADS!!!:p

[Awesome Bill]

At 14/1 you are border line for 110 and 7000 rpm. You could run into fuel issues buying it from someone you don't know and be close to the edge and hurt the engine. I can run 110 with that combination right up to 7000 rpm with no problems, but I have nock sensors and 8 egts and see if the power is o.k. We usually tell the customer to either keep the timing 2 degrees back from peak or make sure they run VP, a proven race fuel.

The C12 would be the fuel for you with no problems @ all. You could run right over 7500 rpm @ 14/1 and see fantastic power if you can make any up there. Of course, if you are a tad rich and want to kill 2 birds with one stone, run the new Q13 for your application. We just dyno tested the stuff with a 14.5/1 565 Pro Bullet engine and the fuel leaned the engine out as teted and the egts got to 1475 and I pulled the engine back. We went to 96 jets from 94 and we picked up on the average 10hp. That stuff will make power especially if you run your engine a little fat and don't know it. It will also kill it if your lean on the shifts or top end. BE CAREFUL, that stuff stinks bad and everyone will know your running oxygenated fuel!

As far as 114 fuel, that will kill your engine dead if you don't run over 8000 rpm. That fuel is not recommended for your application. Just go to the VP site, don't believe me here. We dynoed a small block 434 with that stuff and it did not even want to run down low as well as the C12 did. I did do o.k. up around 8000 but made no power @ all more and the owner of the engine knows now his engine only makes power to 7000 rpm. For years, he blew up engines because he was told by his engine builder to turn that thing 8200 rpm. He broke so many engines he started his own recycling business It does burn a little faster but you need something more like 14.5:1 to 15.5:1 to maximize that fuel with the rpm. I have used that in NOS applications under 300hp with engines and worked quite well as long as the compression was under 14:1. The specific is under .695 and is only for high rpm engines. The fuel is very stable up there and thats what it is for. It is very fast burning up there and will yield proper power for higher rpm and higher compression engines like comp. engines.

Second to tuning, you should always know for sure what your compression is @ a starting point and use the properly suggested fuel for that combination and RPM you are running. Opinions mean nothing, mine or anyones. If you not sure, go to the VP site and check it out.

[Awesome Bill]

Cool, less I have to type.

[4-play]

I think i'm going with the 345's and a dart intake. What's cam should I run with this setup. 5000-8000rpm?

[Awesome Bill]

I would go with the Dart Article all the way! That way your going to have what you know you will get. No guess work. jmo

[4-play]

I would go with the Dart Article all the way! That way your going to have what you know you will get. No guess work. jmo

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Thanks for the input.