I recently bought a rebuilt 406 and coincidentally it has the same exact roller cam installed that I run in my 355. its a comp XR270hr-10 (270-276 218-224 cam) Its new and never been run.

I am looking for advice on whether this cam would be a good upgrade for the additional power, better firing order for bearing life and cooling and slightly more aggressive sound. I feel like the comp cam will be more tame and feel smaller in the 406 than it does now in my 355.

https://www.summitracing.com/parts/sum-1223#overview

Summit suggests a 2500+ stall but I assume thats in a 350 right? wouldn't the power curve start like 500 rpm lower in a 406? I have a 1800-2200 stall in my new trans.

I mainly want the torque as this car is street driven only but I do like to do spirited driving on country roads. will the slightly stronger lower end on the comp cam be more noticeable for my use?

Here is what the dyno software is showing for each with my setup and 1.6 rockers.

 

I suggest you call Mike Jones, or go to his website and complete his online cam selection form. He will provide you the BEST cam for the operating parameters, engine, etc that you enter into the form. Otherwise....asking for a cam recommendation on a forum thread is about as useless a question possible. Its about as useless as "what's the best engine oil" threads. What you will typically get is recommendations on cams much LARGER than you are wanting. My experience is that most forum members, on multiple forums....ALWAYS perceive the only good cam is a race car cam.....which is the WRONG cam for a street driven car.

But then again...as usual.....I have come to realize my idea of many things related to Corvettes is not the mainstream. You need to find out which group you fit into.

 

I actually agree mostly with what you are saying here with the opinions usually going extreme regardless of OPs goals.
But at the same time there are a lot of guys here who have built many engines or swapped multiple cams too. and opinions are opinions.. I can hear them without being offended because I dont share them. Ive found out multiple times some of those opinions ive not agreed with at first had more value later just as often as finding the opposite in my experiences.

I may just stick with the 270 cam as it does have impressive numbers and this "budget swap" has been quickly climbing in cost with all the "might as well while im in there" changes... The pistons for example, I found my block is decked and have 30cc dished pistons so I have convinced myself that its worth it to go to the 18cc version of the same pistons that are in there now...(takes my compression from 9.1-9.2 to 10:1) that leads to another dilemma of whether I bother to have it all rebalanced when much of what ive read from the experts like David Vizard tells me for my application and rpm range the balance is not necessary yet the internet peeps say otherwise. I know it cant hurt and can help especially if its way out. I also know the 18cc pistons are close to the same weight and I could weight and remove some weight myself to match the old pistons as I see the old ones have holes drilled into them I assume for balance.

I just dont want to throw this together and get it in the car only to feel it wasnt worth the upgrade vs what it could have been with these changes.

 

Buying and driving my C6 Corvette has proven to me that I have always been right about cam selection, torque etc.....no matter what the mob says. This is my real life experience, and it identifies the important points and facts about this.

The first build on my C3 406, (the beginning of a multi year disaster that I documented, and sure you have read)...was cammed with a 224 cam,....on purpose, as Mike Jones selected, to provide maximum torque at lower RPM's. It also comes with the benefit of a better idle vacuum, carb tunability, etc. Even with all its problems, that engine was everything I wanted in pushing me back in the seat with every gear shift......WITHOUT resorting to taking it to 5500 RPM to provide the fun I wanted. It did it at 3000-4000 RPM. IMO thats a win win.

The second rebuild...by Mark Jones, include a cam with 10 degrees more duration, a 230 cam. Frankly and honestly, with that cam, the car STILL accelerated very well within my shift limits, and of course, produced way more top speed...I suppose. But it came with a very rough idle, low and fluctuating idle vacuum. Did the car accelerate the same with this cam as the 224 cam??? Its a little difficult for me to measure that because there was a year in between driving the car, so its not a fair butt feel comparison. I will say it still accelerated well. Factually, and theoretically......I had to have less torque between idle and 3000 RPM with this cam, and therefore it had to accelerate less between idle and 3000 RPM.

Now.....the 2006 C6 Corvette for comparison, and the experience that backs up my points. This is a reported factory 400 ft lb / 400 HP LS2 engine, fuel injection, computers, sensors, etc. Its a manual transmission with a similar rear end to my C3 (C3 - 355 / C6 - 342). I can tell you without question that accelerating the C6 from idle to 3000 RPM is LESS than my C3 with either cam. To make that clear.....my C3, with either build of the 406 OUT ACCELERATED by 2006 C6 when shifting at 3000 RPM. No questions about it. And because of that, my C3 is MORE FUN than the C6 to drive.

Now....when I let the RPM build to 5500, which I have done ONE TIME, in the C6, ........the car becomes a missile, which on the roads and streets I drive in western PA, makes it irresponsible and dangerous. The car accelerates very quickly to speeds that are unsafe and irresponsible. I have no desire to jeopardize others lives, nor mine, because I want to drive like I am on a race track.

So, this makes my point very clear to me, even if MOST do NOT agree with me. My C3, with a 400 SBC well built, with a cam Mike Jones specifically spec'd at low duration, provides MAXIMUM fun from 0-60 mph WITHOUT resorting to 5000 RPM shift points. Just like a Harley.

Not sure why this continues to be something most don't comprehend. When I talked with Mike Jones about this, he fully understood it, and supported my point. And yes,.....a low duration cam does not provide as high HP....but HP is a calculation, and for many, having the biggest HP number is what matters. On a track it matters. In a race it matters. But in terms of real life, on the street fun,....HP is just a number. Bottom line....the highest torque within the real life RPM range you drive the car.....is the best way to cam an engine. If you want to run an engine to 5000 in every gear......cam it for that. I personally think an engine is pathetic if it takes 5000 RPM to accelerate that car. And the mob hates it when I call their engines pathetic.

As you know, my new build, which I am building myself from a CNC Motorsports shorblock.....is going to be cammed with a 220/224 Mike Jones cam......which Mike ensures me will provide me the MOST torque I can get with this engine,.....between idle and 5000 RPM, especially between idle and 3000 RPM. I believe him, and looking forward to it. Yes....and he told me this,....it will produce less total HP. So what. I don't care about HP or maximum speed, and I am quite sure that even with this small cam, this car easily could exceed 120 mph.....which will never happen with me in it. But, I am looking for to a very reliable, strong engine, that will push me back in the seat of the car when I push the pedal down.......all under 5000 RPM, in fact, shifting at 3000 RPM.

Sorry for the long post.....I don't expect many to agree, with the exception of the few. Obviously...you are going to make your own choices. I have said my piece....and I am not bickering any more about it.

 

Well I think theres a point here where theres so much torque that I wont be utilizing it or will likely break things trying to do so..

My car is an auto with OD and 3.55 gears. I see the 218 cam does give me better low end power than the 224 cam but I am actually looking for a little bit of that hot rod sound to go along with the flashy c3 looks.. Since the rpm range shifts down 500rpms or so with the 406 im thinking the 224 cam which is a bit more efficient in utilizing the larger ported heads and 1 7/8 header side pipes might be the better option here for me as it still gives much more torque than my current engine while providing like 50 additional hp for when I do open it up on a long country rd.

At the same time im not interested in running a higher rpm stall than what I have now so if the 224 cam is going to have issues in OD on the highway there than I would like some insight on that now if I can get it.

 

Yeah, know there can be too much torque for the tires.....but my cam is nowhere near that point. Will I be able to floor the gas pedal? No.....but I don't do that, never will. And my car accelerating from idle to 3000 RPM sounds awesome. These subtle differences do not change those attributes at all. My 77 with the small cams sounds good at idle, and at 3000 RPM, and in now way is a "sacrifice". I think its perfect. The suggestion that my cam / torque concept equates to a "Cadillac" mentality is absolute nonsense. Conversely, the idea of creating a cam sound (i.e. rough idle) to create an "image" of performance, and sacrifice real low end performance, is something I don't do. Mike Jones told me guys call him up and say....I want a rough idle, race car sound with a cam.......no matter what the sacrifice is in performance. I guess thats a choice.....but not my kind of choice. I am just an honest guy, not pretending to be something I am not, .....and not trying to build a car/ engine that way.

Anyways...enough said.

 

yeah if you read anything I said in either one of my threads on this you would have read that im not looking to sacrifice benefical performance for sound but if I can get a little of both with a step up in cam size in a larger displacement engine vs what im getting with the same cam now in a smaller 355 than thats something im willling to do. Im not talking about throwing a thumpr or huge lopey cam in here.

My opinion and priorities are mine just as yours are yours but
looks and sound do in fact factor in... As someone with a bright orange C3 with cosmetically upgraded wheels and such, and a Harley, marketing and Image does factor into your choices at some level as well regardless of if you recognize it or not. To me many stock c3s are slow underpowered cars that have been pretending to be something they are not for a long time but I'm not ridiculing anyone about it.

 

Could you rerun those two cams and don't add the 4 degrees. Because most cams are ground with the advance and you dial them in straight up.

Please post the sims correct

Thanks

 

im not sure im understanding? if the 4 degrees is ground in and im installing the dot to dot am I not installing with those 4 degrees advance? EDIT I see now, I didnt add that 4 degrees the number autopopulated when I filled in the cam specs but ill change it. maybe the default cam had it set there before I created new files.

 

ok Ive changed it. honestly I dont know how it got changed to 4 degrees. This appears to have improved the hp numbers a bit.

 

I think they are both going to run well and make good power in a 400.
The 214 looks to be 6-15# TQ & HP stronger under 4000.
The 224 looks stronger over 4000.
I think both are pretty mild and will not have a lot of idle lope.
The 224 will have slightly more. The same cam will feel smaller in the 400 like you said. 500 less rpms for peak etc. But way more TQ below 4000, like 50# worth vs the 350.
Even going to the bigger cam, it will still feel somewhat milder because the bottom end TQ tends to flatten the TQ curve by lifting up the bottom.
Both should have good idle vacuum. 15" +
50 cubes makes a big difference. It is going to feel way stronger no matter what.
I like the 224 cam. It's about as mild as a 425HP ZZ383 cam. But it'll sound pretty good. Drop the idle rpm 50-100 if you want more lope at idle. You know what the one cam sounds like in your 350, it will sound milder in a 400.

But please don't believe the sims outright #s. They look a little high. The differences between the two runs look correct tho.
I believe the 214 will make peak power at or below 5000, not 5500, in a 400. The 224 should be like 500 higher.

 

That summit cam is pretty mild for a 406. I don’t think a 2200 rpm stall would be a problem. You can run around 218 degrees of duration on a stock stall converter.

 

I completely understand the dyno software numbers are hypothetical and optimistic but still a good mathmatical comparision between the two.

 

How do you feel about this Erson cam??

 

Now instead of using the cam file. Input the same lift figures for the summit cam changing it from 110 to a 112 lobe center angle for less overlap by inputting

Ivo of 31 and ivc of 65. Evo of 71.5 and evc of 27.5

The amount of softer camshafts produced makes it worth going to billet steel with a sleeved on dizzy gear. Using something like comp cams extreme series lobes for more power and increased volume metric efficiency. Area under the curve. You are basically increasing the. 200 duration numbers by having steeper ramps on the lobes

I have custom cams that I had made for my 383 , 396 and 427 SBC's from the CC lobe pdf's pages. I also played with the retarding of the cam and found the widest TQ curve average highest was at 4 degrees retarded

 

Torqued Off has a big advantage over you with heads. Higher cfm flowing heads require less cam duration to make the same amount of power as a lower cfm flowing head.

How AFR heads make higher flow is. Bigger diameter valves and seats with smaller diameter valve stems which open up the port flow. 2.08 intake has lots more area than. 2.02 valves no matter how well it's been ported

400 ci is harder to fill than 350 ci. Is why the sim is showing low Volumetric efficiency

 

the software does not allow me to have 112 as the lobe center angle with those numbers. it changes it to 109.5 each time

 

where can I find the rest of the timing events on this cam to try it in my software. It seems a bit big for my application but I wont know till I simulate it.

 

So input the 112 lc valve event numbers and run it with the cam installed straight up zero, -2, and-4 degrees and post the sim that looks the best to you.

My 383 and 396 got the 112 LC which was less reversion and higher BSFC which translates to higher MPG

 

For some reason none of them really do much with this combo unless im doing something wrong. It does make it a bit more peaky on hp but at a loss of torque and hp in the lower driving range which isnt really what im looking for. If I had a stick maybe..