400 sbc build

[rich weyand]

I ran the simulations on a 400....

 

[85c10owner]

I ran the simulations on a 400....

No offence Rich but I don't trust simulations. I am going off of actual builders dyno sheets I've seen of different forums.

 

[rich weyand]

You've got actual builder's dyno sheets on both the 12-212-2 and 12-235-2 cams? Wow.

 

[85c10owner]

You've got actual builder's dyno sheets on both the 12-212-2 and 12-235-2 cams? Wow.

No Rich, with similar grinds. Get real. I've been around the block enough times to know how the camshaft is going to act. It's not rocket science.

 

[rich weyand]

OK, so all I said was that, according to Comp Cams own information on their products, he was leaving a lot of torque on the table with the 12-212-2 grind, compared to, say, the 12-235-2 grind.

And this was wrong how?

You've argued that the 12-212-2 would generate plenty of torque. You've argued that a 400 will act much differently with a specific cam than a 350. And you've said that your authority wasn't some ****** simulation but real honest to god dyno sheets of real builds. Except then it wasn't, it's just your gut-feel hand-wavy seat-of-the-pants impression because you've been around the block a lot and all this is simple.

And all of this in furtherance of what argument? I don't know. The 12-235-2 will deliver more torque, sooner, and hold it across the power band, than the 12-212-2 in an SBC 400 according to the manufacturer of both cams. I'll stick with that.

 

[85c10owner]

OK, so all I said was that, according to Comp Cams own information on their products, he was leaving a lot of torque on the table with the 12-212-2 grind, compared to, say, the 12-235-2 grind.

And this was wrong how?

You've argued that the 12-212-2 would generate plenty of torque. You've argued that a 400 will act much differently with a specific cam than a 350. And you've said that your authority wasn't some ****** simulation but real honest to god dyno sheets of real builds. Except then it wasn't, it's just your gut-feel hand-wavy seat-of-the-pants impression because you've been around the block a lot and all this is simple.

And all of this in furtherance of what argument? I don't know. The 12-235-2 will deliver more torque, sooner, and hold it across the power band, than the 12-212-2 in an SBC 400 according to the manufacturer of both cams. I'll stick with that.

LOl Ok Rich. You cling to your simulations and I`ll stick to the real world.

My argument from the get go was that you claimed the 280 magnum, sorry dont know grind numbers off the top of my head like you do, is not a torque monster. I know for a fact that it is. I didnt learn that from a computer simulator I learned it from hearing first hand info and riding in the damn car. Granted it wasnt a 400 but it was a 383 with the same stroke so Im going to call it close enough. I dont know what your actual experience is Rich because all I see from you is computer simulations but I have been doing this almost 30yrs without a simulation. Yeah, Ive made my share of mistake and mismatched parts but after a while you get to know what works and what doesnt.

Again, none of this matters Rich because as Ive said before, WHERE IS THE OP? Not in here so its all for not.

 

[deano1977]

ok guys sorry ive been away from the computer. but I guess I left out some info I will be doing a 2300-2500 stall as well its a th350 trans and I have been looking into getting rid of my iron heads. ove been looking into some aluminum 202/160 64cc heads and from what ive seen it will put my compression down to 8.5:1 but people on other fourms say I can run pump gas still and that's all I want lol. and what im doing with the truck is I want to hAve a fun street truck and go track race it. now for gear im still not sure on that I was thinking 3.73 if u guys need more info let me know

 

[crazy4offroad]

What was the old saying, horsepower sells cars, torque wins races. Some people confuse horsepower with torque and there's a big difference. The dyno don't lie, and when that torque line is nearly nailed from the low end all the way through the powerband THAT is where you want to be. What kind of racing are you planning on, 1/8 or 1/4 mile? What size tire? Most people like 4.10s for the 1/8 but something taller for the 1/4 like 3.73 or even 3.42 depending on tire. For the 1/4 you want to still have some climb at the other end but the 1/8 you don't want to leave too much on the table. It also depends on what class you're wanting to race, which is often tied to how much vacuum you can pull, which is also tied to valve overlap, determined by the grind and LSA.

 

[deano1977]

this is a fun truck no classes more like test and tune that's about it. like I said I already have that cam and just going to do a stock rebuild and im going to do fuel injection as well im going to keep it a 28 tall tire as well

 

[crazy4offroad]

OK cool. Based on what you said, around 2500 stall, maxxing out at 6000, these would be your speeds per gear. 4.10 gears on the left, 3.73 on the right. You can tinker with the numbers here and figure speeds at different shift points...
http://www.grimmjeeper.com/gears.html

 

[deano1977]

I think 373 will be the one I do. Ok so here is what I've been tossing around I've recently found a fuel injection kit that can handle boost for a relatively reasonable price how much boost do u guys think my 400 stock bottom end will take I was thinking 7-8 psi but unsure

 

[rich weyand]

The torquiest engine GM ever put a TH350 on was 410 lbft. So you need to seriously build that trans or go to a TH400 to keep from littering the pavement with lots of little parts.

 

[rich weyand]

LOl Ok Rich. You cling to your simulations and I`ll stick to the real world.

My argument from the get go was that you claimed the 280 magnum, sorry dont know grind numbers off the top of my head like you do, is not a torque monster. I know for a fact that it is. I didnt learn that from a computer simulator I learned it from hearing first hand info and riding in the damn car. Granted it wasnt a 400 but it was a 383 with the same stroke so Im going to call it close enough. I dont know what your actual experience is Rich because all I see from you is computer simulations but I have been doing this almost 30yrs without a simulation. Yeah, Ive made my share of mistake and mismatched parts but after a while you get to know what works and what doesnt.

I still don't see how you compare two cams by riding behind only one of them, even if you have been building engines since you were 10 years old.

 

[85c10owner]

I still don't see how you compare two cams by riding behind only one of them, even if you have been building engines since you were 10 years old.

Actually Rich I was 13yrs old when I worked on my first car. A older friend had a 1969 camaro and had just put in a very mild 383 and couldn't keep a tranny behind it. I cut my teeth helping him pull the tranny and worked on his car u til I got my own a few years later.

You claimed the 280 magnum isn't a torque cam and I claim from actual experiences that is it. I wasn't riding in a computer simulation at the time Rich.

I'm done with you and your desire to have a pissing match. I am us ub scribing and won't be checking back in to see what kind of witty comment you reply with.

 

[rich weyand]

For the OP:

To summarize the discussion, such as it was, with 85C10owner.

The 12-212-2 is a performance cam that has nice performance characteristics. I never disagreed.

If you want a "torque monster", the 12-235-2 cam has more torque than the 12-212-2, according to the manufacturer.

If you want to do racing, you need to be more specific about what kind of racing, as the cam choice will be driven by that choice. 1/8 mile stoplight to stoplight stuff is going to favor the biggest torque down low, particularly in getting a truck moving. Different choice of races makes for different choices in cams.

The TH350 is your weakest link right now. You put 450+ ftlbs through a 2300 rpm stall converter on a stock TH350, and the tranny won't last long doing serious launches. You can either beef up the TH350 by replacing the known weak parts, get a new/rebuilt TH350 where all that was done for you , or go to a TH400.