Planning summer small block build

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Obwonkonobe

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mine is 14 cc dish, 63cc heads .005 in the hole and .041 gasket.. it can be done but that is not a home built engine
Yea im starting to see a few ways to get around it a little, could I still run 87 on 9.5? Or should I step it up to 91
 

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Yea im starting to see a few ways to get around it a little, could I still run 87 on 9.5? Or should I step it up to 91

well if you havent decided on heads yet you could end up with a set of aluminium then you can do 10+...used aluming can be the same price as used Vortecs after machne work.. keep your eyes open.
 

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Heres what I was told when looking for a cam for a 400... The rpm ranges you see listed in the spec are based on 350 ci, a larger cu makes the cam milder so when looking at the rpm ranges subtract 500 rpm for the 400 and that will be your rpm band. I put a 214/224 @.050 duration cam in my truck with a 350, my 406 has a 234/244 @.050 in the vette and it pulls nice all the way to 6k rpm but it has a 3k stall and is lighter than these trucks.
I've wondered about RPM ranges, some say they aren't very accurate. Someone told me to look at a 4.3 Converter. I stil get confused about these things.
That sounds fun. I just did a compression calculator assuming stock bore and stroke, 64cc vortecs, 12.5cc dish pistons, and a .041 compressed gasket thickness and il be squeezing 10.6! Is there any way I could bump it down a point? Id be open to running different heads with larger 76cc chambers, id get to keep my intake too. Are there any good 76cc castings that i could look for?
You could try backing off the timing a bit, and cam selection will also make a difference.
Yea im starting to see a few ways to get around it a little, could I still run 87 on 9.5? Or should I step it up to 91
I run my truck on 87 and it's 9.5:1
 

Obwonkonobe

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I run my truck on 87 and it's 9.5:

That makes me feel a lot better!

You could try backing off the timing a bit, and cam selection will also make a difference.

What chararistics should I look for in a cam to avoid detonation?
 

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That makes me feel a lot better!



What chararistics should I look for in a cam to avoid detonation?
If you had two almost identical engines the only difference being camshaft profile, one that has no overlap and one that a lot of overlap. Overlap is when both the intake and exhaust valve are open at the same time and it gives it that Lopey thudding sound (the sound that makes me all warm and fuzzy inside.)

The first engine sense it has no overlap isn’t going to let the air out until the has cylced and the exhaust valve opens. The second engine with all that overlap won’t leave quite as much air in the cylinder therefore the compression will be less because of less air in the cylinder. Be warned with more overlap the vacuum will be less and that will affect the power brakes.
Engine masters has some good stuff on cams. http://www.badasscars.com/index.cfm/page/ptype=product/product_id=68/prd68.htm This explains much better.
 

Obwonkonobe

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If you had two almost identical engines the only difference being camshaft profile, one that has no overlap and one that a lot of overlap. Overlap is when both the intake and exhaust valve are open at the same time and it gives it that Lopey thudding sound (the sound that makes me all warm and fuzzy inside.)

The first engine sense it has no overlap isn’t going to let the air out until the has cylced and the exhaust valve opens. The second engine with all that overlap won’t leave quite as much air in the cylinder therefore the compression will be less because of less air in the cylinder. Be warned with more overlap the vacuum will be less and that will affect the power brakes.
Engine masters has some good stuff on cams. http://www.badasscars.com/index.cfm/page/ptype=product/product_id=68/prd68.htm This explains much better.
Good explanation and good read, thanks!
 

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Google static vs. dynamic compression ratio.

Being a heavy truck and your want to run a low stall converter you don't want a cam with much overlap. You'll need all the low end torque you can get.
 

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I need to rebuild my engine.

How much money do you have?

A little.

You don't want to go fast then.

Yes I want to go fast.

Then you need more money.

But I need torque too.

Are you pulling a trailer?

No, mudding and rock climbing.

Do you own a bank?

No.

Then you need to rob one.
 

Obwonkonobe

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I need to rebuild my engine.

How much money do you have?

A little.

You don't want to go fast then.

Yes I want to go fast.

Then you need more money.

But I need torque too.

Are you pulling a trailer?

No, mudding and rock climbing.

Do you own a bank?

No.

Then you need to rob one.
Haha yea pretty much, I'm hoping that by starting early and just buying parts as I go over the months, I spend a little more, go slow, and do it right, no mudding here though, I tried my hand and dug in past my axle once..

Thanks for the bearing recommendation too, il check them out
 

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I need to rebuild my engine.

How much money do you have?

A little.

You don't want to go fast then.

Yes I want to go fast.

Then you need more money.

But I need torque too.

Are you pulling a trailer?

No, mudding and rock climbing.

Do you own a bank?

No.

Then you need to rob one.
True
 

Rusty Nail

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You should get bigger displacement and little more compression. Retro roller cams are going to be the roller cam option. Look at the Comp Cams Xtreme 4x4 cams, something from about 600-1000 RPM maybe 1200, http://www.camquest.com/.
http://www.hotrod.com/articles/ccrp-1112-406ci-small-block-chevy/.

So i'm readin this thread right? Well I wasn't gonna say nothin until I got to Iowan's post up there.

Hey dude, please , please tell the class how longer rods equal more cubic inches and compression...?
Inquiring minds want to know!
(they do neither of those)
The only change is dwell.

Outside of that -OP, I believe that a new oil pump is a MUST given the chance. They are super cheap and there is no reason in your scenario to buy anything besides a Melling M55.

400 SBC siamese cylinders and Vortex heads + steam holes?
I do not know what that = but I see a flag on the field there.

There is also no good reason to run 5.65" rods though besides the fact that you MAY have to buy new pistons and then you WILL be forced to balance the rotating assembly. But there is also no good reason not to anyway and it's like changing an oil pump given the opportunity :imo:
400 blocks are special enough that it's worth it.

Soooo if you buy new rods OR use some 5.7 rods you got laying around, they'll need "rebuilt" anyway but at what cost vs. NEW rods to end up with stock 5.7 rods?? **** man, if you're gonna get new rods then you might as well get 6" rods and then YOU ARE buying new pistons.

It's a lot to think about and the amount of money you are willing to spend WILL answer many questions.

Deck the block only as much as you need to depending on the rods and pistons you plan to use to end up with a nice squish.

I run '77 bearings.

An SBC 400 makes torque without trying but there is that pesky overheat thing with the cylinder heads I keep hearing about. My machinist was telling me not to look past the fact that 400s make that gob of torque at 8.2:1 compression and combined with the whole siamese cylinder heads and the overheating thing with the steam holes that I REALLY DON'T want to push my static CR too high ESPECIALLY in a daily driven street truck because the ends don't justify the risk of the means.

My 2 cents.

Doowutchalike and i'll holler bout 'Merica! :patriot:

What did you figure out @Iowan? Longer rods don't move the piston any higher in the bore, they get shorter to compensate. The pin height changes in the piston ...

You must be registered for see images attach
 
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Obwonkonobe

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So i'm readin this thread right? Well I wasn't gonna say nothin until I got to Iowan's post up there.

Hey dude, please , please tell the class how longer rods equal more cubic inches and compression...?
Inquiring minds want to know!
(they do neither of those)
The only change is dwell.

Outside of that -OP, I believe that a new oil pump is a MUST given the chance. They are super cheap and there is no reason in your scenario to buy anything besides a Melling M55.

400 SBC siamese cylinders and Vortex heads + steam holes?
I do not know what that = but I see a flag on the field there.

There is also no good reason to run 5.65" rods though besides the fact that you MAY have to buy new pistons and then you WILL be forced to balance the rotating assembly. But there is also no good reason not to anyway and it's like changing an oil pump given the opportunity :imo:
400 blocks are special enough that it's worth it.

Soooo if you buy new rods OR use some 5.7 rods you got laying around, they'll need "rebuilt" anyway but at what cost vs. NEW rods to end up with stock 5.7 rods?? **** man, if you're gonna get new rods then you might as well get 6" rods and then YOU ARE buying new pistons.

It's a lot to think about and the amount of money you are willing to spend WILL answer many questions.

Deck the block only as much as you need to depending on the rods and pistons you plan to use to end up with a nice squish.

I run '77 bearings.

An SBC 400 makes torque without trying but there is that pesky overheat thing with the cylinder heads I keep hearing about. My machinist was telling me not to look past the fact that 400s make that gob of torque at 8.2:1 compression and combined with the whole siamese cylinder heads and the overheating thing with the steam holes that I REALLY DON'T want to push my static CR too high ESPECIALLY in a daily driven street truck because the ends don't justify the risk of the means.

My 2 cents.

Doowutchalike and i'll holler bout 'Merica! :patriot:

What did you figure out @Iowan? Longer rods don't move the piston any higher in the bore, they get shorter to compensate. The pin height changes in the piston ...

You must be registered for see images attach

Thanks for the advice, il defiantly get a new oil pump, didn't eve, think about it. And il be honest, I thought longer rods and shorter pistons would put the piston down deeper in the hole, but niw that you say that it makes sence that the only thing affected is dwell time. Although I'm not sure how its affected or what i stand to gain by more or less.

Il lool at 77 bearings too, ive got a little list put together of recomended companies and upgrades to do, they'll go on
 

Iowan

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So i'm readin this thread right? Well I wasn't gonna say nothin until I got to Iowan's post up there.

Hey dude, please , please tell the class how longer rods equal more cubic inches and compression...?
Inquiring minds want to know!
(they do neither of those)
The only change is dwell.

Outside of that -OP, I believe that a new oil pump is a MUST given the chance. They are super cheap and there is no reason in your scenario to buy anything besides a Melling M55.

400 SBC siamese cylinders and Vortex heads + steam holes?
I do not know what that = but I see a flag on the field there.

There is also no good reason to run 5.65" rods though besides the fact that you MAY have to buy new pistons and then you WILL be forced to balance the rotating assembly. But there is also no good reason not to anyway and it's like changing an oil pump given the opportunity :imo:
400 blocks are special enough that it's worth it.

Soooo if you buy new rods OR use some 5.7 rods you got laying around, they'll need "rebuilt" anyway but at what cost vs. NEW rods to end up with stock 5.7 rods?? **** man, if you're gonna get new rods then you might as well get 6" rods and then YOU ARE buying new pistons.

It's a lot to think about and the amount of money you are willing to spend WILL answer many questions.

Deck the block only as much as you need to depending on the rods and pistons you plan to use to end up with a nice squish.

I run '77 bearings.

An SBC 400 makes torque without trying but there is that pesky overheat thing with the cylinder heads I keep hearing about. My machinist was telling me not to look past the fact that 400s make that gob of torque at 8.2:1 compression and combined with the whole siamese cylinder heads and the overheating thing with the steam holes that I REALLY DON'T want to push my static CR too high ESPECIALLY in a daily driven street truck because the ends don't justify the risk of the means.

My 2 cents.

Doowutchalike and i'll holler bout 'Merica! :patriot:

What did you figure out @Iowan? Longer rods don't move the piston any higher in the bore, they get shorter to compensate. The pin height changes in the piston ...

You must be registered for see images attach
Thanks for the call out. I was wrong. Wasnt trying to be a teacher just trying to explain things and help. I'll make sure to check my facts.
 

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