400 sbc build

[hurst1979olds]

my friend is building a 400 right now

his heads http://www.summitracing.com/parts/AFR-1110

cam http://m.summitracing.com/parts/HRS-112591-08S

5.7 rods with these pistons http://m.summitracing.com/parts/UEM-KB127-STD

I would never use a set of heads with so much spring pressure on a flat tappet cam. 225 closed pressure/600 open pressure! Let alone heads that flow that good with such a small cam. When he complains about the engine and how it isnt what its suppose to be, youll know why.

 

[454cutlass]

thanks for the info i will let him know. been going back and forth on cams for a while now. any help would be greatful.

if got a solid cam or solid rollers would they need constant adjustment? doesnt want to spend the money on hydrolic roller

 

[chevy2480]

thanks for the info i will let him know. been going back and forth on cams for a while now. any help would be greatful.

if got a solid cam or solid rollers would they need constant adjustment? doesnt want to spend the money on hydrolic roller

I run afr 220 heads with solid roller. I also run a rocker arm stud girdle this along with the roller rocker poly locks. Limits the amount of adjustment if any i have done.Also with those piston he wants to run make sure he has the piston to valve clearance checked those heads have a big 2.10 intake valve. Unless he plans on building a almost full out race motor maybe he might want to consider a smaller cc head.

 

[chevy2480]

my friend is building a 400 right now

his heads http://www.summitracing.com/parts/AFR-1110

cam http://m.summitracing.com/parts/HRS-112591-08S

5.7 rods with these pistons http://m.summitracing.com/parts/UEM-KB127-STD

I would never use a set of heads with so much spring pressure on a flat tappet cam. 225 closed pressure/600 open pressure! Let alone heads that flow that good with such a small cam. When he complains about the engine and how it isnt what its suppose to be, youll know why.

Cant believe i missed that. Lol

 

[hurst1979olds]

my friend is building a 400 right now

his heads http://www.summitracing.com/parts/AFR-1110

cam http://m.summitracing.com/parts/HRS-112591-08S

5.7 rods with these pistons http://m.summitracing.com/parts/UEM-KB127-STD

I would never use a set of heads with so much spring pressure on a flat tappet cam. 225 closed pressure/600 open pressure! Let alone heads that flow that good with such a small cam. When he complains about the engine and how it isnt what its suppose to be, youll know why.

Cant believe i missed that. Lol

I was building a 383 with 195cc AFR heads today for a customer. I looked in the paperwork and it said says all their spring presures for all theory springs. 225!!! That's crazy pressure.

 

[454cutlass]

after some more looking he came up with cam... http://m.summitracing.com/parts/HRS-111153-08S

might go down to a machine shop and talk to them about the build.

again thanks for you help

 

[crotchss]

87ttop if you use the vortecs they will work great for a zippy street/strip engine, make sure you use dished pistons with that 64cc chambered head. Also don't forget to get the valve guide height cut down to handle more than .480 lift, just swapping to a better spring isn't all that's needed. What intake are you planning to run? The vortecs have their own dedicated intake pattern, as I'm sure you know, or you can drill the heads for an old school intake pattern. I have done this a few times with good success. I'll try to post a video of what the XE274 cam sounds like in a 10:1 406. I've got polished beam stock 350 rods in that one with ARP bolts and didn't have to clearance the block or run a small base cam.

 

[crotchss]

454cutlass, is your friend building a full out race motor or limited street car? If he's wanting more of a street car I think he would be happier with a set of AFR 195's or at most AFR 210's. That much of a cylinder head needs to be on a big inch smallblock or a high winding radical one with higher compression. I'm very pleased with my 210's and the power they made with my set-up.

 

[454cutlass]

it will be a street car with limited track runs. he is trying to build it big as possable with in his budget. he is set on using thoes heads for some reason. im just trying to help him out. i will probably be helping him build it so dont want it to fail or be to out of wack. we have each built normal and slightly built motors but nothing all out like this. here is his full car build if interrested http://www.necamaro-firebird.org/forums/viewtopic.php?f=34&t=4624

 

[CHRIS.O]

Yea you should probably point him towards a different build. Those heads are kind of overkill for what a 400 is going to support with stock internals. Unless he is going through the bottom end and replacing with aftermarket stuff. Those heads are what you would see on a solid roller 434 pushing 600hp. No reason to spend a bunch of extra money when his goal may just be a 400-450hp street strip engine. With the large runners hes going to be spinning high RPM's to make useable power. Not ideal for something that your gonna drive around in my opinion.