Thread: Next season's upgrades

Tweet

What do you guys think?? Engine is a 505 BBC stroker. Currently have GM 291 rect. port heads. I like them, but think the 327cc intake runners are killing a lot of my lower rpm performance. Dont get me wrong, it pulls nicely, but I think I could do lots better. I have a set of #215 oval port GM closed chamber heads, stock. I want to use them because of the small chambers, as I have flat top pistons, and Im not changing them this time around. So, heads will be done over with 2.25/1.88 valves, unshrouded and short side radius worked, good valve job, all the usual stuff. With the 100cc chambers, I will stay at or close to my current 10/1 c/r. Im thinking of going back to a Team G intake, currently have RPM AirGap. Not sure of this yet however. Carb will be a Pro Systems custom built 950HP. The cam I now have (solid roller) is 255/259 @ .050, 110 lsa, 104 icl. The reason for only 4* between int/exh is that the 291 heads have been milled quite a bit, and my block is decked to .005, so I have exhaust valve clearance issues. The cam designer did the cam with this in mind. That will no longer be a problem with the other heads, so Im going with a solid roller, 253/263, .668, on a 108. Im pulling the TH400 for a rebuild, and when it goes back in, it will be with a new converter from Dynamic Converters. Custom built, 3200 brake stall, 4500 flash stall. Lets see, I think that about covers it for now. Heads are going to the shop this week, as soon as the springs that I have ordered to go with the cam, arrive.

Originally Posted by 1JohnnyO

What do you guys think?? Engine is a 505 BBC stroker. Currently have GM 291 rect. port heads. I like them, but think the 327cc intake runners are killing a lot of my lower rpm performance. Dont get me wrong, it pulls nicely, but I think I could do lots better. I have a set of #215 oval port GM closed chamber heads, stock. I want to use them because of the small chambers, as I have flat top pistons, and Im not changing them this time around. So, heads will be done over with 2.25/1.88 valves, unshrouded and short side radius worked, good valve job, all the usual stuff. With the 100cc chambers, I will stay at or close to my current 10/1 c/r. Im thinking of going back to a Team G intake, currently have RPM AirGap. Not sure of this yet however. Carb will be a Pro Systems custom built 950HP. The cam I now have (solid roller) is 255/259 @ .050, 110 lsa, 104 icl. The reason for only 4* between int/exh is that the 291 heads have been milled quite a bit, and my block is decked to .005, so I have exhaust valve clearance issues. The cam designer did the cam with this in mind. That will no longer be a problem with the other heads, so Im going with a solid roller, 253/263, .668, on a 108. Im pulling the TH400 for a rebuild, and when it goes back in, it will be with a new converter from Dynamic Converters. Custom built, 3200 brake stall, 4500 flash stall. Lets see, I think that about covers it for now. Heads are going to the shop this week, as soon as the springs that I have ordered to go with the cam, arrive.

I would not drop the heads size down that far.
I would either try a set of Brodix RR BB-R 294 cc or a set of the Brodix BB-1 heads with a 280 cc port volume.

Thanks Eric....Im assuming you're talking about the port volume?? I thought about that too, but two reasons...first and foremost is Cash! I want to use what I have. Second, I dont want to spend big bucks on aftermarket heads, then mill them down so they will give me decent comp. with my pistons. No one makes a small chamber, big block head. If I start out with something at 100cc or so, Im way ahead. That, and with my nearly 100% street use, I wont be turning big rpms anyhow...and along the same lines, Im going with 2.19 intakes, no need for the 2.25's. Just saved more money, now I can return them.

Originally Posted by 1JohnnyO

Thanks Eric....Im assuming you're talking about the port volume?? I thought about that too, but two reasons...first and foremost is Cash! I want to use what I have. Second, I dont want to spend big bucks on aftermarket heads, then mill them down so they will give me decent comp. with my pistons. No one makes a small chamber, big block head. If I start out with something at 100cc or so, Im way ahead. That, and with my nearly 100% street use, I wont be turning big rpms anyhow...and along the same lines, Im going with 2.19 intakes, no need for the 2.25's. Just saved more money, now I can return them.

Here is another option.
Edelbrocks #60489 (bare head),oval port,100 cc combustion chamber size,290 cc port volume.

1JOHNNY O
U MEAN TO TELL ME YOU ARE NOT GOING TO STREET RACE THIS THING? YOUR GONNA GET SMOKED BY SOME SMALL BLOCK OR HONDA,LISTEN TO ERIK! DONT RETURN THOSE 2.250's LET THAT PUPPY BREATH,

my up grades are one set of 18 olds dart heads c n c 450cfm or so with 2.400 intakes valves and 1.900 ex and a 275/285 @.050 with 780/780 at lash on a lsa 115or117 and 13to1 should get the job done if not thats ok it is just a street car

WORD'
PAT. (OR IN OTHER WORDS)
I CONCUR DR. McCARTHEY

Originally Posted by TT572ZZILLA

1JOHNNY O
U MEAN TO TELL ME YOU ARE NOT GOING TO STREET RACE THIS THING? YOUR GONNA GET SMOKED BY SOME SMALL BLOCK OR HONDA,LISTEN TO ERIK! DONT RETURN THOSE 2.250's LET THAT PUPPY BREATH,

No, there is no street racing here! And Im certainly not worried about hondas. As I dont rev this thing very high, the 2.25's would have no value to me, and the extra weight, although not much, is an added detriment.

Originally Posted by 1JohnnyO

No, there is no street racing here! And Im certainly not worried about hondas. As I dont rev this thing very high, the 2.25's would have no value to me, and the extra weight, although not much, is an added detriment.

The cam you have should make power to 6,000 rpm's with good heads.
If you put those small heads on the engine you might as well pull out the mech. roller cam and put a hyd. cam in it.
I would guess those oval port heads and your mech. roller cam would be done before well before 5,000 rpm's making any power.

Eric, what are you basing the 5K limit on?? I know of several guys running slightly worked oval port heads (closed chamber at that) that are pulling an easy 6500 rpms, and running deep in the 10's with their combo. I know with the heads Im proposing, Im not gonna pull to 7K, but then again, I dont have to. And for the record, Im going to look at those eddys that you mentioned, but I doubt they're going to be in the budget. Thanks for the link though! John

Originally Posted by 1JohnnyO

Eric, what are you basing the 5K limit on?? I know of several guys running slightly worked oval port heads (closed chamber at that) that are pulling an easy 6500 rpms, and running deep in the 10's with their combo. I know with the heads Im proposing, Im not gonna pull to 7K, but then again, I dont have to. And for the record, Im going to look at those eddys that you mentioned, but I doubt they're going to be in the budget. Thanks for the link though! John

They might turn the engine to 6,500 but they are done making any hp with those small oval port heads.

you say you would not need the 2.250 intakes that would be the first thing i would do to your heads and 11/32 stems with the small ports . you do not have a396 your engine is a 500cid ? them valves will not hurt one bit. i would go to260/270@050 651/677 lc107 or 256/266 641/636 lc 107

Those ports are way too small for a 505ci. I would just keep the heads you have and throw some NOS on it. Call it a day.

IVE GOT DART 308's ON MY 500 INCHER W/2.350's W/ALL THE GOOD STUFF AND A 288/292 @.50 .750 I/E 112 IN ON A 108! ITS QUITE CRISPY ALL THE WAY ACROSS THE RPM BAND
WHAT DO YA THINK PAT?
GOTCHA BACK MAN [IM COVERING YOUR BACK]

what do i think you would have to put a gun to my head to put small iron ports on that engine any thing over 500 cid would like abit more port cc.but if your looking to be done at 5000rpm they may work but i would put the big valves in them. there just no way i think you can get all the air/fuel with a small valve and get any hp or TQ