[S/st 54]

Originally Posted by pastry_chef

congrats on the numbers Bill!
you're gonna make the RA V guys cry...

Me personally I don't think Bill does it to make anyone cry. He works on every cylinder head the Pontiac world has to offer. I think he does what he does cause he loves doing it. I think we all benefit from guys like that.



Keep brewing that Kool-Aid BRO!

[R 70 Judge]

What shortblock works with this head? I'm guessing, but I'm coming up with a 4.40" bore x 4.75" stroke turning 8,600+rpm. Sound about right?

[BruceWilkie]

541 should work.(maybe a 511) 2.4 valve is ok on 4.375 bore(54.8% valve to bore 54.54% if 4.4 bore). Suspect 541 may not need to go 8600 if the cam intake and headers do their job. But 8600 rpm is doable. 511 would want to rpm higher but geometry of valvetrain should help ease the task. Especially if it doesnt need to run 1" plus lifts to get there (which just might be the intent of this port). Will be interesting to see where this port finalizes. I dont expect peak lift flow to increase, just improvements to stability above .850 lift numbers. Bill dont like dips in his flow curve.

[twinturrbo406]

Originally Posted by R 70 Judge

What shortblock works with this head? I'm guessing, but I'm coming up with a 4.40" bore x 4.75" stroke turning 8,600+rpm. Sound about right?

... that is approaching 7000/fpm of mean piston speed, so i'd say no ...

... i'd go with a 4.400 X 4.070 in a 9.300 deck block, 6.125 aluminum rods, 15to1 compression, BIG camshaft, a Sheet/Tunnel Ram and dual 4's, and turn it about 9000-9100 rpm, which puts you at about 6100/fpm, i think that would work well and make some really serious HP ...

... just playin' around with a couple simulation programs, and they predict a range of about 1200-1275hp & 730-775 ft/lbs, for what ever thats worth, but it does give an idea of expected power levels ...

[twinturrbo406]

Originally Posted by S/st 54

Greatgto, I was jokin on the 068 cam thing. I think Bills doing a great job (So is the other head porters IMO) these numbers show a boat load of potential, I just hope these things can go on a motor soon........but for now digitizing would be another big step I'd like to hear about.Keep up the good work Bill.

... well, i'm not so sure about it being good work today Jason, as i seemed to have pissed it off, lol ...

... i lost about 6-10cfm in various places across the range, it was still above 500 cfm @ .850 lift, but i think its safe to say, now i know what it does NOT want the floor and short-turn to look like ...

... i have added some epoxy to the floor, and we will be working at it tomorrow to see how that goes ...

[GREATGTO]

Originally Posted by twinturrbo406

... that is approaching 7000/fpm of mean piston speed, so i'd say no ...

... i'd go with a 4.400 X 4.070 in a 9.300 deck block, 6.125 aluminum rods, 15to1 compression, BIG camshaft, a Sheet/Tunnel Ram and dual 4's, and turn it about 9000-9100 rpm, which puts you at about 6100/fpm, i think that would work well and make some really serious HP ...

... just playin' around with a couple simulation programs, and they predict a range of about 1200-1275hp & 730-775 ft/lbs, for what ever thats worth, but it does give an idea of expected power levels ...

Thats what Id want, to me these are the builds we need to be doing, throw this engine in a 3rd or 4th gen and go have some fun, if you wreck it go buy another one for 1000 bucks. Plenty of 6 cylinder cars out there with perfect interiors and body.

[lemans411]

Originally Posted by twinturrbo406

... well, i'm not so sure about it being good work today Jason, as i seemed to have pissed it off, lol ...

... i lost about 6-10cfm in various places across the range, it was still above 500 cfm @ .850 lift, but i think its safe to say, now i know what it does NOT want the floor and short-turn to look like ...

... i have added some epoxy to the floor, and we will be working at it tomorrow to see how that goes ...

Stop pissing it off bill! Theres enough of that in the pontiac community. : )

[R 70 Judge]

Originally Posted by twinturrbo406

... that is approaching 7000/fpm of mean piston speed, so i'd say no ...

... i'd go with a 4.400 X 4.070 in a 9.300 deck block, 6.125 aluminum rods, 15to1 compression, BIG camshaft, a Sheet/Tunnel Ram and dual 4's, and turn it about 9000-9100 rpm, which puts you at about 6100/fpm, i think that would work well and make some really serious HP ...

... just playin' around with a couple simulation programs, and they predict a range of about 1200-1275hp & 730-775 ft/lbs, for what ever thats worth, but it does give an idea of expected power levels ...

CSA seems large for that application, but I'm sure you know something I don't. I'm not a head porter nor am I an engine builder. Keep up the good work! Looks like it will be one bad mofo when it's done

[bankbook]

Good work Bill!!

[twinturrbo406]

Originally Posted by R 70 Judge

CSA seems large for that application, but I'm sure you know something I don't. I'm not a head porter nor am I an engine builder. Keep up the good work! Looks like it will be one bad mofo when it's done

... you are correct, the CSA i started with is too big, but i set the roof and left the floor a bit low, and have been adding epoxy a little at a time on the floor/ssr to refine the shape, and the CSA is less now ...

... but thanks ... i hope so too ... but i did spend some time on it today, and this is where i'm at currently, it still is backing up a bit, but i'm trying to get the mid numbers as strong as i can without the dip up top, but it looks like its costing me some up top, so far anyways ...

... but the port is coming around, so i'll keep playin' with it until i get it ...

(CV-360)"under construction"

.100 - 91.8
.200 - 176.6
.300 - 254.3
.400 - 313.6
.500 - 382.8
.600 - 439.2
.700 - 476.0
.800 - 492.5
.900 - 486.1
1.00 - 492.4
1.10 - 502.9

[john marcella]

Originally Posted by twinturrbo406

... you are correct, the CSA i started with is too big, but i set the roof and left the floor a bit low, and have been adding epoxy a little at a time on the floor/ssr to refine the shape, and the CSA is less now ...

... but thanks ... i hope so too ... but i did spend some time on it today, and this is where i'm at currently, it still is backing up a bit, but i'm trying to get the mid numbers as strong as i can without the dip up top, but it looks like its costing me some up top, so far anyways ...

... but the port is coming around, so i'll keep playin' with it until i get it ...

(CV-360)"under construction"

.100 - 91.8
.200 - 176.6
.300 - 254.3
.400 - 313.6
.500 - 382.8
.600 - 439.2
.700 - 476.0
.800 - 492.5
.900 - 486.1
1.00 - 492.4
1.10 - 502.9

If its just a model head, use Bondo. Only 3-5 min. I hate waitingLOL

Look at the back of the valve (the 12* part). At what lift does it cross the plane of the deck surface ( the back of the valve). Probably right were your having the problem. The air is probably upset with making the transition from the chamber to the bore. I have this going on right now, but i dont give a chit

[twinturrbo406]

Originally Posted by john marcella

If its just a model head, use Bondo. Only 3-5 min. I hate waitingLOL

Look at the back of the valve (the 12* part). At what lift does it cross the plane of the deck surface ( the back of the valve). Probably right were your having the problem. The air is probably upset with making the transition from the chamber to the bore. I have this going on right now, but i dont give a chit

... i use splashzone for an area i need to really shape by hand and make it lay down real nice, but for something quick, Pig-Putty works great, have you ever used that stuff John ?? it's pretty cheap too ...

... the chamber does still have a bit of a lip or corner in that area to the valve, i'll lay it back and see if it helps, thanks ... but i'm not to the bore scribe on the chamber yet either, i doubt thats it though ... but yes its a head-half ...

[twinturrbo406]

Originally Posted by john marcella

If its just a model head, use Bondo. Only 3-5 min. I hate waitingLOL

Look at the back of the valve (the 12* part). At what lift does it cross the plane of the deck surface ( the back of the valve). Probably right were your having the problem. The air is probably upset with making the transition from the chamber to the bore. I have this going on right now, but i dont give a chit

... i worked the chamber a bit more, and it seemed to help the dip, so i think you are on to something there John, this particular chamber was bore-scribed on a 4.350 bore block, so it has some more room to unshroud the valve, but it really helped the low lift i think ...

... i didn't take it all the way out, i went about 70% or so to the scribe, so i'll work the chamber some more tomorrow and see what happens, but the sides of the short-turn are extremely sensative in this port, man what'a pain, i agree with you though, i hate waiting too ...

... but even with the dip in flow, the port recovers quickly, so i think i'm real close to nailing this thing, i hope i didn't just jinx myself ?? ... lol ... but this baby is really crankin' now, man the low lift is very nice, heck, if i can get the dip out of it with 490cfm at the peak, and this mid-range flow, man i'll be happy as a pig in " ---- " !!! ...


(CV-360)

.100 - 95.9
.200 - 184.2
.300 - 253.1
.400 - 323.5
.500 - 392.7
.600 - 443.5
.700 - 478.7
.775 - 493.7
.800 - 485.3
.900 - 490.8
1.00 - 500.7
1.10 - 510.1

[R 70 Judge]

I've never seen midlift numbers that high before. 323cfm at .400"? If that is all accurate cam it for .800" lift and call it done.

[BruceWilkie]

Originally Posted by R 70 Judge

I've never seen midlift numbers that high before. 323cfm at .400"? If that is all accurate cam it for .800" lift and call it done.

Many would... there is a reason he wont... I understand the reason but he can explain it much better than I can.

[twinturrbo406]

Originally Posted by R 70 Judge

I've never seen midlift numbers that high before. 323cfm at .400"? If that is all accurate cam it for .800" lift and call it done.

Originally Posted by BruceWilkie

Many would... there is a reason he wont... I understand the reason but he can explain it much better than I can.

... well keep in mind this port has a 2.400 valve in it, so there is a lot of curtain area to work with, the issue with that is the bigger the valve, the bigger the port, and if you can only go so high in a head, then the turn through the apex gets tighter ...

... making shaping the port to navigate that turn more difficult, and sensative to changes in shape, but basically in a perfect world you want no dip in flow at all, but sometimes you get into situations like this where you are pulling a lot of CFM through a head that's not a super tall entry like this one ...

... now if there is a small dip in flow, then the port comes right back the next .100 lift increment, then in a running engine this is not a big deal, but if a port dips or backs up 20-30cfm and does not come back at all, then there is a big problem and it needs to be corrected, the dip in flow i'm dealing with is not that bad, i'm just picky and i want it gone, or at least as much of it as i can get, i think i'm real close though ...

[blueghoast]

Your more than welcome to test them on my motor.
And we can use my tempest for a road test too.

GT.

[john marcella]

Originally Posted by BruceWilkie

Many would... there is a reason he wont... I understand the reason but he can explain it much better than I can.

Area under the curve.

[john marcella]

Originally Posted by twinturrbo406

... i worked the chamber a bit more, and it seemed to help the dip, so i think you are on to something there John, this particular chamber was bore-scribed on a 4.350 bore block, so it has some more room to unshroud the valve, but it really helped the low lift i think ...

... i didn't take it all the way out, i went about 70% or so to the scribe, so i'll work the chamber some more tomorrow and see what happens, but the sides of the short-turn are extremely sensative in this port, man what'a pain, i agree with you though, i hate waiting too ...

... but even with the dip in flow, the port recovers quickly, so i think i'm real close to nailing this thing, i hope i didn't just jinx myself ?? ... lol ... but this baby is really crankin' now, man the low lift is very nice, heck, if i can get the dip out of it with 490cfm at the peak, and this mid-range flow, man i'll be happy as a pig in " ---- " !!! ...


(CV-360)

.100 - 95.9
.200 - 184.2
.300 - 253.1
.400 - 323.5
.500 - 392.7
.600 - 443.5
.700 - 478.7
.775 - 493.7
.800 - 485.3
.900 - 490.8
1.00 - 500.7
1.10 - 510.1

Try on the spark plug side of the chamber, were the chamber meats the deck, radius the transition with about a .060 -.100 radius.(SMALL) Only the spark plug side of the chamber. Its kinda like a heavy deburr and just roll it off. It should help that point.

Nice numbers.

[GREATGTO]

Looks great Bill, those numbers are incredible down low. As sensitive as this port seems I hope it can maintain your final results when it makes the transition from a work piece to a cnc program, slightest changes seem to move the numbers around fairly easy.


Seems like you are almost where you want to be though.Again very nice work.