[Sirrotica]

Probably the only reason I haven't pulled the trigger on Speedmaster heads on their black Friday sale is the stories on the net of dropped valve seats, without any interest from the company about making it right.

If that happens your almost assured a expensive pile of scrap metal, and any money you saved on the initial purchase is wiped out. I've been close to pulling the trigger, but those posts make me re-think it every time.

[Half-Inch Stud]

Stan, that calc looks useful. Very high HP and TQ predicts for a 400.

Suppose the VE needs factored by Lobe ramp speeds? My studies have always tried to assess the required Octane to be ping-free, and looks like the Roller cams always have FAST ramps compared to ancient successful HYD Flat tappet cams. Roller Springs are bad enough, and seems to me Fast ramp roller cams work on aluminum heads but their fast ramps are not Street optimal for Iron heads...that prefer to ping.

Valve seat integrity with Aluminum heads keeps my wallet wad intact. Toyota Head MGR tells me their valveseats use a ceramic frits that gets laser welded into the head, for Production. Not Berylium, not stainless, no such press-in anything.

[Murf]

Originally Posted by GoatZillaRacing

There is more room. Installed height is 1.800 and coil bind is .740. You can play with different locks and shims to dial in your perfect spring pressures. We do a lot of these heads with Howard's/Comp components to reach the customer's goal.



https://pontiacspeedshop.com/as-cast...eads-complete/

These valve spring numbers seem wrong. Your site shows 1.080 bind .740 max lift.
These numbers seem closer but I have a question for anyone reading this thread.

According to the second set of numbers, the OP’s cam would be .125-.150 from coil bind. Isn’t that way to much clearance? I thought you aimed for .060 or so from coil bind.

Help me out, I’m trying to learn this stuff.

Again to the OP, nice build!

Thanks
My


Sent from my iPhone using Tapatalk Pro

[Stan Weiss]

Originally Posted by Half-Inch Stud

Stan, that calc looks useful. Very high HP and TQ predicts for a 400.

Suppose the VE needs factored by Lobe ramp speeds? My studies have always tried to assess the required Octane to be ping-free, and looks like the Roller cams always have FAST ramps compared to ancient successful HYD Flat tappet cams. Roller Springs are bad enough, and seems to me Fast ramp roller cams work on aluminum heads but their fast ramps are not Street optimal for Iron heads...that prefer to ping.

Valve seat integrity with Aluminum heads keeps my wallet wad intact. Toyota Head MGR tells me their valveseats use a ceramic frits that gets laser welded into the head, for Production. Not Berylium, not stainless, no such press-in anything.

Mark,
I don't see BSFC being that good with 9.5:1 CR. But I still see that HP at around 100% VE.

Engine_Size_=_405.7955__-__RPM_=_6000__-__Blower_Pressure_=_.00
Barometric_Pressure_=_29.9200__-__Temperature_=_60.00

Air_/_Fuel_Ratio_=_13.00000

_6000_-_RPM

BSFC_________________________________0.4600___0.46 50___0.4700___0.4750___0.4800
___VE%_____Air______Air______Fuel_____BSFC_____BSF C_____BSFC_____BSFC_____BSFC
__________kgs/s____lbs/hr___lbs/hr_____HP_______HP_______HP_______HP_______HP
_0.9750__0.3964__3146.163__242.013___526.11___520. 46___514.92___509.50___504.19
_0.9800__0.3984__3162.297__243.254___528.81___523. 13___517.56___512.11___506.78
_0.9850__0.4005__3178.431__244.495___531.51___525. 80___520.20___514.73___509.36
_0.9900__0.4025__3194.565__245.736___534.21___528. 46___522.84___517.34___511.95
_0.9950__0.4045__3210.699__246.977___536.91___531. 13___525.48___519.95___514.54
_1.0000__0.4066__3226.833__248.218___539.60___533. 80___528.12___522.56___517.12
_1.0050__0.4086__3242.968__249.459___542.30___536. 47___530.76___525.18___519.71
_1.0100__0.4106__3259.102__250.700___545.00___539. 14___533.40___527.79___522.29
_1.0150__0.4127__3275.236__251.941___547.70___541. 81___536.05___530.40___524.88
_1.0200__0.4147__3291.370__253.182___550.40___544. 48___538.69___533.02___527.46
_1.0250__0.4167__3307.504__254.423___553.09___547. 15___541.33___535.63___530.05

CARFOR_Version:_4.4.2_--_Registered_to:___Stan_Weiss

Stan

[GoatZillaRacing]

Originally Posted by Murf

These valve spring numbers seem wrong. Your site shows 1.080 bind .740 max lift.
These numbers seem closer but I have a question for anyone reading this thread.

According to the second set of numbers, the OP’s cam would be .125-.150 from coil bind. Isn’t that way to much clearance? I thought you aimed for .060 or so from coil bind.

Help me out, I’m trying to learn this stuff.

Again to the OP, nice build!

Thanks
My


Sent from my iPhone using Tapatalk Pro

Installed height is 1.800. Max lift with a hyd flat tappet cam is .580 (more starts getting too much pressure) Max lift with a hyd roller is .740 and coil bind is basically 1.000 so 1.800 less .740 leaves you with .060 before coil bind. You don't need to set springs to their max prior to coil bind, you need to set them for the cams ramps and the intended RPM range. BTW, we always recommend 1.65 rockers which would put him at .615 lift. Thanks

[Baron Von Zeppelin]

Originally Posted by J Druin

Before going to the dyno the machine shop that does my work said it is a conservative dyno, no inflated numbers. So, I thought between 400 and 450HP would be ok but hoping for the higher side.

You would likely go past the 450hp mark on a happy/feelgood dyno.
Great street build with realistic goals and comfort margins.
Turned out nice !
I know a lot of us would appreciate follow-up posts when you get it out on the road.

Originally Posted by 1968GTO421

In looking at post #1 the OP shows his cam spec sheet where the lobe lift is 0.373 and the valve lift (with 1.5) is .560. Someone correct me if I'm wrong but this sounds to me like a hydraulic roller cam and not a HFT.

He posted it was HR (hydra roller) and cam sheet shows it has the 4-7 swap also.

[pastry_chef]

Originally Posted by Stan Weiss

I don't see BSFC being that good with 9.5:1 CR. But I still see that HP at around 100% VE.

Sheets for reference.
10:1 compression SBC 388.
AFR 195 heads.
Isky Hyd Roller 244 / 252 @ .050 .558 valve lift both I/E. 110 LSA.
Holley Strip Dominator intake with 750 carb.
Dyno is conservative.
Nearly 460 TQ at 3500 RPM,, outstanding.

[Murf]

Originally Posted by GoatZillaRacing

Installed height is 1.800. Max lift with a hyd flat tappet cam is .580 (more starts getting too much pressure) Max lift with a hyd roller is .740 and coil bind is basically 1.000 so 1.800 less .740 leaves you with .060 before coil bind. You don't need to set springs to their max prior to coil bind, you need to set them for the cams ramps and the intended RPM range. BTW, we always recommend 1.65 rockers which would put him at .615 lift. Thanks

Thanks for the explanation Randy!

Murf


Sent from my iPhone using Tapatalk Pro

[steve25]

Very nice 388 SBC!

[scott70]

I think these power numbers are pretty good,,,should move your car very nicely!! My 455 with iron heads dynoed best at 32 degrees.Tried 30 and 34. What do these speedmaster heads flow out of the box?

[GoatZillaRacing]

Originally Posted by scott70

I think these power numbers are pretty good,,,should move your car very nicely!! My 455 with iron heads dynoed best at 32 degrees.Tried 30 and 34. What do these speedmaster heads flow out of the box?

https://www.facebook.com/PontiacSpee...84014848693438

Prices have gone up but flow numbers are the same.

[Dragncar]

Originally Posted by pastry_chef

Sheets for reference.
10:1 compression SBC 388.
AFR 195 heads.
Isky Hyd Roller 244 / 252 @ .050 .558 valve lift both I/E. 110 LSA.
Holley Strip Dominator intake with 750 carb.
Dyno is conservative.
Nearly 460 TQ at 3500 RPM,, outstanding.

Mike Lewis is a very interesting guy. Lots of cool tales about his racing days, guy knows everyone.
I should have taken more pics of his builds in progress when I was at his shop.
Best equipment money can buy sitting in a little shop in the middle of the woods.

[Dragncar]

Originally Posted by steve25

I am not putting him down, nor am I a hater by any means, and I am sure as Hell not jealous, so stop your second guessing as to my nature or my intentions please!

He certainly was kind enough to post his dyno results with these heads used and by doing such was asking for a opinion, which I gave, and I fact I gave the SBC build as a reference for my opinion and the info from the Edelbrock ad, so I gave 2 examples, and not just opinion!

If you do not want opinions then don’t do posts asking for such!


The simple fact is that his 400 build would be making more power if he was running the KRE or Edelbrock D port heads on his 400!

Anyone care to comment as to why?

All this just goes to show how the combos we build need to be crafted more carefully and that’s because I know our Pontiac motors can equal the power of this SBC build I posted info about.

Here’s a great old example from the 1991 in terms of a 400 build with ported iron D port heads that certainly where not flowing what those out of the box Speedmaster heads are.

Anyone recall this 475 hp build that Pete McCarhy did ?

I will take a stab. Probably the same reasons Dan W had better results from his ported D ports on 400s than as cast E heads back in the day. Customers bought then new E heads and put them on their 400s and made less power.
Ports were not properly sized for the cid. Hard to get enough squeeze on the 400 with 72 cc chambers.
Vic called Dan and asked what the Pontiac world needed in a aluminum head. He asked for the RPM head but in 3 different chamber sizes. One 65cc or less for 400s. He did not get his wish.

[1968GTO421]

Randy,
I've been thinking about digging out my VISA for a set of these Speedmasters but I always hesitate because concerns as mentioned in this post:

http://forums.maxperformanceinc.com/...5&postcount=61

Hopefully you can give me some reassurance about this problem. To buy the heads and then have my machinist do new valve seats to prevent problems kinda negates the savings over other heads

[HWYSTR455]

Very nice build and numbers, you will be happy with that!

Not sure why so many bash the Holley Avengers, they are 'good' carbs, you just have to go thru them like with any part. Run the .130 needle & seat, they sometimes have issues on the higher rpm side. Last one I did I ran safety wire thru the passages to ensure there was no casting flash or crap, and they are dirty right out of the box.

I recently did an 870 for a friend on a 488 stroker build, and it was within 10hp of a professionally built $1200 Holley. And believe that was due to the .110 needle & seats that were in it.

.

[steve25]

Last Summer a worked on a set of these for a guys BBC , and one Intake seat was moving already after 300 miles on the street and some 34 passes at the strip.

If your looking to build even a 455 cid motor of about 500 hp I would go for the Edelbrock or KRE D port heads!
I do not trust the lack of consitant tempering on these heads!

[dragracerx2813]

Originally Posted by steve25

Last Summer a worked on a set of these for a guys BBC , and one Intake seat was moving already after 300 miles on the street and some 34 passes at the strip.

If your looking to build even a 455 cid motor of about 500 hp I would go for the Edelbrock or KRE D port heads!
I do not trust the lack of consitant tempering on these heads!

So is there a way to check the seats before using them?

[steve25]

It's not so much the seats and there press fit into the ,its how hard the Aluminum as a whole has been tempered which aids in supporting the seats above a certain amount of spring seat pressure.

[grandam1979]

I have found plenty of problems with Edelbrock heads just do a search you will find them to. I have done a lot of research on the speed masters and I seems a lot more positive than negative.

[HWYSTR455]

I heard the same issues with the E-head and other offering when they first came out, and time have proven it was isolated cases.

The Olds crowd has been doing the SpeedMaster heads for years, no issues.

If you want to take a 'safe' approach, wait some time while the production line works out kinks, and you will be fine.


.