[Motor Daddy]

Cliff, I'll bet my next check, that if you switch the crank out to a smaller stroke, it will shift your powerband up considerably!

[Jim Hand]

JC You,
Agree completely that adding CR to any engine will almost always help performance. Whether it will do it with 92 octane pump gas is the real unknown.

Concerning your comment about possible detrimental effecs of 30 degree intake seats on the KRE heads, don't understand that one! Here are actual flow numbers, all off the same bench with the same inlet adapter. The 64, KRE, and 6X numbers are the averages of all 8 ports- the 87 cc E head is for one cylinder. The 64 and 6X were fully ported by yours truly:

The KRE intake seats are 30 degrees with a 50 and a 65 blend cut. The exhaust is a double radius with a 45. Both intake and exhaust valves were back cut - (all same as the 64 and 6X). I smoothed the KRE port at the push rod bulge but was very conservative so as not to risk break through. The port height was increased to Fel Pro gasket HO size. Other then blending the seats/cuts, slightly flattening the PR bulges, and opening the intake runners to the HO gaskets, no porting was done. However, I did minimally resurface all areas with a sanding roll in order to see how it all looked after the NC work.

Intake ----------------- Exhaust
Lift 64, KRE, E head new 6X ---64 KRE, E head new 6X
.05 45 42 35 42 -----32 30 27 29
.1 86 80 69 78 -----62 66 56 71
.2 163 160 139 150 -----117 120 108 129
.3 205 214 205 195 -----149 159 144 168
.4 237 247 245 236 -----177 192 169 194
.5 250 265 268 264 -----196 211 184 211
.55 254 269 270 267 -----202 218 187 218
.6 256 273 272 268 -----204 224 192 223
Port Vol 165 187 216 170

JC, again, please explain how those flow numbers could/would have degraded performance as compared to 45 seats.

And I also agree that if a practical reduction in port volume of the KRE heads could have dropped them to about 170, substantal ET and 60' increases would have been noted.

Motor Daddy,
I am a little concerned by beging chastised by a guy whose claim to performace is with a 400 engine, 6.0 gears,(or whatever), 200 shot of NOS, and you can spin your tires. But haven't been to a dragstrip! I suggest you find a track and substantiate some of the stuff you have been posting and then come back on and provide the results! That is what both Cliff and I have have done for years!

And Motor Daddy, as far as your comment "people talk about changing a part that shifts the powerband up, and then talk about how they slowed down when they kept the same gear, and launched and shifted at the old RPM! Go figure!"

Those "high RPM" KRE heads ran 11.69 at almost 115 with 3.31 gears and at 4050#, while shifting at 5500. How does that compare to to the performance of your "super strong high RPM" 400 setup?

Again, I never stated the KRE heads did not work well, did not state they won't work on most cars, did not state they won't work on about any level of performance car. But I did try to explain and show the board how techniques, RPM, gears, weight, and drivability change with different types of parts, and most specifically port volume, or more technically correct "cross sectional area of the intake port".

And most importantly, Motor Daddy, I have actually ran at a drag strip, and have a full and complete record of events for years. So I do not appreciate your wise-A. comments about "using wrong parts"! Using different parts is how I have found what really works, and why my car remain's competitive with most other similar weight cars!

Jim Hand

[Skip Fix]

Bruce I've had good luck with UD cams in several motor. Their 288/296 has similar 0.050 specs as an 041, I've run before. Jim's is a little bigger(234), Aubry Parker in Dallas has a 455 that runs low 11s and has a Comp 236 or 242 @ 0.050 cam forgot which exact lobe, so I felt a step bigger was the ticket to insure mid 11s in the heat.

559.66hp! (according to Walace Racing calculator, using 3750 lbs.),-engine dyno was only 525 hp so you can see how dyno to dyno comparsions aren't apples to apples.I had tach issues that night at the track so used the factory tach that only goes to 6000 for shifting, Dyno peak was 6200, so even bigger heads can be shifted lower and still make adequate power if you don;t want to hammer on everything.

[Motor Daddy]

Jim, I made a general comment about powerbands, and you fly off the handle at me? Maybe you are choking on some of your own medicine? Just because I choose not to make my street vehicle into a track vehicle, doesn't mean I don't know what's going on. I'll leave it at that!

[grandville455]

Dont mean to hijack here,How does one figure out the port volume of a head... just curious as to what mine are ...here's my flow sheet on my 6x-8 heads...would like to know if i am getting that kind of flow with not alot of port volume? Can it be checked with heads on the car?
thanks!

[slowbird]

It can not be check with them on the car. In order to check intake cc's they need to be off of the car. Position head so that intake surface is level. get buret or something that measures cc. Fill it up with a fluid (water or alcohol will work) then pour that into the intake port once it is full that amount that it took to fill it is the cc of you intake port.

[slowbird]

Jim I know that you dont want to go with a 45* seat. But on my 62 heads the flow at .300 lift was 220cfm with the 45* seat. Also I believe what JC is talking about (please correct me JC if Im wrong) is that when a head is designed to work with a certain seat angle that it might not work that well when you just change the seat and nothing else. The bowls are usually bigger when using a 45* seat over a 30* seat. Also the combustion chamber has ALOT to do with how the head will work with a seat angle. The thing about using 30* seats is that the flow cone in much wider than if you use a steeper angle. Yes using a shallower angle makes for a bigger window early on in the lift cylce but you are direction that flow out torwards the cylinder wall instead of down into the cycle. Darrin Morgan (the main guy at Reher and Morrison as far as head porting goes) has said that even if he ported a head for a class that had a rule for limited lift of .500 that he feels that a properly done head with a 55* seat would make more power than the other seat angles. The reason is the flow cone and chamber shape. There is so much more to making power than just looking at flow numbers on a bench. Chamber shape, port shape, wet flow are all more important (in my opinion) that what the head flows.

[Bruce K]

Originally Posted by Bruce K

559.66hp! (according to Walace Racing calculator, using 3750 lbs.), Wow nice, I'm hoping to rpm 6000+, trying to save my tranny until I can get a Tremec.

I checked out your cam (239/247) on the Lunati (Holley) site. I can't understand why they rate your cam as being more agressive than solid rollers like the 507A3LUN (255/263). Can you shed any light on the subject? Thanks, Bruce

Skip, I still don't understand, the smaller solid roller cam has more dur at .050 than the larger adv. dur hydraulic cam, yet Lunati has lower proposed requirements. Do you think it's a typo or real?

hyd adv - 296/304, .050-dur 239/247, .507/.530", 4200-4500 stall, 11:1, 4.56
solid rllr 288/296, .050-dur 255/263, .626/.626", 3000-3500 stall, 10:1, 3.90

[Bruce K]

I called Lunati, the descriptions listed are just estimates and to be taken with a grain of salt. Sheeeesh

[Jim Hand]

Slowbird,
"more power" as in "peak power", or total average power from idle to 5500?

Jim Hand

[Bruce Meyer]

Jim-Is there a particular reason why you didnt spin it past 5500 with the KRE test? Are you worried about blowing it up? Cast rods maybe? Not trying to bag on you. Just curious.

[Jim Hand]

Bruce,
The trans governor is set to shift at that RPM, and there was never any plans to change the operational RPM of the car, regardless of heads. Accordingly, we never even considered changing the shift point. We have good rods, and could have run whatever RPM we wanted.

I simply wanted dependable replacements for the worked over iron heads that hopefully would run a little quicker. As they not only didn't run a little quicker, but were worse in ET while 50# lighter, I lost interest in trying to make them work better then iron after five trips to the track and installation of a custom cam.

There is no doubt that I could have changed the RPM range of the entire engine/chassis setup and ultimately make them run quicker. But that was never a consideration before, during, or after!

And again, the KRE heads are excellent pieces for about any application. But so are my iron heads for my car!

Jim Hand

[Bruce Meyer]

Jim- Ok I see. That makes sense. The trans gov makes the car more consistent I would gather. Ive been thinking of modifying the gov on my car to shift automatically. Did you use a B&M kit or modify yours by grinding? I dont think B&M makes the kit for TH 400,s anymore.

[Jim Hand]

Bruce,
I used a B&M kit. While it is possible to do it without the kit, the kit contains an assortrment of axles, clips, spring, weights, and gaskets. The latest kit number is B&M 20248, and both Jeg's and Summit lists it - it includes parts for the 700 in addition to the 350 and 400.

Note: The Governor furnishes oil pressure, based on engine power and throttle position to both the 1-2 and 2-3 shift valves. So both are affected with a change to the governor full throttle pressure. I have found it is best to calibrate the 1-2 shift first and then determine where 2-3 shifts. If they are close, leave them, or split the diffference.

If they are not close, then modify the 2-3 shift valve spring pressure. It can be done by shortening/weakening the 2-3 shift spring by clipping a coil at a time, or by making the spring stronger by shimming with small washers. A stronger spring will hold second higher in RPM.

And if you do plan to calibrate the 2-3 shift valve/spring, a minor mod will make it much easier. The 2-3 spring is held in place with a loose roll type pin in the valve body. The pin is removed from the top of the body when the body is removed. And is held at the bottom by the valve body. Simply drill through the existing partial hole in the lower portion of the body such that the pin can fall out the bottom of the valve body. Then rig a small retainer of soft metal or strap fastened under the closest vavle body bolt to hold the roll pin in place.

With this mod, the 2-3 shift can be altered without removing the valve body! And while you have the pan off, install a drain plug on the right side about 2/3 of the war to the rear. Then enough oil can be drained to lower it below the gasket level and the pan can be removed with having a transmission oil bath each time!

Surprisingly, many things can slightly affect the shift points even after calibration of the governor and shift springs. Head wind, uphill vs downhill, engine power, and other things can shift the RPM by as much as 50 or even more! The reason is the centrifugal weights respond to "rate" of acceleration in adddition to actual RPM. So anything that makes the car accelerate slower will allow it to shift a bit earlier! Not a big deal, but it means you must be aware of this when initially calibrating the governor.

Jim Hand

[Jim Hand]

Received the May, 2006 issue of Popular Hot Rodding, which describes the build-up and testing of the third place engine in this year’s Engine Master Challenge. The engine is a 509 cube Ford and it scored 1258 points, with the scoring being the total quantity of HP and ft-lbs of torque between 2500 and 6500 RPM. It was built and entered by John Lahone from Livernois Motorsports

I noted one very important similarity in John’s prep and testing, and my engine and the testing I have conducted. Of course, I haven’t made 200 dyno pulls as he did, and my engine is in no way comparable in any aspect. But we were/are both interested in port size and its relation to airflow and power spread. Here is what John said about the heads he used:

“We tested the first set of cylinder heads, which flowed really well, but the runners were fairly small, and then we tested a second set that were quite a bit bigger and we had better numbers with that. The airflow was better at the top, and we ended up gaining 13 points with the bigger heads. Instead of going for the higher velocity small ports, we went for a little less velocity and bigger ports and it responded.”

In other words, port size and velocity, and attendant airflow, was important enough that John tested different heads to find the optimum balance of size and flow for his engine. And he used the pair that made the most total power within the RPM range he was competing in.

That is exactly what I did with the head test I made – didn’t have the luxury of 200 dyno pulls, but did obtain a fair amount of time slips at the track. And I found, just as John did, that moving power from one end of the desired RPM range by changing port size could make measurable differences in usable power. In my case, more flow and bigger ports lost more power on the bottom then was gained on the top. In John’s case, the opposite was true. It was only a 13-point change out of 1258 points, but was certainly important enough to change heads (sort of like my “only .1-.2 second” at the track).

Again the message I have tried to impart in this thread and others like it is this:

Port size/volume is important if you are trying to maximum performance. And it must be balanced with the required airflow for the RPM range the engine will be loaded in.

In my case, the load range is about 1700 to 5500 – in John’s case, it was 2500 to 6500. The actual port sizes he used (approximately 3.25 sq. in.) are immaterial and certainly not applicable to our engines, but the principle he used in experimenting and testing for the best balance of port size and required airflow most definitely is applicable!

The article has a wealth of other technical details used and is worth the read.

Jim Hand

[bobzdar]

"The trans governor is set to shift at that RPM, and there was never any plans to change the operational RPM of the car, regardless of heads. Accordingly, we never even considered changing the shift point. We have good rods, and could have run whatever RPM we wanted."

This does not make sense to me? If merely shifting manually would allow you to possibly run faster, why not at least try it? There seems to be no limitation preventing you from shifting the car higher. If it turns out to run faster and is shifted at 5700rpm, you could then say you don't want to run that high (I don't know why), but putting an artificial limit on the shift point for no reason at all seems kind of crazy to me...

[Skip Fix]

As we've both said experimentation for the combination is what's needed for any motor even these high end motors.

The recent article in HPP on the 4th place Kaase Pontiac(our motors) operated in the same rpm range(2500-6500) as this and even with the extra large 310cc port Tiger heads probably had as much torque on the bottom end and HP as most of us with alot smaller heads have. 619 ftlbs @ 2500! Alot more bottom end than mine has with 90cc smaller ports! Look at the large % change from a 235cc ported E head to a 310 cc Tiger that still has that bottom end. So you can design bottom end and top end with large ports if the whole package matches on a Pontiac motor,bigger doesn't have to be bad if matched with ALL the other components.A few more CI , but then a 4.25 stroke has more CI over a 3.75,4.0 and 4.21 stroke motors we've been talking about using KRE or E heads.

Adding a shift point up to 5700 or 6200 from 5500 I don't think is that big a jump,some may. 6200 isn't even a 10% jump, one that most folks just looking to go faster that have the good rods don't mind making,at least I don't. Just like changing from a 3.08 gear to a 3.36, not a big change in rpm. Different goals for different folks.

[Skip Fix]

One other interesting item on the Kaase motor was the "small" duration at 0.050 roller, gobs of lift to take advantage of the heads liking lift. And one used from data on other engines built the past couple of years, I assume other makes since the Tiger heads haven't been out for a couple of years. So maybe our Pontiacs do respond like other engines.

[J.C.you]

port ccs can be a little misleading on the tiger heads as they have a spacer attached to the head and surely increase port volumne. also the port volumne can be varied greatly by the larger bowl area area in the tiger head/ versus the old dport design......

although port ccs and crossectional area are both important numbers in a head design, min or max CA will usually have more of a direct effect of what rpm a head will make power..........

[slowbird]

The Tiger head doesnt have a built in space. It is seperate so unless they cc'd the intake with the spacer bolted on the 310cc is just the runner. Althought the runner being raised as much as it is makes it longer than any other Pontiac intake runner and that will add volume.