[Stan Weiss]

Originally Posted by Scott Roberts

Define "some time"

Scott,
I don't know how long people have been using them. I first heard about them 4 or 5 years ago. A few years ago there was a nice video on Tommy Youmans' car when it had the Warp 6 Pontiac engine on a Hub Dyno.

Stan

[TCSGTO]

Originally Posted by unruhjonny

I seem to recall an article from several years ago where these engines were dyno'd and came out nearly nuts on their respective ratings.

I think it was Muscle Car Review. The III made close to it factory rating, the IV made close to 400 HP. The OP may have been involved in that article. Maybe he can confirm the details.

[unruhjonny]

Originally Posted by Scott Roberts

There is a lot more power to be had in the F.A.S.T class.. stock appearing engines that make big power...

I absolutely know that a F.A.S.T. motor can go a whole lot further than this combination.

[Scott Roberts]

Originally Posted by Stan Weiss

Scott,
I don't know how long people have been using them. I first heard about them 4 or 5 years ago. A few years ago there was a nice video on Tommy Youmans' car when it had the Warp 6 Pontiac engine on a Hub Dyno.

Stan

Yes, I saw that vid... nasty biotch for sure...
Seems the hub dynos are the new thing... I had mine dyno'd on an old school chassies type.. pretty much destroyed a set of slicks... when I'm done with my new build, it will be on a hub dyno.. I can't afford to ruin another set of slicks...

[Scott Roberts]

Originally Posted by unruhjonny

I absolutely know that a F.A.S.T. motor can go a whole lot further than this combination.

Indeed it can! That's is one class I could never afford.. those guys get dirty! 78t/a's with 500ci ... look factory but damn!

[unruhjonny]

Originally Posted by Scott Roberts

Indeed it can! That's is one class I could never afford.. those guys get dirty! 78t/a's with 500ci ... look factory but damn!

agreed.

Before I figured out my plan for my car, I was always faced with the "well I could do this" scenario, which kept the scope of my plans somewhat muddied...
I decided to stick with the PSMCD because this limits the scope of what I'm going to, or willing to do to my car - and in doing so, it also theoretically keeps my expenses within reason.

This was a key factor why I sold my 455 last year.

[Scott Roberts]

Originally Posted by unruhjonny

agreed.

Before I figured out my plan for my car, I was always faced with the "well I could do this" scenario, which kept the scope of my plans somewhat muddied...
I decided to stick with the PSMCD because this limits the scope of what I'm going to, or willing to do to my car - and in doing so, it also theoretically keeps my expenses within reason.

This was a key factor why I sold my 455 last year.

Wish you the best on you endeavors... F.A.S.T. is a tough class..

[Steve C.]

Axle-hub type dynamometers have been in operation for 45 years.


.

[Scott Roberts]

Originally Posted by Steve C.

Axle-hub type dynamometers have been in operation for 45 years.


.

Just haven't been avaliable to the masses I guess..
I've only seen them in the last 5 years or so like Stan said...
Only dyno I'll use after my last experience..

[Scott Roberts]

Originally Posted by unruhjonny

agreed.

Before I figured out my plan for my car, I was always faced with the "well I could do this" scenario, which kept the scope of my plans somewhat muddied...
I decided to stick with the PSMCD because this limits the scope of what I'm going to, or willing to do to my car - and in doing so, it also theoretically keeps my expenses within reason.

This was a key factor why I sold my 455 last year.

If you're going F.A..S.T. class raing, u should start a thread... that class has always amazed me.. im sure many others here would subscribe!

[Steve C.]

John at our shop has found one session at a good hub dyno shop can eliminate quite a few testing sessions at the drag strip. He tunes for my friend Ralph Howard and his Mustang here.
Last session out with the car:

1.12 60-ft (soft)
3.03 at the 330 mark
1/8 mile 4.64 @ 151 mph

https://www.youtube.com/watch?v=qRh7SkOfd9A


.

[Scott Roberts]

Originally Posted by Steve C.

John at our shop has found one session at a good hub dyno shop can eliminate quite a few testing sessions at the drag strip. He tunes for my friend Ralph Howard and his Mustang here.
Last session out with the car:

1.12 60-ft (soft)
3.03 at the 330 mark
1/8 mile 4.64 @ 151 mph

https://www.youtube.com/watch?v=qRh7SkOfd9A


.

Yeah, it's kind quick..lol

[Tom Vaught]

Ford has had a 4 wheel "Hub" Dyno in the Ford Research Building for at least 20 years.

Most of the 11 cells that were there were conventional engine dynos or rear tire dynos.

Not sure about6 40 years ago but if you say so. Never paid any attention to that deal as most testing wants
to simulate a real car on the road, that means the tire component has to be there.

Tom V.

[Formulajones]

Originally Posted by unruhjonny

I seem to recall an article from several years ago where these engines were dyno'd and came out nearly nuts on their respective ratings.

I digress, I wanted to comment about something else entirely;
I noticed this:



now, before I say much else, could you tell me if this isn't a PSMCD eligible motor?
Because unless there has been another rule change, the rods alone should disqualify this motor...
Also iirc this engine should have had an advertised compression of 7.6:1, and if I am correct this would be a bump of more than a full point - which should again make it disqualify.

I have not read of any builds here that have the piston out of the hole, most are (if my memory serves me) about 0.020" down so that was interesting for me to read.
I normally read that with the piston down and the thicker fel-pro gasket, that engines like this often yield a marginal drop in compression;
granted the overbore helps kick it back up;
And in this example the reduced cc valve reliefs would help too - I cannot off hand recall the size of the cc valve reliefs in pistons from this period - can someone post this to help me out?

This is pretty cool to see the honest to goodness power that can be made from a very stock appearing motor.

You guys sure do some interesting engine builds!

Maybe Dennis will chime back in but I'll take a stab at it since I've built a few to PS rules and love doing this stuff.

From what I see from his build, it would be PS legal except for the exhaust manifolds. Since those years didn't use those manifolds they cannot be used on the car if you were to go PS racing. It would need log manifolds to compete.

Other than that, nothing jumps out as illegal in this engine. You are allowed a 1.5 compression bump over the stock advertised. Where these engines really gain some performance is compression. While we all look at advertised numbers in reality most all of these engines never really made that much compression. The virgin engines I've torn down have always checked as much as a 1/2 point below advertised. Either pistons in the hole by a BUNCH and cylinder head chambers that sometimes check a little bigger than advertised etc... Usually they come up a pinch short on advertised compression.
Given the fact that we can correct that on a rebuild certainly helps, then add that we are allowed a 1.5 bump over advertised is a plus, so you can see why some of these engines really respond to a good solid rebuild.
The piston sticking out of the hole or playing with quench has nothing to do with the rules. You can do anything you want there as far as I'm aware. Just don't exceed the compression limit and you're good.. Now if you get into small ring packages and checking drag playing with ring tension, that may or may not fly but checking that is near impossible without a tear down, and not something really practiced anymore that I'm aware of.

You can also do things like play with the valve job. You can't port heads or even gasket match anything, but nothing in the rules tells you what sort of valve job to run or what type of valve has to be in there, and a good valve job with someone that knows what your doing can pick up 30 cfm on some heads without touching a port or bowl. It's still PS legal. It's just a stock head with a good valve job.

Cams are supposed to be within 1 or 2% of lift and duration if I remember correctly. I never tried to fudge that with a Pontiac build but I did play with that a bit on a DZ 302 build I did since it's a solid flat tappet, there are maybe some things I interpret between the lines.

As far as rods go, I think there are accepted rods for PS drags, not necessarily required running stock rods. After 50+ years of abuse, many guys (and I'm one of them) really don't like spending the coin it takes to recondition and resize a 50 year old rod of marginal strength anyway. Especially Pontiac rods. Last set I did I had to go through 16 of them to get 8 good ones that could be rebuilt.
There is no HP advantage really to using an aftermarket rod other than possibly removing a bit of weight from the rotating assembly. But it's so marginal it's hardly worth talking about.
On my 400 RA III build I used the stock rods (this was many moons ago) and still working fine. On the DZ build I used an Eagle Sportsman I-beam rod that mimics a stock rod, close in weight but much stronger. Does nothing for HP and nothing about it should disqualify that from the PS drags. I figure this thing spins 7000 easily so it just makes good sense. After all it's more about safety and longevity than it is about HP. No one likes it when you throw a rod out and oil down the track, and it's definitely not good for the car or your wallet either, lol.

[RocktimusPryme]

My only question would be about the pistons being slightly out of the hole. Would a factory motor not more than likely be down in the hole?

My point being that a factory motor would be even worse than advertised on compression.

[unruhjonny]

I didn't mean to convey that pistion height was a factor in legality, just that I had never read of a build doing that before.

[steve25]

Many of the better builds strive to get the piston out of the hole by .005” to .008”.
This helps the motor to use the fuel that just goes unused sitting in that piston to wall gap .

[RocktimusPryme]

Originally Posted by steve25

Many of the better builds strive to get the piston out of the hole by .005” to .008”.
This helps the motor to use the fuel that just goes unused sitting in that piston to wall gap .

First of all to be clear, I think this thread subject is awesome. I love the info, so I dont want to be seen as being critical here.

Im not debating that at all that having the piston slightly out of the hole is the correct thing to do. I just mean we are mostly looking at this and marveling at the power this is making relative to how most of us view late 1970s powerplants. But to be fair, even though this build is pretty faithful, wouldnt a factory motor likely have slugs stuck down in the hole? Meaning that their already low advertised compression is even lower?

I just wonder how much more power this is making than if we had a legit NOS W72 laying around to dyno. Which I realize is asking a lot.

I did like the nugget that if you simply turned up the timing on some of these smog motors they would wake up. I didnt live through the era so my speed secrets are mostly based on non factory builds.

[unruhjonny]

Originally Posted by steve25

Many of the better builds strive to get the piston out of the hole by .005” to .008”.
This helps the motor to use the fuel that just goes unused sitting in that piston to wall gap .

I don't doubt it one iota!

It's just that I never read about this, it seems like all builds keep the slug about 0.020" down, and use the "double thick" replacement head gaskets.

I have recently bought some NOS head gaskets so that I don't need to raise the slug as much - the flip side is if I build it a smidge to hairy for pump gas, then I can swap in the thicker fel-pro (ect) gaskets, to bring compression down slightly.

[steve25]

Test have shown that decking the block to achieve near the same efftect as a high ring land piston is worth in terms of torque and hp at 5000 rpm a additional 5 of each, and at 6500 rpm a added 3 hp for a total of 8.