[bad69bird]

Curt you have a PM

[BruceWilkie]

http://www.hotrod.com/projectbuild/h...ild/index.html


http://www.hotrod.com/projectbuild/h.../camshaft.html You'll find 3 pics below the head flow chart that describes how Nelson "O"-rings and seals the heads. Basically the "O"-ring in the block forces the gasket into the receiver groove in the head. He coats the gasket with Permatex super 300 form-a-gasket.

Page 4 has the dyno story page 5 the dyno readings.

1025 hp on 91 octane 1502 on race gas Not shabby for a 406 SBC.

FWIW I plan on doing similar when I build my turbo'd 59 389 based 400. except I'll substitute Yamabond 4 two stroke case sealer for the permatex. It dries similar to the plastic "toy soldiers" are made from and is fuel-oil-water resistant.(two strokes use the case for intake of fuel/oil/air and have to seal between cylinders. The case is split at the crank. Yamabond4 works the best of any sealer I've used. ). The rest of my build will be similar to this SBC. I'm not expecting to acheive Nelsons numbers but I wont be too far off.

[aronhk_md]

This is all great info guys, and exactly what I was after with that question. Thanks for all the good ideas and info.

Now, on the other question.....anybody else want to chime in on the idea of low boost/higher rpm vs. higher boost/lower rpms on a mostly street driven combo?

[PONTIAC DUDE]

Originally Posted by taff2

You can run o ring wires in the block without reciever grooves being cut in the heads,with a copper or composition head gasket,just make sure the o ring wires don't stand up so high-0.004" instead of 0.010". If using composition gaskets you would have to check where the o ring wire sits in relation to the fire ring of the gasket. This way will work with iron or ali heads,easily at just 10-15 psi of boost,though ultimately double o ringing is better for serious boost.

Apparently you didn't read my above posts?
Wrong info as to wire depth and no receiver groove.
http://www.scegaskets.com/page/oring...tructions.html

[Jack Gifford]

Regarding the "1,000 HP @ 5,500 RPM", do you realize this constitutes 955 ft.lb. of torque at 5,500 RPM (by definition of horsepower)? This might give rise to some people questioning the data. In any case- given the cylinder pressures involved with numbers like these, I feel that copper gaskets and O-rings are called for.

[Just out of curiosity- is there a challenge involved in building a drivetrain to be reliable behind 955 ft.lb. of engine torque?]

[aronhk_md]

Jack, not really sure why this would cause "some people" to question the data. At this point, you are the only one to have done so, in an offhand sense. Anyway, I'm not really worried what anyone else thinks, as I have the dyno results right here...lol.

As for a reliable drivetrain...I wouldn't think there is any challenge to building anything to withstand that kind of torque...the transmission and rear end are from a Chevette.

[BruceWilkie]

Originally Posted by pontiac jack

Regarding the "1,000 HP @ 5,500 RPM", do you realize this constitutes 955 ft.lb. of torque at 5,500 RPM (by definition of horsepower)? This might give rise to some people questioning the data. In any case- given the cylinder pressures involved with numbers like these, I feel that copper gaskets and O-rings are called for.

[Just out of curiosity- is there a challenge involved in building a drivetrain to be reliable behind 955 ft.lb. of engine torque?]

Jack I absolutely agree. Trusting to standard head gaskets and hoping it never detonates is likely to cost more in the long run than doing it the safer way the first time. Even at lower power levels. When something goes wrong and you detonate you may not be able to react to what you hear because the damage could occur before you hear it. (I have first hand experience with that. Its not like getting a "ping" or "rattle" from a tid too much advance NA at modest load or a daily driver that prefers 89 octane over 87. )

I agree also that making 1000 hp with a turbo(s) while certainly do-able, is not as simple as some may think. Making 1000 hp reliable and staying together separates the talk from the walk. Good data helps back up claims. If the data is vague it brings more questions.

A T400 can be built to handle the power/tq but it certainly wont be stock. A strong rear as well especially if you find a way to hook all that power. Weight of vehicle also a player.

Perhaps you've been misunderstood. Someone comes across as ungrateful for your concern.

[Elarson]

A few miscellaneous bits of info:

1) we had to quit using composition gaskets when we got to about 1000 hp. We use copper gaskets now. No experience with Cometics, etc.

2) the receiver groove is important with a copper gasket. With no receiver groove, the o-ring indents into one side of the gasket and provides an interruption to the (potential) leak path on that side of the gasket only. The other side is still a smooth surface that can't tolerate any unloading w/o becoming an unrestricted leak. The receiver groove causes the gasket to deform and creates a leak barrier on both sides of the gasket. In a high horsepower engine, you have to plan ahead for how things will act when the heads inevitably lose some/all of their clamp load.

3) no gasket in the world will contain a detonating tuneup.

FWIW:
Eric

[aronhk_md]

Not ungrateful for concern, but I have purposefully left info about the car out of this discussion (for reasons I may explain later) and only mentioned the car itself because these questions are not specific to that car alone. My questions were 1) about boost, o-ringing and what were people's thoughts on those matters and how an engine should be set up. 2) whether it is better to attempt higher rpms/lower boost vs lower rpms/higher boost in a mostly street fairly stock bottom end 455 vehicle.

Notice I laughed after I mentioned him questioning the data. It doesnt bother me and I can share a laugh because as mentioned I have the dyno results, and I'm not really here to defend the results or how it is built at present. I'm here to ask questions so that as I make changes I can do so with a bit of knowledge. The setup has tons of room for improvement I believe, but that takes nothing away from the great job the gentleman who built it has done getting it to where it is.

The car in question has a hughes built trans and converter, but the rear end I would consider a weak point. Sorry if I tried to add a little levity here with the chevette reference. I owned one once, and the trans went onme at 50K miles...lol. I plan to make changes to the drivetrain......as in other places, but I'll probably do a new thread over in another section of the forum at that time.

[aronhk_md]

Originally Posted by pontiac jack

Regarding the "1,000 HP @ 5,500 RPM", do you realize this constitutes 955 ft.lb. of torque at 5,500 RPM (by definition of horsepower)? This might give rise to some people questioning the data. In any case- given the cylinder pressures involved with numbers like these, I feel that copper gaskets and O-rings are called for.

[Just out of curiosity- is there a challenge involved in building a drivetrain to be reliable behind 955 ft.lb. of engine torque?]

As for my response to Jack...here is how I took his statements.

"Regarding the "1,000 HP @ 5,500 RPM", do you realize this constitutes 955 ft.lb. of torque at 5,500 RPM (by definition of horsepower)? This might give rise to some people questioning the data."

While it has been many years since I took physics, and I would have to sit down with an equation to see if Jack is correct, I'm not sure why anyone here would "question the data". As far as I can see it was meant to be one of those little edgy things things to throw in his 2 cents on a matter that doesnt really have any bearing on the questions. His next statement starting "anyway...." is when he actually addresses these questions.

Why does this give rise to questioning the data?

Lets just assume at this point that I've made up the car in my mind. The questions I asked I still believe are good ones.

The final part of his statement continues the theme of the first part.......again completely off the topic and back to his questioning the car. '[Just out of curiosity- is there a challenge involved in building a drivetrain to be reliable behind 955 ft.lb. of engine torque?]" I believe Jack is quite aware that there is a challenge in doing something of this nature. He doesnt come out and ask what is in the car, but I believe he is to paraphrase, "questioning the data....."

I'm not trying to paint you as a bad guy here Jack, but I have seen too many people inject their own agendas into threads on this forum and others. I'm not angry. In fact I am perfectly ok. My attempt was to redirect with a touch of humor. Sorry if it didnt carry across well.

P.S. - There have been many posts already here I have learned from. Thank you to all. You too Jack.

[BruceWilkie]

Boost PSI is a measurement of restriction to flow. With PSI increase comes heat which leads to greater chances of detonation with a given fuel. Increased Rpm leads to additional mechanical stress.

Mass flow through the engine determines horsepower. NA increasing rpm is needed as a means to increasing mass flow. Superchargers can increase mass flow without raising engine rpm. Add higher flowing heads and you can get a cooler denser charge at a lower boost PSI level same engine rpm but increased mass flow giving you increased power.

So, do you want to increase addional stress of higher rpm with same power load? Or do you think lowering the rpm stress at the same power load would be safer?

Keep in mind that as boost PSI increases, the charge temp increases and that increases the likelihood of damaging pre-ignition induced detonation because the charge could be too hot and ignite before being fully compressed.

Water/alky injection is a good detonation suppressor. I used winter grade washer fluid in my homemade water injection(boost propelled/regulated) in the mid 70's junk gas years(finding 100+ octane was hard and getting relatively expensive then) on my modified turbo corvair pushing over 20 psi. Without it it would start to rattle near 7 psi. Water/alky has a charge cooling effect as well. The Corvair also had factory boost retard.

Intercooling also lowers boost psi and charge temp while allowing increases in mass flow.

How much boost you can safely run is dependant on a lot of factors.

[aronhk_md]

Good info Bruce. My thoughts then (for my own purpose).....if I'm building a 455 for the street I might want to keep the rpms below 6000 and work my way up with the boost to a max of say 15 psi, with an intercooler while making sure to remove enough ignition timing to avoid detonation. Large chamber heads for low compression. Preferably aluminum for heat dissipation. O-ringed block/heads with copper head gaskets. Monitor air/fuel ratio. Cylinder head temps? Perhaps a very small nitrous shot for competitive moments to cool the charge. Making sure the turbo is appropriately chosen for cfm/lbs of air/fuel mixture.

To answer your question.....if I understand correctly I likely want to have same power at lower rpm, especially in a 455 with 3.25 mains if I understand it right.

[BruceWilkie]

Originally Posted by aronhk_md

Good info Bruce. My thoughts then (for my own purpose).....if I'm building a 455 for the street I might want to keep the rpms below 6000 and work my way up with the boost to a max of say 15 psi, with an intercooler while making sure to remove enough ignition timing to avoid detonation. Large chamber heads for low compression. Preferably aluminum for heat dissipation. O-ringed block/heads with copper head gaskets. Monitor air/fuel ratio. Cylinder head temps? Perhaps a very small nitrous shot for competitive moments to cool the charge. Making sure the turbo is appropriately chosen for cfm/lbs of air/fuel mixture.

To answer your question.....if I understand correctly I likely want to have same power at lower rpm, especially in a 455 with 3.25 mains if I understand it right.

Sounds like a good possibility.

fwiw checkout turbo69bird here or over on PZ. He moderates the boost forum over there. He was well into the 9's with a 455 2 bolt(studded with good rods and pistons) stock heads and a performer intake. (878 hp iirc) Recently mild ported heads and switched to efi and initial extra safe tune up slightly slower.(still in the 9's) Should pick up next year as he tunes it in. He street drives this car. He is also a source for turbos and makes headers for some combos.

[taff2]

PDude, I didn't realise that it was only your opinion that counted around here. I've personally run composition gaskets (at 21 psi boost and 4 headbolts per cylinder)with just the block wired and the wire standing up 0.004". This wire cuts into the fire ring of the composition gasket. Wires standing up more than 0.004" with a solid copper gasket and no reciever groove can cause the head to stand off the block slightly.
I've never used annealed stainless wire as SCE recommends ,it seems at odds to me to use a soft wire that might flatten somewhat. I used steel mig wire,it's very hard and really cuts into the gasket, I used a copper hammer to tap it into the grooves. These are my experiences,or input, as Aron asked for.

[69Goat1]

Is this a pic of your new engine/car?

http://i601.photobucket.com/albums/t...a/DSC00647.jpg

Is this some info on it?

"Pics of it and some history on this site. There's 3 pages to look at. Also some good Pontiacs on the site.
http://www.americantorque.com/page/0/62/

This is 4 dyno runs from February of this year (2009). 91 octane 24 total timing. The first run shows 788 hp (at the wheels) but it says 15 psi. That run was only 10 psi. The second and third runs were 12 psi and the last run was 15 psi. Last run recorded 886.13 hp (1064 flywheel) and 823 ft pounds (986.7 ft pounds at the flywheel) on the 15 pounds. I'm having troule getting it to spool up on the line, with transbrake, sl ow I'm losing time at the track getting boost up. It has run 10.6 @ 129 but I'm losing at least a second with the lag. My exhaust piping going from the headers to the turbo inlt is 2.5 to 3 inch collector. I think that is too big. I'm going to try 2 inch. Just haven't got there yet.

http://videos.streetfire.net/video/F...DAY_643621.htm

I'm also changing over from the air to water intercooler you see in the pics to a front mount air to air intercooler. I think the air to water was to small choking my top end at the strip. It was laying down at the top end. The dyno runs were short enough to get the runs but if you listen close it sounds like the engine is topping out and stops pulling. It was the same on the strip. This is the front mount going in.

http://i601.photobucket.com/albums/t...heForty014.jpg

I'm waiting to get the piping back from the welder to finish the install and get it on the road."

[Tom Vaught]

Originally Posted by pontiac jack

Regarding the "1,000 HP @ 5,500 RPM", do you realize this constitutes 955 ft.lb. of torque at 5,500 RPM (by definition of horsepower)? This might give rise to some people questioning the data. In any case- given the cylinder pressures involved with numbers like these, I feel that copper gaskets and O-rings are called for."

Well Jack, The Luhn Performance 455 Engine made EIGHT HUNDRED NINETY ONE POUNDS/FEET OF TORQUE AT 4800 RPM at 13 psi of boost. You would only need 64 lbs/ft more torque to match that torque number for 5500 rpm in your quote above.

Why would you question the data? The Luhn Performance Engine was also run on one of the most accurate dynos in the country. The engine above probably was a much better engine than the Luhn engine too (which was really pretty basic).

Tom Vaught

I remember Marty P making over 1450 lbs/ft of torque on his 406 pontiac engine at 4900 rpm. He was on alcohol and more boost though.

[70 bird]

Originally Posted by aronhk_md

Good info Bruce. My thoughts then (for my own purpose).....if I'm building a 455 for the street I might want to keep the rpms below 6000 and work my way up with the boost to a max of say 15 psi, with an intercooler while making sure to remove enough ignition timing to avoid detonation. Large chamber heads for low compression. Preferably aluminum for heat dissipation. O-ringed block/heads with copper head gaskets. Monitor air/fuel ratio. Cylinder head temps? Perhaps a very small nitrous shot for competitive moments to cool the charge. Making sure the turbo is appropriately chosen for cfm/lbs of air/fuel mixture.

To answer your question.....if I understand correctly I likely want to have same power at lower rpm, especially in a 455 with 3.25 mains if I understand it right.

15 psi. is more than a handful on the street.

[aronhk_md]

Taff2

Thanks, I'm trying to absorb it all, and I realize there may be numerous ways to skin this cat, so glad to have all input and discussion.

Tom V

Thanks. While I realize that dyno results can vary, I certainly didnt get the impression it LIED as there were other cars dynoed the same day, some of which had made previous runs on other dynos as well.

69Goat1

Nice detective work...lol. I just spoke with Mark and checked with him to make sure he didnt mind if I mentioned here on the forum that I am purchasing his car. The purchase has been in the works for a few weeks now, and hopefully his 1973 turbo Trans Am will be making its way east right after Pontiac Heaven. I just didnt want to talk about the purchase without checking with him first. Yes, some information about the car is available by following those link.

Really my 2 questions here have more to do with PLANNING changes to the car than just the current setup. I want to have more knowledge before I make those changes. I have a lot of respect for what Mark has done with the car. I'm sure even in his mind it is not "finished". But, he wants a new project, and I want his trans am, so its a good match...lol.

Next question I'd like to post...probably separately...is one to encourage discussion on detonation. How to avoid it, how to detect it, etc. So many variables, but its does have such an important role in boosted apps. Can cylinder head temps give valuable info? Just trying to figure out how to word the questions...lol

Steve Barcak

I was wondering if you were going to recognize the car since Mark has talked about selling it, even though I know you havent seen it personally.

Mark is actually suffering from internet withdrawal. His computer is down with a virus. I have the same virus now on my laptop as well. I either gave it to him, or he gave it to me apparently...lol. They say it can happen when you are "swapping files" and dont use protection.........lmao

[Jack Gifford]

Originally Posted by bad69bird

... Is this 1000hp documented?...

When I read this, I thought that the stated power was being questioned- sorry if I misunderstood.

Seeing that the power peak occurred way down at 5,500, I was curious how much torque that required- so I cranked out the number. How many Pontiacs have made 955 lb.ft. (at their power peak) on an engine dyno? I think it's a very tiny number- but how about if someone who's more aware of the status-quo answer that, please?

Frankly, your notion that O-ringing requirement could relate somewhat-directly to boost pressure gave me the impression that you weren't well grounded in the fundamentals of the discussion. You appeared to not realize that torque output most closely correlates to cylinder pressure in a running engine.

[bad69bird]

Originally Posted by pontiac jack

When I read this, I thought that the stated power was being questioned- sorry if I misunderstood.

No Jack you didn't misunderstand my question. That was my first knee jerk reaction to the number, but after I thought about it some more and saw some other points that people made I was less skeptical.

...you're not loosing it! LOL