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 73 ponitac 455 with 4x heads
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Tub
Sitting Bull

172 Posts

Posted - 17 Aug 2016 :  9:39:13 PM  Show Profile  Reply with Quote
Have never heard anything good about those KB "hypercast" pistons.

And, they cost nearly $100 more than the SP forged pistons.

https://www.summitracing.com/parts/uem-kb133-060/overview/make/pontiac

http://www.ebay.com/itm/Speed-Pro-TRW-Pontiac-400-Forged-Coated-Skirt-Flat-Top-4VR-Pistons-Set-8-060-/172099504041?hash=item2811ee07a9:g:1SsAAOSwe7BWvhuB&vxp=mtr

For about $100 more, you can buy some light Auto-Tec pistons, with thin rings & your choice of pin locations. There are also some good Icon pistons, for about $500.

http://www.cnc-motorsports.com/icon-ic890-060-forged-flat-top-pistons-4-180-bore.html

https://www.rpmmachine.com/shop/index.php?l=product_detail&p=6220

But, hopefully you won't have any problems with your pistons.


Edited by - Tub on 18 Aug 2016 12:19:20 AM
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Phil
The Great White Buffalo

USA
7216 Posts

Posted - 17 Aug 2016 :  10:06:47 PM  Show Profile  Reply with Quote
Yes I was doing the same thing Cort. It gets confusing when threads piggyback on each other.

Ok so now the 6X heads are making more sense. Go with 6X4's (common 350 heads) though so you don't have to mill them as much. You can sell the 48's if you need to recoup some money. If not, I'd stash them away for a rainy day.

Where in NJ? I'm in Pa. but only 15 mins from Trenton.

Bowties are for Pee-wee Herman. "Chevy": even the name sounds cheap, but not as cheap as your Pontiac will be with an LS transplant.
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Tesla49
Tribal Scout

15 Posts

Posted - 18 Aug 2016 :  08:37:54 AM  Show Profile  Reply with Quote
you're not far from me, maybe about 2 hour ride. not sure if you have heard of parsippany or newark? to give you an idea. It's north jersey.

Edited by - Tesla49 on 18 Aug 2016 08:50:18 AM
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Phil
The Great White Buffalo

USA
7216 Posts

Posted - 18 Aug 2016 :  8:12:15 PM  Show Profile  Reply with Quote
Lol yes I have worked in Newark in a previous life. Also have been to the airport countless times. Newark airport is an hour from me via NJ Turnpike.

Bowties are for Pee-wee Herman. "Chevy": even the name sounds cheap, but not as cheap as your Pontiac will be with an LS transplant.
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Tesla49
Tribal Scout

15 Posts

Posted - 22 Aug 2016 :  10:13:04 AM  Show Profile  Reply with Quote
Larry from Hansen Racing knows his stuff, all I can say is if you want someone in your corner this guy is the guy to have. Should have heads this week. So to recap for those looking to build a nice street car, take some advice from someone who gambled and lost, keep it between 8.5 to 9.5 compression unless you plan on aluminum heads or mixing race fuel. If you can afford it, have the builder install the engine, and remember that the warranty is only as good as the person or company providing it, having them install it will limit the amount of excuses, but not entirely. Too high of a compression will give indicators of poor fuel, this all has to do with the flame front and how it progresses through the burn, you may hear many talk about quench, peak pressure, decay, dynamic compression etc. don't take that stuff lightly, you can ignore it, but if you overshoot your desired octane level on your build, it will be very difficult to rectify, don't think that a twist of the distributor or dumping more fuel is the cure, by the time you go through all the tricks and gimmicks of larger cams to "bleed off compression" cooling tricks, etc. you will find they are a band aid mostly for a particular rpm range. They may have their purposes on the race track, but you don't need to go to that length in a nice street car if you just know the limitations of the engine and the fuel you are using, and most certainly do lots of research on engine builders, if you don't see many reviews on them building your particular type of engine, maybe its best to look elsewhere, Wish I did. Finally... Good Luck.

Edited by - Tesla49 on 22 Aug 2016 4:43:01 PM
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Tesla49
Tribal Scout

15 Posts

Posted - 26 Aug 2016 :  2:29:29 PM  Show Profile  Reply with Quote
Just got some #46/6h heads milled .020, with 2.11/1.77 valves, I know they aren't anything special but beggar's cant be choosers. this should put my compression @ 9.3:1.
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Phil
The Great White Buffalo

USA
7216 Posts

Posted - 26 Aug 2016 :  9:19:00 PM  Show Profile  Reply with Quote
What's done to the heads and were the larger valves put in before or did you have done? 73-74 350-400 (2 barrel engine package) heads? @98 cc's or so?

Bowties are for Pee-wee Herman. "Chevy": even the name sounds cheap, but not as cheap as your Pontiac will be with an LS transplant.
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Tesla49
Tribal Scout

15 Posts

Posted - 27 Aug 2016 :  03:22:14 AM  Show Profile  Reply with Quote
they were small valve heads may 16, of 1973. had the larger valves installed.

Edited by - Tesla49 on 27 Aug 2016 03:23:39 AM
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Pontiac Dude
Sitting Bull

USA
199 Posts

Posted - 01 Sep 2016 :  09:15:02 AM  Show Profile  Visit Pontiac Dude's Homepage  Reply with Quote
quote:
Originally posted by Tub

Have never heard anything good about those KB "hypercast" pistons.

And, they cost nearly $100 more than the SP forged pistons.

https://www.summitracing.com/parts/uem-kb133-060/overview/make/pontiac

http://www.ebay.com/itm/Speed-Pro-TRW-Pontiac-400-Forged-Coated-Skirt-Flat-Top-4VR-Pistons-Set-8-060-/172099504041?hash=item2811ee07a9:g:1SsAAOSwe7BWvhuB&vxp=mtr

For about $100 more, you can buy some light Auto-Tec pistons, with thin rings & your choice of pin locations. There are also some good Icon pistons, for about $500.
http://www.cnc-motorsports.com/icon-ic890-060-forged-flat-top-pistons-4-180-bore.html
https://www.rpmmachine.com/shop/index.php?l=product_detail&p=6220
But, hopefully you won't have any problems with your pistons.



I stay away form the............. hyper pistons and just step up to the forged pistons. Hypers are JUST cast pistons with a different production formula. If u run hot or don't have the wider ring gap u can have an issue.

## 1976 T/A, Hydraulic roller, 3460lbs, stock suspension & Pump gas. N/A: 9.78@136 ##

I Specialize in ALL American Muscle Iron.
https://www.facebook.com/kensautomachineshop/?pnref=story
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Pontiac Dude
Sitting Bull

USA
199 Posts

Posted - 01 Sep 2016 :  09:43:27 AM  Show Profile  Visit Pontiac Dude's Homepage  Reply with Quote
I know this is probably late but have a 455 (400 block with a cut down 455 crank) with 4X heads in my 79 T/A. Love it.
8.5-1 compression. runs on 87 octane. has a #068 cam. ported 4X heads with 2.19/1.77 valves, Holley street dominator with a Thermoquad carb.
stock converter, 3:73 posi. 3700 lbs. Completely stock suspension except for traction bars. Runs in the 12.90 range shifting at 4800 rpm.
Have run a ATI procharger (centrifugal supercharger) with this combo. 7 lbs boost 12 flat.
Have run a 150 nitrous shot 12 flat.
Going to go back to the ATI Procharger (when time and money permit) set up as ............... it's different and actually picked up 2 mpg. :)

## 1976 T/A, Hydraulic roller, 3460lbs, stock suspension & Pump gas. N/A: 9.78@136 ##

I Specialize in ALL American Muscle Iron.
https://www.facebook.com/kensautomachineshop/?pnref=story
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cortcomp
Coyote

USA
5335 Posts

Posted - 03 Sep 2016 :  08:52:18 AM  Show Profile  Visit cortcomp's Homepage  Reply with Quote
My 69 is very original (looking at least, the engine is a 70 455 engine). Jim Taylor built the 455 for the PO as a mild street motor, fun but nothing crazy. I need to dig out the cam specs and see if it can take some boost. I feel like even just 5-10 lbs boost would make it a lot more fun street car, but then i start imagining the hassles trying not to over-modify everything, carb tuning, and i get lazy just thinking about it.
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Tesla49
Tribal Scout

15 Posts

Posted - 06 Sep 2016 :  07:57:22 AM  Show Profile  Reply with Quote
Heads are on, car fired right up, no complaints from starter, no ticking, tapping, pinging, or knocking noises, Technician rubbed it in, saying " I told you the compression was too high right from the start" (I sided with Denny's at first), so I had to eat a little crow. I can't get on it for now because the engine has to break in since its second rebuild, also have to wait for the shop to get a new wide band 02 sensor for the air/fuel meter in order to setup the carb for the upteenth time. Now that the compression is around 9.3:1, I will probably have to change all the parts I bought for the carb and distributor since I was listening to the wrong person, I might even put my chinese pcv valve back in since the ME Wagner is a little obtrusive looking, that alone was $100+ in the toilet, although their customer support was fantastic, it is overkill for my engine. I Filled up the tank with sunoco 93 to dilute the race fuel I had in the tank, and she runs good. Will update when completely finished.
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cortcomp
Coyote

USA
5335 Posts

Posted - 06 Sep 2016 :  09:43:21 AM  Show Profile  Visit cortcomp's Homepage  Reply with Quote
Good news! Wishing you many more miles of trouble free fun!
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Tesla49
Tribal Scout

15 Posts

Posted - 21 Sep 2016 :  1:03:06 PM  Show Profile  Reply with Quote
thanks for the well wishes. After 8 months of horror, she is on the road. simply put... wrong heads for the specified job. So go ahead and use sunoco gas and put those Chinese pcv valves back on, because it wasn't the $40 dollar items that killed the engine, it was the $5000 build that was supposed to run on pump gas. With the #48 heads off and CC'd we put the numbers in the Wallace Racing calculator and it was 11.3:1, Gee could that be a problem?! exactly what my Tech told me 1 hour after getting the engine installed, he knew it and he didn't even build the damn thing, I guess not all ASE certified techs are the same. It's nice dropping your kids off at school and getting thumbs up from other kids and teachers, somehow it helps ease the pain. Thanks to Larry at Hanson Racing, great guy and builder, no arrogance, just knowledge, I really can't thank him enough for the time he took in his busy schedule to bail me out, and thank you to this board because this was a great resource for me over the past few months to debunk the line of garbage I was hearing from the builder.
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Lee
Sitting Bull

101 Posts

Posted - 11 Oct 2016 :  08:31:38 AM  Show Profile  Visit Lee's Homepage  Reply with Quote
quote:
Originally posted by Tub

Have never heard anything good about those KB "hypercast" pistons.

And, they cost nearly $100 more than the SP forged pistons.




I've built several well-running motors with the KB hypereutectic pistons, and never had a problem. Follow the directions for the ring gap, and do the math to make sure you have the right compression ratio. I was one of the first people to buy a set, as I already had good results using their Olds pistons.

KB was the FIRST manufacturer that offered D-shaped dishes and mini-domes to give Pontiacs the proper compression ratios with available heads.

I've had a SP "forged" (sorry example of a forging) break the head off. Have you ever actually LOOKED at one? There are only two straps of metal that hold the top of the piston to the skirt, probably 270-degrees through the oil ring is wide-open.

CURRENT: '73 T/A clone, boring at the moment...
67 Firebird (sold) 11.27 @ 119.6 Feb. '05 issue HPP
69 Falcon wagon, 10.51 @ 130mph Feb. '10 issue PHR (sold)
72 Cutlass Convertible, first car, owned since '82, now with a 6.0 LS, mild, putting just under 400 hp/tq to the wheels.
www.LNLPD.com
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cortcomp
Coyote

USA
5335 Posts

Posted - 11 Oct 2016 :  09:58:59 AM  Show Profile  Visit cortcomp's Homepage  Reply with Quote
That may be on the SP, but how many millions of them out there running with no issues? I've read good and bad on the KB as well, but i've never had a failure of either (because i'm afraid to rev because i hate rebuilding things twice, so i'm just kind of a wus on that.)

However, i have read nothing but negative on using any kind of dome on a pontiac. While i know chevys, fords, and others use domes to change compression, i've read 100x over it just kills flame travel in a pontiac, and results in less power. Again, never tried them myself, fwiw.

I think for most anything, you'll find someone who has had nothing but good luck, and the guy who using that part or brand ruined his entire life. For most, i'd let motor use, and budget decide what parts you go with.
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Tub
Sitting Bull

172 Posts

Posted - 11 Oct 2016 :  11:19:08 AM  Show Profile  Reply with Quote
"... i have read nothing but negative on using any kind of dome on a pontiac...i've read 100x over it just kills flame travel in a pontiac, and results in less power..."


While it is probably true that a flat top piston will make more power than a dome, IF the compression is about equal for both engines. But, I would assume that a dome would increase compression enuff to make a performance increase, if you had to use low compression heads. For example: how about if you had to use unported 6x-8 heads on a 400. These engines were advertised to have only 7.6 compression. So, would using a small dome increase compression enuff to make more power than with flat tops ? I assume the increased CR would allow the use of a slightly larger cam also.

vhttp://www.ebay.com/itm/Speed-Pro-TRW-Pontiac-400-Forged-Coated-225-Dome-Pistons-MOLY-Rings-Kit-30-/191782714134?hash=item2ca723fb16:g:ebQAAOSwYIhWl7GA&vxp=mtr

This Speed-Pro page says the L2279NF30 pistons will give 9.31 CR with 96cc heads. I'm assuming these would make more power in a 400 with 6x heads, than with flat tops. But I can not link any dyno proof of it.

http://powerforgedpistons.com/engines.html

Other advantages of these pistons, over stock replacement types, are floating pins and narrow rings.

H-O Racing Specialties built a 700hp engine using dome pistons.

http://www.originalho.com/326Engine/326Engine.html


Edited by - Tub on 11 Oct 2016 2:57:53 PM
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Blued and Painted
Chief PONTIAC

USA
3406 Posts

Posted - 11 Oct 2016 :  12:01:07 PM  Show Profile  Reply with Quote
quote:
Originally posted by Tesla49

I guess not all ASE certified techs are the same.

Just like any other professional group.
I remember coming out of tech school, many of the guys would take and pass the ASE tests in there last quarter before graduation. School counted for work experience. So you could be ASE certified mechanic without earning a dime actually working on cars.
The tests themselves are only basic questions about automotive principals and generic components.
Shops will pay more for certifications. So For young aspiring mechanics, go ahead and get certified. Then continue to get re-certified, then re-certified, then re-certified for the rest of your automotive carrier.
So IMHO, ASE certification is a racket. When the dealership sends you to the manufacturer run classes, the detailed learning will begin.



Bull Nose Formula/ 461/ Q-Jet/
TH400/ 3.08 8.5 / R44TS.

Edited by - Blued and Painted on 11 Oct 2016 12:05:04 PM
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Blued and Painted
Chief PONTIAC

USA
3406 Posts

Posted - 11 Oct 2016 :  12:27:00 PM  Show Profile  Reply with Quote
On a side note.
Tub, formally Ponyakr, left this sight in a snit because he got called out on some bad advice.
So read his posts with a grain of salt.


Bull Nose Formula/ 461/ Q-Jet/
TH400/ 3.08 8.5 / R44TS.

Edited by - Blued and Painted on 11 Oct 2016 12:39:03 PM
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Tub
Sitting Bull

172 Posts

Posted - 11 Oct 2016 :  2:45:22 PM  Show Profile  Reply with Quote
quote:
Originally posted by Blued and Painted

On a side note.
Tub, formally Ponyakr, left this sight in a snit because he got called out on some bad advice.
So read his posts with a grain of salt.



Yeah, I remember all that very clearly. It was caused mostly by a Pontiac engine builder, who was always touting the CC XE series cams above all others, and always badmouthing the old style 041/Rhoads lifters combo. And, as I remember it, there seemed to be a LOT of forum members who backed him up 100%. I can remember that he & Cliff Ruggles had some pretty intense conversations about the XE cams.

BUT, this engine builder seems to have had some problems lately, no longer posts, and has gotten some extremely bad reviews by some of his customers. Anyhow, I decided to start posting again. I don't claim to be an expert Pontiac engine builder. And, if I had plenty of $$$, I would probably never, or very rarely ever post on a forum. I'd be busy racing & playing with my street & race Pontiacs.

But, at present I have lots of spare time to kill. Reading & talkin about Pontiacs is about all I can do. So, I'd like to continue to post on the Pontiac forums, including this one. BUT, if most of you guys prefer that I leave, I will. I have no quarrel with anyone who has a different opinion than mine. BUT, when I read about one person's opinion & have read of others opinions, which differ, I think it adds to the conversation to present this opinion.

Hey, that may not be a good idea at all. Might be best for everybody on a site to have the same opinion. So, I'll let you guys & Mr. Bill decide. If ya'll want me gone for good, you'll never hear from me on this site again. I won't leave in a "snit". I'll just leave in order to make this site more peaceful, and with fewer opposing opinions.

I mean no offense to anyone. I don't even know any of you guys. PEACE Pontiac brothers.
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cortcomp
Coyote

USA
5335 Posts

Posted - 11 Oct 2016 :  3:03:01 PM  Show Profile  Visit cortcomp's Homepage  Reply with Quote
Only part of the above i think is kind of broadly painted is:

"BUT, this engine builder seems to have had some problems lately, no longer posts, and has gotten some extremely bad reviews by some of his customers"

Well, by issues, he was almost blind and had tons of health problems. Happens to everyone. I read of one extremely bad review, and it looked like the person he sold the business to botched something. Maybe he did, who knows. *Shrug* I was a happy customer. He had many other. Same as the speedpros vs KB pistons above.

not really related to the above comment but worth mentioning:

He was/is a big fan of the XE combos; he sold a ton and the customers were happy. One XE284 he had dyno'd at 500hp IIRC. I wouldn't say they are terrible as Cliff and others do.

My only complaints about the XE vs the rhoads + 041 are as follows:

1) XE grinds are notoriously clacky. OK, run the rhoads + 041 combo. Oh wait, that's clacky til they pump up. Sounds like they're both kind of band-aids with compromises in that department.
2) rhoads+041 require decent compression, correct? Guys are wanting $600+ for bare high compression heads. The XE grinds, i feel, are aimed at the low comp engines of 70+, of which heads are way cheaper. I feel they're a different application but people seem to love comparing them together. Set your budget or look at what parts you have, and that will seem to set the cam options for you.
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Lee
Sitting Bull

101 Posts

Posted - 12 Oct 2016 :  11:17:16 AM  Show Profile  Visit Lee's Homepage  Reply with Quote
quote:
Originally posted by cortcomp

However, i have read nothing but negative on using any kind of dome on a pontiac.




This is a mini-dome. It is JUST enough above the plane of the piston to offset the valve reliefs, resulting in "0" cc's. Not nearly enough dome to hinder flame propagation. It was designed for people using cylinder heads from 100-110cc's, to get the CR into the 9's.


CURRENT: '73 T/A clone, boring at the moment...
67 Firebird (sold) 11.27 @ 119.6 Feb. '05 issue HPP
69 Falcon wagon, 10.51 @ 130mph Feb. '10 issue PHR (sold)
72 Cutlass Convertible, first car, owned since '82, now with a 6.0 LS, mild, putting just under 400 hp/tq to the wheels.
www.LNLPD.com
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Lee
Sitting Bull

101 Posts

Posted - 12 Oct 2016 :  11:18:23 AM  Show Profile  Visit Lee's Homepage  Reply with Quote
LOL!! Sorry for the huge picture!! I took it off of their site, and it was MUCH smaller on there!

CURRENT: '73 T/A clone, boring at the moment...
67 Firebird (sold) 11.27 @ 119.6 Feb. '05 issue HPP
69 Falcon wagon, 10.51 @ 130mph Feb. '10 issue PHR (sold)
72 Cutlass Convertible, first car, owned since '82, now with a 6.0 LS, mild, putting just under 400 hp/tq to the wheels.
www.LNLPD.com
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Blued and Painted
Chief PONTIAC

USA
3406 Posts

Posted - 12 Oct 2016 :  11:39:32 AM  Show Profile  Reply with Quote
So Mr. Lee, have you seen these pistons used successfully in hot street applications?


Bull Nose Formula/ 461/ Q-Jet/
TH400/ 3.08 8.5 / R44TS.

Edited by - Blued and Painted on 12 Oct 2016 11:40:09 AM
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Lee
Sitting Bull

101 Posts

Posted - 14 Oct 2016 :  7:24:04 PM  Show Profile  Visit Lee's Homepage  Reply with Quote
quote:
Originally posted by Blued and Painted

So Mr. Lee, have you seen these pistons used successfully in hot street applications?



I have used them in 455 Olds, 400 Pontiacs, 428 Pontiacs, and 455 Pontiacs that I have built myself. Mostly built to have compression ratios in the 9.2 to 9.5 range. I ground the top & second ring gaps to be =/> than the minimum gap as stated in the instructions.

I've had XtremeEngery HFT cams fail several times, but never had a failure of ANY KB hypereutectic piston.

With that said, with some of the offerings of Race-Tec and Icon pistons, there are affordable forged pistons on the market that I would choose over a KB hyper.

CURRENT: '73 T/A clone, boring at the moment...
67 Firebird (sold) 11.27 @ 119.6 Feb. '05 issue HPP
69 Falcon wagon, 10.51 @ 130mph Feb. '10 issue PHR (sold)
72 Cutlass Convertible, first car, owned since '82, now with a 6.0 LS, mild, putting just under 400 hp/tq to the wheels.
www.LNLPD.com
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edbird
Tribal Scout

9 Posts

Posted - 16 Apr 2017 :  8:24:21 PM  Show Profile  Reply with Quote
quote:
Originally posted by cortcomp

Torquey is right about that setup. I was accidently laying rubber with it in the garage moving it around for the first time last night (6x-8 milled, XE284, 455 .030 over, pretty stickers all over it to add HP)



Sorry to refresh an old thread, but how much did you mill the heads? Thanks
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cortcomp
Coyote

USA
5335 Posts

Posted - 17 Apr 2017 :  10:07:33 AM  Show Profile  Visit cortcomp's Homepage  Reply with Quote
It's been a long while, but it wasn't anything crazy, maybe .012 or so? Honestly, seat of the pants, probably not a lot of difference if i didn't mill them. Just gets them straight, ups the compression a little to get you back some from the 50 years of valve jobs.
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