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#101
08-06-2023, 01:27 AM
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More photos to come...
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#102
08-06-2023, 01:31 AM
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More Photos to come...
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#103
08-06-2023, 01:35 AM
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More photos to come...
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#104
08-06-2023, 08:33 AM
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Notches on pistons should be located to the front of the engine.
Looks like yours is mounted backwards. |
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#105
08-06-2023, 10:41 AM
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Quote:
Tom V.
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"Engineers do stuff for reasons" Tom Vaught Despite small distractions, there are those who will go Forward, Learning, Sharing Knowledge, Doing what they can to help others move forward. |
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#106
08-06-2023, 11:01 AM
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I wonder if the rod chamfers are turned correctly toward the crank fillets.
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#107
08-06-2023, 01:15 PM
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"At one time THAT was supposed to give you a few extra HP at the drags."
Correct. The county you live it will also hire you to kill mosquitos with the oil smoke coming out the exhaust when you quickly knock the rings out of it!.......LOL....
__________________
If you can read this, thank a teacher. If you can read this in English, thank a Veteran! https://cliffshighperformance.com/ 73 Ventura, SOLD 455, 3740lbs, 11.30's at 120mph, 1977 Pontiac Q-jet, HO intake, HEI, 10" converter, 3.42 gears, DOT's, 7.20's at 96mph and still WAY under the roll bar rule. Best ET to date 7.18 at 97MPH (1/8th mile), |
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#108
08-06-2023, 02:14 PM
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Quote:
We have to thank our aftermarket piston manufacturers for doing away with the pin offset; and at least Ross usually makes the eyebrows the same size which is another thing to not worry about. Basically as long as the valve reliefs are facing up and the rod chamfers are correct things are good.
__________________
Mick Batson 1967 original owner Tyro Blue/black top 4-speed HO GTO with all the original parts stored safely away -- 1965 2+2 survivor AC auto -- 1965 Catalina Safari Wagon in progress. |
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#109
08-06-2023, 03:06 PM
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The pistons could be hung correctly on the rods just installed backwards. In any case it needs to come apart and some changes made in that area. Mistakes happen, and it's a LOT easier with a Pontiac build the being different in lay-out than a Chevy engine.....
__________________
If you can read this, thank a teacher. If you can read this in English, thank a Veteran! https://cliffshighperformance.com/ 73 Ventura, SOLD 455, 3740lbs, 11.30's at 120mph, 1977 Pontiac Q-jet, HO intake, HEI, 10" converter, 3.42 gears, DOT's, 7.20's at 96mph and still WAY under the roll bar rule. Best ET to date 7.18 at 97MPH (1/8th mile), |
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#110
08-06-2023, 04:45 PM
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Often Hot Rod mods (by some) cause far more issues than the actual hp gain.
"PONTIAC Engineers DID stuff for a reason" Tom Vaught Tom V.
__________________
"Engineers do stuff for reasons" Tom Vaught Despite small distractions, there are those who will go Forward, Learning, Sharing Knowledge, Doing what they can to help others move forward. |
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#111
08-06-2023, 08:28 PM
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I can tell you first hand what happens when you install pistons with the "F" to the rear and offset in the wrong direction. I did it once. To this day I don't know how, other than the pistons were "odd" and no "F " on the top or "notch" to indicate direction. They were also only two valve reliefs with the reliefs the same size which made things even more confusting. The were marked on the sides of the pistons with an "F". Somehow I messed all of them up and paid the price for it.
I put the engine in service and ran it about 10,000 miles. It was a SBC 400 (406). It never sealed up well and consumed about a quart of oil every 600 miles or so. Ran just fine other than oil fouling a plug once in a while. I ran it long enough to make sure it was NOT going to get any better and pulled it. Found the mistake, made the fix, and put another 90,000 miles on it without issue and next to zero oil consumption between oil changes.........one of the really HARD lessons I learned early in this game that I never repeated.......FWIW......
__________________
If you can read this, thank a teacher. If you can read this in English, thank a Veteran! https://cliffshighperformance.com/ 73 Ventura, SOLD 455, 3740lbs, 11.30's at 120mph, 1977 Pontiac Q-jet, HO intake, HEI, 10" converter, 3.42 gears, DOT's, 7.20's at 96mph and still WAY under the roll bar rule. Best ET to date 7.18 at 97MPH (1/8th mile), |
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#112
08-06-2023, 10:05 PM
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Just last year the machine shop installed the rods backwards to the pistons ala Chevrolet and had to reheat/press out / install the correct way.
The conversation went, "chamfer backwards at crank with piston notch correct". He said" it will be OK, we do that like all Chevys and Fords". I said " Nope chamfer correct, notch correct and you can't change piston locations to correct this because you balanced it and I paid for the pistons in correct relationship with crank, right?" "Right" |
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#114
08-06-2023, 11:24 PM
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Was the engine in question using oil? I would leave the short block alone if it is ok.
I have honed out a ton of 10K mile engines that were using oil, that had the correct piston orientation, honed them, with new rings, and then the oil consumption stopped and ran for years. Sometimes the rings do not brake in correct or bore are not straight after engines are bore out. I have hung Pontiac pistons on backward, and done other brands also, I never remember one using oil? Maybe I am just lucky, but I have done a lot more than one engine with the pistons reversed, several 455 Pontiacs too.. I reverse hung the pistons to reduce the force on the piston skirt on the thrust side. Especially on cast pistons in performance builds. These days, with modern pistons, there is no offset most of the time, I don’t even think of it. Last edited by Jay S; 08-06-2023 at 11:36 PM. |
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#115
08-07-2023, 04:20 AM
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Offset piston pins reduce piston slap and decrease thrust load, NOT the opposite.
Reverse the pistons and youŽll get piston slap and increased load on thrust side. |
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#116
08-07-2023, 04:34 AM
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I want to build this motor correctly, since the notch is in backward and my Pistons have Valve reliefs on both sides, orientating the notch forward is the way to go. I will be sure to orientate the Rods correctly as well with your help. Thank you for correcting this problem early on in the conversation. So, now this means I have no choice but to pull the Main Caps and the Piston Bearings to micrometer them and plaster gauge the Journals to Bearings. This is a good indication of the miles on this Engine at this time. We will see if the Crank needs polishing or turning? This means I will purchase the new Rings and Bearings for a fresh build, one I can depend on for years to come. I just finish rebuilding the TH 400 Trans. and it is like new now. I won't skimp on this motor either.
I have the necessary tools in my full Snap-On box, Ridge Reemer, Ring Compressor, Hone tool, Ring sizer, etc... It is time for me to experiment and learn like I just did with the TH 400 Trans., that I am proud to say "works like new". We just cleaned the Pistons tonight and took photos, soon to be published online. We recorded some information on paper to speed up the process. We think that the Pontiac Water Jacket Mod has started, not sure since I have not read about the Mod. in some time, I must look back soon to refresh myself how that works. Something about blocking off some water Jackets and drilling holes in the Head or Block in order to get the water to raise from the Block up into the rear of the Heads and then out the water pump without sinking back down to the Block prior to flowing out the water pump and then to the radiator? I want to get this mod. rite! Here is what I have today for photos... |
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#117
08-07-2023, 04:43 AM
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More photos to come...
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#118
08-07-2023, 04:49 AM
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More photos to come...
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#119
08-07-2023, 04:54 AM
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More photos to come...
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#120
08-07-2023, 05:18 AM
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One more picture of the Cylinder Bore measured @ the top, middle and bottom of each Cylinder. We measured the approx. Stroke and the legend depicts the Head Bolts, Coolant passage open and closed with a plug. The closed ones mean that someone has been into these Heads doing the Pontiac water Jacket mod. I think. The Head Gaskets look like they were installed in 1968, one year after the Motor was cast from the factory. We on the PY forum believe that this motor was modified after the original sale, we don't know if the Engine was ever installed in a Vehicle or not. Since I have additional #'s and letters scribed into the pass. side left Head area in front, conscientious is that the owner at that time purchased over- the- counter, the Tri-power Intake Manifold and Carbs., plus Installed the 1956 Tri-power Cam as the racers would do in those days. Since the 1967 Pontiac 428 ci Engine should have the Quadra jet Carb. and the 4bbl Intake Manifold plus the 066, 067 or 068 type Cam. I was told upon buying this 1967 Pontiac TA with the 1967 Tri-power 428 ci HO engine was taken out of a wrecked truck that went over a mountain in the Carolinas while Bootleggers were on the job.
P.S. I don't see any water passages that are closed off on the Heads, perhaps all the necessary work was done at the Block, if that is at all possible? I need some research on this point. Someone knew what they were doing with this particular Engine, perhaps a race car drive? Otherwise, how did this Motor end up shining? Last edited by TRADERMIKE 2012; 08-07-2023 at 05:30 AM. |
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