[Cliff R]

To date I've never once assembled a Pontiac engine using offshore "H" beam rods without having to do some work to them.

I've even had folks bring engines here bored, machined, and ready to assemble. They had bought "kits" for them and every single time I rejected some of it, all of it, or at a minimum had to work on something with the connecting rods. Once I remember the pistons being WAY too short and ended up nearly .050" in the holes at TDC. That particular build was when a West Coast Pontiac shop was closing up and most likely dumping some parts on the market that didn't make the grade.

I keep a small ball hone in the tool box to open up the small end of the Chinese "H" beam rods to get the pins to slide thru them. Usually that's not really a big deal but required before assembly.

I always found it quite interesting that folks buy "balanced" spinning assemblies with Chinese cast steel crankshafts, no-name pistons, and rods in that "goofy" Chinese cardboard and wrappers that have NEVER been open but supposedly it's all balanced and ready to assemble.....duh? I woln't mention who supplied them but they came from one of the "big" shops that specialize in Pontiac engines.

Matters not in the big scheme of things as it's up to the person doing the final assemblie to make sure everything is spot on and within tolerance. So being meticulous and attention to detail is REQUIRED with these things. It's a pretty rare occassion when you can just get all you parts rounded up, checked, cleaned, painted if/as needed and do the entire assembly in one sitting. You are ALWAYS going to run into a problem someplace, like one bearing shell miss-marked and .005" thicker than all the others, or the oil control expander rings butting hard together and needed clearanced, or "soft" piston rings that snap like twigs when you try to install them on the pistons, or the camshaft goes thru 4 bearings just fine and ceases up SOLID on the last bearing. There are other more minor issues you'll run into, like valve springs that aren't even close to the installed and open pressures compared to the literature sent with them at the correct assembly height, rocker arms that woln't fit under the covers without shortening up the lock-nuts or removing a little material from the pushorod end of them so the don't "rub" the covers even with a taller gasket in place.........so a "turn key" set of parts and assembly with out issues is about as rare as the winning Power Ball lottery ticket.........FWIW.........

[keith646671]

I have a number of Pontiac engines to put together hopefully. Since I have never broken a Pontiac rod and none of the 10 blocks I have, most with original rotating assy's have holes in the side I am somewhat skeptical they wont be adequate for my needs if reworked. I was planning on sending 2 sets for rebuild and cryo and having ARP bolts installed just to put on shelf as my stock replacements for street applications with a little safety factor. Bought the ARP bolt sets already, one set is for the early steel rods and one for the later iron rods. I know earlies are not popular, mine are heated treated and I remember climbing 6 high in junkyard to find em I will use. Thinking my 66 Star for street duty. Just made a friend at Starrett(we went to HS together) he is working a 84-111-4 bore gauge for me, I plan to use to get accurate readings on oil clearance, taper on rods and mains and cam bores .. my stuff will come through 1 of 2 top level shops where things should be dead on but "I'll just check" and log what I find when I put together. Bought Rehrer-Morrison book( text for their class) on engine assy. Not sure it is as in depth as I wanted concerning bearing clearances. I will say I have a set of 4340 CAT H-beams with ARP rod bolts that have been through both shops, and have been balanced to chromed Scat crank to under .001 front and rear per measurements I received. For an engine I intend to pound on alittle. I have billet main caps for my YK block(future) and also for a 92 4bolt sbc(this year) .. current poncho is cryo'd 2 bolt caps. Wondering 2 things ..
1. is there such an animal as billet replacement caps for
factory rods?
2. how important is it to keep same rod cap with rod as I have
several sets that are mixed up now

[mgarblik]

Originally Posted by keith646671

I have a number of Pontiac engines to put together hopefully. Since I have never broken a Pontiac rod and none of the 10 blocks I have, most with original rotating assy's have holes in the side I am somewhat skeptical they wont be adequate for my needs if reworked. I was planning on sending 2 sets for rebuild and cryo and having ARP bolts installed just to put on shelf as my stock replacements for street applications with a little safety factor. Bought the ARP bolt sets already, one set is for the early steel rods and one for the later iron rods. I know earlies are not popular, mine are heated treated and I remember climbing 6 high in junkyard to find em I will use. Thinking my 66 Star for street duty. Just made a friend at Starrett(we went to HS together) he is working a 84-111-4 bore gauge for me, I plan to use to get accurate readings on oil clearance, taper on rods and mains and cam bores .. my stuff will come through 1 of 2 top level shops where things should be dead on but "I'll just check" and log what I find when I put together. Bought Rehrer-Morrison book( text for their class) on engine assy. Not sure it is as in depth as I wanted concerning bearing clearances. I will say I have a set of 4340 CAT H-beams with ARP rod bolts that have been through both shops, and have been balanced to chromed Scat crank to under .001 front and rear per measurements I received. For an engine I intend to pound on alittle. I have billet main caps for my YK block(future) and also for a 92 4bolt sbc(this year) .. current poncho is cryo'd 2 bolt caps. Wondering 2 things ..
1. is there such an animal as billet replacement caps for
factory rods?
2. how important is it to keep same rod cap with rod as I have
several sets that are mixed up now

I will try to answer a few of your questions. 1. I am one of the few here that don't run screaming and hide in a closet when someone says they are going to use stock Pontiac rods in their build. If they are round, straight, and the correct size, they will be just fine for stock or mild street performance use. If the small ends are messed up, you will need oversize pins to use them. This will mean honing the pistons and the rods to restore the proper press fit. The new ARP rod bolts will make the assembly stronger than original. The old forged rods are also fine for the applications I listed above. I have raced them in NMCA class racing in 421's and 428's without issue . As far as mixed caps and rods go, the issue may be matching them back up for proper chamfer match on the sides. If you have a box of several sets of mixed rods and caps, it may be very difficult to match them back up for use. If they are mixed, but still in sets of 8, you can closely inspect each cap and rod and pay very close attention to the chamfers on the sides. You can usually get them matched back up if you spend some time inspecting them. Of course all the rods and caps will need to be cut and reconditioned to make them usable again. Good luck. Final note, there are no replacement aftermarket caps for connecting rods that I know of. You would not want dissimilar metals in the rod and cap anyway. The expansion rates of the metals may not be the same and cause distortion of the cap or rod or loosening of the fasteners.

[steve25]

Another important detail to look out for in terms of rebuilt rods is this.

Application of a chamfer as in this photo, or even any hint of a chamfer.

With a chamfer at the parting line you will loose some if not all of the needed bearing crush that keeps the bearings from spinning.

If you have rods with a chamfer just consider them junk.

[65madgoat]

ps. NOTHING will ever make an LS/LT more attractive =in= a real vintage Pontiac. EVER!

[keith646671]

Thanks Steve , Mgar .. token timed out on a longer post so will make this one short and sweet

1. Steve - Will check my rods and post photos for chamfer issue. Not sure I understand bearing crush real well. Know machine shop checked my Poncho 400-444 mod block with caps on and torqued, and rod bearings in and torqued so I could have crank ground to those dimensions + .0025 . Is it that bearings are not a perfect circle until "crushed" in place by torquing mains down? Will soon be able to check I believe with Starrett bore gauge as that is condition they are in now. Worried about disrupting Calico coating with bore gauge and being accurate with a gauge that is .0001, trying to get a machinist bud to help.

2. Mgar - Any thoughts on wisdom of using billet steel center 3 main caps with iron block now that I am now worried about ? Would think less of a bending force being applied to mains and a more solid oil clearance dimension might be helpful. Especially on the Chev with a skinnier spine. Have Pro-gram center 3 for Chev 350-316 mod and future YK 428 likely to stay 428.

[keith646671]

PS Happy St Paddy's !!

[steve25]

This same chamfer should be looked for in the main bore’s .

[mgarblik]

What kind of power are you planning to make with this engine? Also what RPM range?

[keith646671]

Have 2 blocks on stand now. Hoping for 400+ NET hp on both. Both bottoms capable of up to 15lbs boost. Poncho block machined, heads not, Chev block still needs to be, Fastburns near complete. Poncho 6-6500, Chev 7-7500RPM. Both full forged r/a.

Chev - Pro Gram 4-bolt center 3 caps ARP studs, Lunati "Chrome Crank"( modded factory DZ forged crank) .. 3.100 stroke 2.000 rod journals ... angle milled 53cc GMPP Fastburns-shaft rockers. Scat Pro Comp I-beam ARP2000. CC solid roller 268M-rev kit 224,224@.050

Poncho - Factory cryod 2-bolt caps ARP studs Scat forged crank - chromed 4.040 stroke 2.200 rod journals, CAT 6.900 4340 H-beams .. whole r/a cryo and balanced in AZ. Howards ft cam with new Rhoads, 411391-08 241,247@.050

Premium pistons for both. R+L Dover NH my local machine shop. Supposedly top notch if not best in NE. Hoping to install balanced r/a's in machined block at home without boogering. Learn what I can. Cooked up my own recipe for these 2 to see what happens. Likely conservative on Chev and whacko on Poncho cams, we'll see. Have hit several roadblocks in this process, hope to have both finished this year. Chev for 84 Cutlass stick, Poncho for 71 Formula 400 auto. Both mainly streeters but fun occasionaly at Epping. May replace current daily runner and backup(06 Lincoln, 94 Eldo) .. likely have to sell them to finish anyways.

[AG]

I use R&L in Dover and had good luck with them. Leo welded up a chamber in one of me heads that dropped an exhaust valve and machined it to be exactly like the rest.

[keith646671]

I like Leo as well and have for many years. He will talk, speculate and answer questions for a certain amount of time, which some others wont, but briefly as time is money for him, he's usually busy as a beaver He also knows and speaks with many in performance industry. A pro.