BUILD THREAD JRP's '87 Regal Thread

[MrSony]

So I did get over to the machine shop today. The freeze plugs and all the pipe plugs have been installed in the block. Bob began installing the cam bearings and got 4 of the 5 in, however there is a slight casting defect in my block that made it difficult to get the #3 cam bearing into place, and the bearing ended up deforming when he started pressing it in. He used a couple standard Buick 350 cam bearings to experiment and rectify the issue, and once he had it figured out he ordered another TA bearing, so we're hung up waiting on that cam bearing before the bottom end can go together. The cylinder heads have been mocked up a couple times and are just about ready to go. Mike tapped the holes for heated choke so that they can be blocked off with pipe plugs. That'll keep the intake temps cooler and they aren't needed anyway since I'm running an electric choke. Also when the cylinder head was mocked up, Mike said the aftermarket TA stamped steel rockers didn't seat on the valve tips quite the same way the factory ones are supposed to, and because of that they "drag" across the tip of the valve stem. His concern with that was longevity of both the rockers and the valve stems. So I'm looking into the TA roller rockers which would eliminate that issue and are also a 1.60 or 1.65 vs a 1.55 ratio rocker which would allow for some more lift. So that's the update for right now.

Cool beans. Yeah, core shift is an issue with some Buick stuff, but that goes without saying really. GM was real lazy in the 70s. And those head holes I think you're referring too are just the exhaust crossover, good he blocked them. I left them open, cause I drive my car in -25f. 😛

Look on TA's FB page, they posted a video of the first start with the AL heads! 10.6:1, high rise intake, 780 holley, they're hoping for 500hp NA. Dyno results in a week or two. I'm betting it will at least be 425.

PS: you can swap your '76 rockers on to your '72 engine. I did, no issues. TA has rocker buttons, order 2 bags. Only 16 per bag, no room for error. That's if they'll solve your issue. I wouldn't spend $900 on a maybe fix.

 

[Texas82GP]

Love the attention to detail your engine builders are putting into this.

 

[joesregalproject]

Just found & read through this thread. Nice progress.

Thanks for following along, I appreciate it!

Love the attention to detail your engine builders are putting into this.

I do too. Bob and Mike have really done a fantastic job on every aspect of this engine, even the smallest little details. It's something I really appreciate.

PS: you can swap your '76 rockers on to your '72 engine. I did, no issues. TA has rocker buttons, order 2 bags. Only 16 per bag, no room for error. That's if they'll solve your issue. I wouldn't spend $900 on a maybe fix.

My '76 rockers are pretty worn which is why I was planning on using TA's stamped steel rockers. I really don't want to spend $900 on rockers either, but I also don't want to have to replace my valves in a few years because I was too cheap to buy them now. Plus there are other benefits, obviously less friction in the valvetrain, additional valvetrain adjustablity, they are more rigid, and the higher ratio is easy power.

 

[lilbowtie]

Joe be careful and do your homework - camshafts are designed w/ a certain rocker ratio, why second guess the engineers. It will take more to lift the higher ratio and make sure your springs don't coil bind (.030 more lift/1.65). With the changes you have made you might need different push rods for correct valve train geometry.

 

[joesregalproject]

Joe be careful and do your homework - camshafts are designed w/ a certain rocker ratio, why second guess the engineers. It will take more to lift the higher ratio and make sure your springs don't coil bind (.030 more lift/1.65). With the changes you have made you might need different push rods for correct valve train geometry.

Thanks for the heads up. The TA cams are designed to work with both stock rockers or the TA roller rockers so there should be no issues regarding rockers. Mike did an extensive amount of work to ensure that the valve stem heights are all at the factory spec so that I would retain the same valvetrain geometry, so stock pushrods should be okay. If there are any issues, they should become apparent during mock up. Correct valve springs are something I will leave up to Bob and Mike. They should have no problem finding a spring that meets the spec. I believe the cam calls for a spring that puts 110 lbs on the seat, and something like 275 or 280 lbs compressed.

 

[MrSony]

I wonder if the "go-to" GN springs will be a good fit, the comp 980-12. 980-16 is the V8 part number, 16 for 16 springs. I bought a set, but they require the valve guides be cut for the seals so I never used them. They were identical in every dimension to the stock springs, but have a damper.

 

[MrSony]

Thanks for following along, I appreciate it!



I do too. Bob and Mike have really done a fantastic job on every aspect of this engine, even the smallest little details. It's something I really appreciate.



My '76 rockers are pretty worn which is why I was planning on using TA's stamped steel rockers. I really don't want to spend $900 on rockers either, but I also don't want to have to replace my valves in a few years because I was too cheap to buy them now. Plus there are other benefits, obviously less friction in the valvetrain, additional valvetrain adjustablity, they are more rigid, and the higher ratio is easy power.

Worn how? You can buy individual replacement rockers, and surprising to hear the new shafts and whatnot you ordered are off, never heard anything about that. Have you contacted TA about it? The roller rockers are made to "bolt on", so if you have an issue with the new stamped, you will probably have that issue with the $900 gamble rockers. Your engine guy may be able to modify them to shift the rockers over a few thousandths to fix it. Also, there are RIGHT and LEFT rockers. The aluminums are marked as such. On The stamped, the pushrod cups are ever so slightly offset. Maybe he accidentally put em on wrong? Or do they come assembled? The pic showes them all apart.
Just a thought.

 

[joesregalproject]

Worn how? You can buy individual replacement rockers, and surprising to hear the new shafts and whatnot you ordered are off, never heard anything about that. Have you contacted TA about it? The roller rockers are made to "bolt on", so if you have an issue with the new stamped, you will probably have that issue with the $900 gamble rockers. Your engine guy may be able to modify them to shift the rockers over a few thousandths to fix it. Also, there are RIGHT and LEFT rockers. The aluminums are marked as such. On The stamped, the pushrod cups are ever so slightly offset. Maybe he accidentally put em on wrong? Or do they come assembled? The pic showes them all apart.
Just a thought.

The rockers are worn where they contact the shaft, and where they contact the valve tip.

The new rocker shafts themselves are okay, the issue is with the replacement rockers. Hard to explain but if you look at a stock rocker and one of the replacements side by side, they are different. The replacement rockers are not a true 1.55 ratio rocker like the factory ones were, they are less. The roller rockers are true to their advertised ratio. The issue is with the way the rockers contact the valve tips. They are aligned dead center with the valve stem tips. But when they compress, the rocker slides across the whole face of the valve tip, as opposed to just pushing straight down on the middle of the face like it is supposed to. Over a short period of time, this will cause wear into the valve stem tips and the rockers themselves. The stock rockers didn't do this, but the TA rockers do. The roller rockers are more likely to push straight down due to being more rigid, but even if they don't, it's a non issue because of the roller. The was an issue that was only discovered during mock up, and it's why Bob does mock ups before just bolting it together and turning the key.

I'd rather it cost me $900 in rockers now, than cost me $200 in rockers now, and then have to pull the heads back off and cost me $1000 in machine work later to make new valves and still have to buy the $900 rockers later on.

 

[MrSony]

The rockers are worn where they contact the shaft, and where they contact the valve tip.

The new rocker shafts themselves are okay, the issue is with the replacement rockers. Hard to explain but if you look at a stock rocker and one of the replacements side by side, they are different. The replacement rockers are not a true 1.55 ratio rocker like the factory ones were, they are less. The roller rockers are true to their advertised ratio. The issue is with the way the rockers contact the valve tips. They are aligned dead center with the valve stem tips. But when they compress, the rocker slides across the whole face of the valve tip, as opposed to just pushing straight down on the middle of the face like it is supposed to. Over a short period of time, this will cause wear into the valve stem tips and the rockers themselves. The stock rockers didn't do this, but the TA rockers do. The roller rockers are more likely to push straight down due to being more rigid, but even if they don't, it's a non issue because of the roller. The was an issue that was only discovered during mock up, and it's why Bob does mock ups before just bolting it together and turning the key.

I'd rather it cost me $900 in rockers now, than cost me $200 in rockers now, and then have to pull the heads back off and cost me $1000 in machine work later to make new valves and still have to buy the $900 rockers later on.

I 'spose. And that's how the Buick rockers wear. Thats normal, not ideal but normal. You can still buy individual stamped steel rockers from the parts store, but thats probably what TAs stuff is anyway.

 

[joesregalproject]

Dropped off the timing cover off of my '76 motor as well as my distributor and both cam gears and fuel pump eccentrics. Bob is going to mock it up and make sure the distributor angle is okay on the aftermarket timing cover and the gears are meshing nicely. The snowstorm this week screwed up shipping so my cam bearing and some I my other parts haven't showed up.

I 'spose. And that's how the Buick rockers wear. Thats normal, not ideal but normal. You can still buy individual stamped steel rockers from the parts store, but thats probably what TAs stuff is anyway.

I talked to Bob and Mike about this a little more in depth today, and Bob was able to illustrate the issue really well on a mocked up motor. The issue of the rockers sliding across the face of the valve tip from the intake side to the exhaust side as it compresses not only wears into the face of the valve tip, but it also flexes the valve stem back and forth and will cause stem wear and guide wear. The roller rockers roll vs sliding, and the lateral travel across the face of the valve tip is also about 1/3 of the travel of what the stamped rockers would be. I hope I'm making some sense here, it's kinda hard to describe in writing.