Figured I would post this for reference here. I took a picture of a 1.5(stock) ratio rocker and a 1.6 ratio rocker arm side-by-side the other night while I was installing a set in my 1993 GP. I get them from my junkyard for $30($28 + $2 or so w/ tax + an environmental fee they tack on), so I figured "why not?" even if it's only adding maybe 2hp(that's what desktop dyno says the max gain is, it's a pretty consistant 1-2hp gain in the upper rpms supposedly) to my naturally aspirated 3.1. :laugh: There are maybe 7-8 or more sets of these rocker arms left in the pull-a-part junkyard I go to if any of you guys are interested. I probably won't go back up there for a few more weeks though.
(http://i44.photobucket.com/albums/f14/platjblser/rocker_comparison.jpg)
These rocker arms come from 1994 to 1995 year model cars equipped with 3100's. If your junkyard doesn't have years posted on the cars there, just look at the Vin #'s. The 10th digit will be "R"(1994) or "S"(1995) on the cars that have these rocker arms. You will need to get the pushrod guide plates from the 94-95 3100 along w/ the rocker arms... also take the pivot balls w/ the rockers, but inspect them for any gouging, etc. beforehand. I ended up using my stock pivots because they appeared to be in slightly better shape despite having twice the mileage on them. The 3100 studs vs. our stock ones are slightly different(the threads on them are about 1/8'' longer, and they have extended tips on top of them. Our stock studs put the rocker arms in the same exact place as they would be in w/ the 3100 style studs.
Just another picture of the rockers installed in the front of my '93 GP.
(http://i44.photobucket.com/albums/f14/platjblser/1.jpg)
EDIT: Here's a picture of a rocker arm stud from a 94-95 3100.
(http://i44.photobucket.com/albums/f14/platjblser/IMG_1380.jpg)
I also wanted to mention that I did some *VERY* crude measuring on these rockers and came up with approximately a 1.46 ratio for the stock ones and approximately a 1.57 ratio for the 94-95 rockers. It was a bit tough eyeballing measurements with a tape measure(I have some micrometers and calipers, just was too lazy to walk outside at this hour of the night/morning). :laugh: .
Here's a picture of how to measure rocker arm ratios I borrowed off of some random site.
http://i44.photobucket.com/albums/f14/platjblser/rocker_ratio.jpg
EDIT(yet again): Just wanted to say that the installation on my car at least was practically free. I already had the blue "permadry" rubber Fel-Pro valve cover gaskets installed in my car(they're very durable and can be reused, just slather a small amount of rtv on the little tabs that go where the heads and lower intake mate up). I also used blue rtv to seal the front coolant pipe just to the left of the front valve cover. I would have bought a gasket for it, but rtv works just as well as long as you dry off the surface and clean it pretty well(I've had blue rtv there for the past 140,000 miles ;) ).
Torque Specifications:
Rocker arm nuts - 18 ft-lbs
Rocker Arm studs - 47 ft-lbs(this is the specification for a 94-95 3100, the studs are identical in size to our 3.1 studs, so I used this specification and I'm 99% positive it's the proper specification for a 3.1 Gen II engine anyways. If you can, you can set your torque wrench to 47 ft-lbs before removing a stock stud and confirm the torque specification.)
Rocker arm cover(valve cover) bolts - 89 inch-lbs(key word here being INCH)
Nice writeup Matt, I did this install on my TGP back in the spring. While I had it all apart I replaced the pushrods with Federal Mogul units. Only an extra $20 spent.
Excellent write-up and information! Thanks much Matt! :thumb:
So which ones have the roller tip?
Quote from: TGPilot on October 04, 2006, 11:19:15 PM
Excellent write-up and information! Thanks much Matt! :thumb:
So which ones have the roller tip?
Roller tipped rockers are aftermarket only(from Crane, I think they require the old 2.8 style studs and a little grinding on our pushrod guide plates in order to work).
I also forgot to mention in my initial post that the rocker arm nuts on our cars should be torqued to 18 ft-lbs.
from 1996 +, a full roller valve train was used. :icon_mrgreen:
Quote from: GPChief on October 05, 2006, 01:39:35 PM
from 1996 +, a full roller valve train was used. :icon_mrgreen:
Not entirely true. ;) Roller
fulcrum rockers are used in 96+, not full "roller" rockers.
Thanks for the clarification!! ;)
Quote from: GPChief on October 06, 2006, 11:00:43 AM
Thanks for the clarification!! ;)
You're welcome. :cheers: BTW, which rockers are you running? I seem to remember you posting about 1.6's before...maybe the Crane or Comp roller tip ones?
I currently have the comp cams 1:6 in my TGP but I got a little happy with boost / low octane and my rings are shot (AKA when I hit boost my dipstick blows out of its holder) and it smokes like the dickins. For the short time before I did major engine damage I noticed a good differance on the top end.
I recommend the 1:6 to all, as a matter of fact I'll be putting them in a TSTE that I got recently. For ease of use I'd use the factory ones, adjusting the comp cams ones was a PITA.
I thought you had to change the guide plates when swapping to the 1.6 rockers. Mine seemed like they were going to bottom out in the guide plate so I switch them to the 3X00 ones.
Quote from: skalor on October 21, 2006, 10:50:51 PM
I thought you had to change the guide plates when swapping to the 1.6 rockers. Mine seemed like they were going to bottom out in the guide plate so I switch them to the 3X00 ones.
When I checked, my stock guide plates looked to have plenty of clearance. I will however pull the front cover off my '93 GP today to inspect the guide plates for any signs of rubbing now that I have ~500 miles on the rocker swap + multiple WOT runs. It only takes a minute or two to pull the front cover anyways. I'll update this post sometime today. I do have the 3100 guides laying around *if* needed.
EDIT: Ok, I checked the guide plates and they were indeed rubbing. They were touching the bottom just barely, but they were rubbing the sides of the guide plates pretty good(only on one side of the guide, I'll edit this again tomorrow with a picture or two). I had both sets of guide plates from the 3100's in my garage and had nothing planned today, so I went ahead and swapped the guide plates over on both cars. Live and learn I guess...and waste a good chunk of time in the process(took me right around 1.5hrs to swap them out on both cars, 30mins for the fronts on both cars...the other hour spent on the rears) . :laugh: Sooooo, grab the 3100 guides if you pick up these rockers. You *could* grind out the stock ones, but if you've already pulled the rocker arms from a junkyard, you might as well spend another 5 minutes and go ahead and get the proper guideplates along with them, they'll save you a lot of time grinding the stockers(you'll be there a while unless you have a air die grinder or something similar w/ a small carbide burr style bit). I swapped out the guide plates w/ both manifolds installed again...which makes it tough to access the rear bolts. For the typical DIY'er, you're going to want to go ahead and get both intakes out of the way so you have a clean angle of attack on the rear bolts. I updated my first post so that anyone reading will know to get the 3100 'plates now for sure.
Matt,
Good info, I'll try and remember to take some pics of mine (ground out the old guides) when I get the old engine out. I drove from TX to CO & other places so I've got about 2-3K on mine.
Thomas
damn i wish i would have read this thread before going to Colorado the other day. on the way home from Kenny's shop i stopped by a j/y in Denver and picked up a set of 1.6 rockers from a '94 3100. i got the rockers, pivots, and pushrods but didn't even think the guideplates would be needed :bash: oh well, the whole set cost me $3.50 so i can't complain. i wasn't even really planning on getting them until i spotted a '94 Corsica with the front valve cover removed. initially i figured i'd just forget it since i didn't think i'd have time to get the rear rockers out before the place closed, but then i found a '94 Cutlass with the 3100 laying on the ground next to it. so my front rockers are from a '94 Corsica and the rears are from a '94 Cutlass :laugh: both engines were '94 L82s (with the black plastic valve covers) so i'm sure they are the same.
so which pushrods do i use? i compared the '94 3100 pushrods to some pushrods i took out of a car with a GEN-II 3.1 that was all torn apart and either the intake or exhaust pushrod is longer than the other (can't remember which at the moment). the other pushrod looked like it was the same length.
Josh,
I used the same length pushrods, just upgraded to hardened ones.
HTH,
Thomas
cool, so i'll be fine just re-using the pushrods i have in my engine now?
i'm gonna have to see what the dealership charges for pushrod guideplates on Monday. i don't want to tear into another 3100 just to get those ecspecially when the junkyards around here would probably charge me too much to be worth the hassle anyway.
i guess if anyone has some '94-'95 3100 pushrod guideplates laying around let me know. i'm not going to grind mine up.
thanks for all the info everyone :)
I had to buy new guidplates a few years ago for a 3.1L. I wanna say they were like $4-5 a piece from the dealer. So, $24-30 for a set of 6.
Quote from: Robby1870 on November 23, 2006, 12:45:12 PM
I had to buy new guidplates a few years ago for a 3.1L. I wanna say they were like $4-5 a piece from the dealer. So, $24-30 for a set of 6.
cool thanks Robby. i'll just plan on doing that then. hopefully the '94/'95 3100 pushrod guidplates aren't much more expensive.
Josh, I think one of my friends has a set of 3100 guide plates laying around...I'll check with him when I get at chance. If not, I can get you some from a junkyard here next time I go.
Quote from: mfewtrail on November 24, 2006, 11:57:36 PM
Josh, I think one of my friends has a set of 3100 guide plates laying around...I'll check with him when I get at chance. If not, I can get you some from a junkyard here next time I go.
awesome, let me know
thanks Matt
I just took the time and a couple of round files (course / Fine) and made my slots bigger. I made sure there was at least 1/4 inch free play and called it good. I'll let you know if there was any ware when I tear my motor apart.
just wondering, is it absolutely necessary to remove the intakes to swap these in? if i can get by without doing that that would be great. i would probably just remove the alternator & bracket, undo the dogbones and pull the engine forward, and then get the MAF sensor, canister purge solenoid, and throttle cables out of the way.
also, does the lifter have to be on the base circle of the camshaft (valve closed) when torquing the rocker arm nut down to 18 ft/lbs? or does it even matter?
TIA, i want to get this done before i head to the strip in April. i'll probably be doing it the same time i install the injectors, so i guess the plenum would be off anyway possibly giving me some more room to work with.
Quote from: TurboSedan on February 16, 2007, 04:37:29 AM
also, does the lifter have to be on the base circle of the camshaft (valve closed) when torquing the rocker arm nut down to 18 ft/lbs? or does it even matter?
YES! Piston must be at TDC otherwise the increased spring tension won't give you a proper torque reading and the rocker will be loose once the spring tension's less (ie when the cam rotates). This parts a huge pain in the ass and once you do it once you should go through it again and make sure you didn't miss anything before you put it all back together.
I'm sure there are ways to do it with the LIM still on, but most of the rear bank is a bitch to reach and I couldn't even get a ratchet on a coupe of the nuts because the LIM was in the way. Had to take mine off.
Quote from: GutlessSupreme on February 16, 2007, 08:24:44 AM
Quote from: TurboSedan on February 16, 2007, 04:37:29 AM
also, does the lifter have to be on the base circle of the camshaft (valve closed) when torquing the rocker arm nut down to 18 ft/lbs? or does it even matter?
YES! Piston must be at TDC otherwise the increased spring tension won't give you a proper torque reading and the rocker will be loose once the spring tension's less (ie when the cam rotates). This parts a huge pain in the ass and once you do it once you should go through it again and make sure you didn't miss anything before you put it all back together.
that is what i did before when i replaced the LIM gasket and then had to do it again when i broke the timing chain. i made sure the lifter was on the base circle before torquing the rocker nut. i just wanted to be sure that was required with the 1.6 rocker/pivot balls.
Quote from: GutlessSupreme on February 16, 2007, 08:24:44 AM
I'm sure there are ways to do it with the LIM still on, but most of the rear bank is a bitch to reach and I couldn't even get a ratchet on a coupe of the nuts because the LIM was in the way. Had to take mine off.
yeah, i'll just take it off. been there done that before anyway. oh well.
thanks Tony
It's just plain out easier to remove the lower intake to do the rear rocker arms Josh. I swapped mine without removing the upper or lower intakes, but that was a total pain in the ass to be honest(it was rough getting on those center rocker arms, I had to do some clever rigging with a variety of tools I have here :laugh:).
EDIT #??(I lost count). I edited this because I thought I sounded like a smart ass with one of the replies I had typed up here earlier. :icon_redface:
Anyways, our rocker arms are not adjustable(they're a "net lash" setup), so it isn't necessary to rotate the engine so that the lifter sits on the base circle of the camshaft before torquing the rocker arms. Simply remove the old rockers, slap the new ones on and torque them to spec(18 ft-lbs). You'll notice that when you get to 18 ft-lbs, that the rocker arm nuts will have bottomed out on their corresponding studs. I can post videos of my engines running perfectly if you guys need anymore reassurance about this... :laugh: or you can search around w-body, 60*V6, etc. as this has been covered quite a few times.
Quote from: mfewtrail on February 16, 2007, 08:24:19 PMAnyways, our rocker arms are not adjustable(they're a "net lash" setup), so it isn't necessary to rotate the engine so that the lifter sits on the base circle of the camshaft before torquing the rocker arms. Simply remove the old rockers, slap the new ones on and torque them to spec(18 ft-lbs). You'll notice that when you get to 18 ft-lbs, that the rocker arm nuts will have bottomed out on their corresponding studs. I can post videos of my engines running perfectly if you guys need anymore reassurance about this... :laugh: or you can search around w-body, 60*V6, etc. as this has been covered quite a few times.
If you say so.. but I'm telling you mine would end up loose if the piston wasn't at TDC.
Quote from: mfewtrail on February 16, 2007, 08:24:19 PM
Anyways, our rocker arms are not adjustable(they're a "net lash" setup), so it isn't necessary to rotate the engine so that the lifter sits on the base circle of the camshaft before torquing the rocker arms. Simply remove the old rockers, slap the new ones on and torque them to spec(18 ft-lbs). You'll notice that when you get to 18 ft-lbs, that the rocker arm nuts will have bottomed out on their corresponding studs. I can post videos of my engines running perfectly if you guys need anymore reassurance about this... :laugh: or you can search around w-body, 60*V6, etc. as this has been covered quite a few times.
just wanted to say that way works fine (not that i doubted you :laugh: ) i tightened them all down to spec with no regard to camshaft position. i could feel each one bottom out before i hit 18 ft/lbs :thumb:
i just started it up for the first time since May. started right up and seems to run great. new owner takes it tomarrow and then its replacement will be in my garage on Monday lol. i didn't bother installing the 1.6 rockers since i still didn't have the guideplates. oh well. thanks again Matt.
yeah I'll confirm what Matt said there. During my rebuild the manual stated 18 ft lbs was the correct force on the rocker nuts.
Compared to the 86 4.3 C1500 engine I rebuilt, the TGP rockers were simple. Those needed adjustment. Our 3.1s do not require that.
great right up!!
Quote from: mfewtrail on February 16, 2007, 08:24:19 PM
It's just plain out easier to remove the lower intake to do the rear rocker arms Josh. I swapped mine without removing the upper or lower intakes, but that was a total pain in the ass to be honest(it was rough getting on those center rocker arms, I had to do some clever rigging with a variety of tools I have here :laugh:).
EDIT #??(I lost count). I edited this because I thought I sounded like a smart ass with one of the replies I had typed up here earlier. :icon_redface:
Anyways, our rocker arms are not adjustable(they're a "net lash" setup), so it isn't necessary to rotate the engine so that the lifter sits on the base circle of the camshaft before torquing the rocker arms. Simply remove the old rockers, slap the new ones on and torque them to spec(18 ft-lbs). You'll notice that when you get to 18 ft-lbs, that the rocker arm nuts will have bottomed out on their corresponding studs. I can post videos of my engines running perfectly if you guys need anymore reassurance about this... :laugh: or you can search around w-body, 60*V6, etc. as this has been covered quite a few times.
I will also vouch for this being true. I did the 1.6 rocker swap this spring without rotating the cam, just bolted in the new rockers. I drove the car 1,043.5 miles this last summer with no problems.
Just a quick question. If I do the 1.6 rocker swap on my 89 TGP and go with the LS1 springs update and cam change, will I still need to modify my guide plates? Also, does anyone know where I can get a set of the 1:6 rockers and if so how much? Thanks for all the useful info I find on these forums. How anybody figured this stuff out in the first place is amazing. Who woulda thunk it! :icon_razz:
I could get you a good used set pending your location. PM me if you're serious.
i still have to install these on my 3.1 car... been sitting around for ever!
Hey All! Just recently got the upgrades done to the TGP. I put in a Comp Cams H260 cam, new lifters, timing chain and gears. Also put in 1:6 steel rockers, LS1 valve springs, and 22# injectors. Also put in a 180 degree thermostat. However, car runs horrible. It ran better with a skip on #5 cylinder and the cam lobes worn down. :damnit1: Have not had a chip made for it yet as I am not sure if there is a mechanical problem. Car seems to idle slightly rougher than before but actually sounds pretty good with a little more thump coming from the cam. When you accelerate from a stop the car seems to have half the power it had before and when you floor it it starts bucking and it sounds like it is backfiring through the turbo. Rapid bucking and misfiring and no power! :icon_evil: Is it possible that with the 1:6 rockers that new rocker studs are needed to enable valve adjustment or do you just torque the valves down till they bottom out as before? I have read posts on this before and all seem to say you torque the rocker arms down as if they were the original 1:5's. If it doesnt matter which rocker arm you have in terms of rocker torque/adjustment, if you change the cam to a bigger cam, would this require manual valve adjustment? Also, car shows check fuel on the DIC. Checked fuel pressure and it was good. Please help as I am ready to set it on fire and be done with it!
Sounds like the valves are not closing all the way.. Just a guess
i would first do a compression test make sure all the cylinders are good. check for codes via paperclip method. Make sure the plugs are on in right order 146325. That should get you on the right track.
Checked the plugs and wires.They are in the right order and good. I am thinking valve issue also. When I was installing the valvesprings, the cylinders held pressure as I used compressed air to remove the valve keepers without removing the heads. However with the cam and the 1:6 rockers, maybe the valves are'nt closing all the way under load. I wonder if the valves can be manually adjusted using the current rocker studs and if it is even required to manually adjust them. Most people on the forums seem to have installed them and it was a turnkey modification. Thanks for your input. :twitch:
Are we limited to just the 94-95 3100 rockers? I have had a set of roller rockers from a 2000ish 3400sfi, will those work or will that involve a lot of work? I'll try to get pics up of them soon
Those rocker arms will only work w/ the later model heads. There are aftermarket "roller tip" rockers available that will work with the stock heads though. Check out the 60degreeV6 store and forum to find info on those...