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View Full Version : Bolt-on Full Roller Rocker for Gen III



geoffinbc
04-02-2005, 02:10 PM
http://www.cranecams.com/?show=browseParts&lvl=3&prt=2059&action=partSpec&partNumber=144750A-16 Looking at these rockers for the LS1/LS6 and new Vortec engines I am pretty confident they will bolt onto a Gen III engine without modification to the lower intake manifold. If you notice there is alot of extra relief on the back of the rocker which would normaly hit the LIM.
http://members.shaw.ca/lloydcharvey/3.1to3400/cgrrr1.jpg
Its hard to see but the 2 rockers that are highest up are the ones that hit the LIM and clearancing the LIM is the only way to solve the problem. No while this task really isn't that hard it would be nice to have a simple bolt on.

So with the LS rockers you would get a 1.7 ratio which would be good for a bit more power. You can just order the rockers alone and then you would need to buy the crane conversion studs to convert the 10MM threads in the head to a 3/8 top. You would also need to aquire some Gen II guideplates in order to complete the install. This mod would also solve preload issues with reground cams.

Hopefully someone will try this one day.

Shaun41178
04-02-2005, 02:32 PM
Crane also makes ones for the 60 degree with the correct studs. $360. Its been done already.

And since they are adj would this solve all lifter preload with the reground cam? I dont' know

sharkey
04-02-2005, 02:37 PM
yes the adjustable rockers will make up for a regroung cam.

i wanst aware that crane made a full roller rocker set for the 60*v6. i know they make roller tips, but not a full roller.

geoffinbc
04-02-2005, 02:41 PM
No They do not fit. The reason I posted that is because the Crane rockers require modification to the LIM in order to fit. On Gen I and II the Crane rockers fit fine. On Gen III they dont. Trust me Lloyd and I are the first and I still think only ones to do the Crane Roller rockers on a Gen III. Also I have Installed them on Gen I and II aswell. Also on Gen III you need to add guideplates so you ahve to take them from a Gen II motor.

The advantage to the new LS series rockers is in the extra clearance on the back of the rocker. Also there is an increse in ratio from 1.6 to 1.7

LA1 Z24
04-02-2005, 10:57 PM
So is this all go...they def fit? or is this speculation?

Cliff8928
04-02-2005, 11:19 PM
The Gen III engines have guideplates for at least 2 years, so they don't HAVE to come from a Gen II


Cliff Scott
89 BerettaGT
04 AleroGX

Rhedalert
04-03-2005, 12:35 AM
very tempting, would be good for even a stock cam/engine for the ratio alone.

Shaun41178
04-03-2005, 01:19 PM
the modding of the lim that you are referring to is some grinding on the inside of the intake with a dremel to remove some metal. I don't see how that is such a big deal.

Also on later Gen 3 LIm's as far as I understand you dont' have to because GM emoved material from teh factory casting in these locations to make sure their own roller rockers dont' hit the lower intake mani. Thre are pics of the different lowers where some are notched and some aren't from the factory.

geoffinbc
04-03-2005, 05:01 PM
Man trust me I have done this. Yes GM machined a small amout of meterial from the later intakes but it is not nearly enough. The Crane rockers for the 60*V6 are very big and the back hits. You have to remove a good 1/8" of material from the LIM. It takes alot of time getting the right clearance and test fitting. Here is an intake ground down to fit the rockers.
http://members.shaw.ca/lloydcharvey/3.1to3400/intakemod.jpg This is the one Lloyd and I did. This intake had the GM machining done to clear the factory rollers but it is not nearly enough.

My Point is that the 60*V6 set from Crane needs modification to fit. However these new LS series rockers have a lot smaller back end on them so they should not need clearancing on the LIM. Then all you need are the correct studs (Which Crane, ARP and GM sell) and guideplates. This would make it a TRUE BOLT ON. Oh and it comes in a higher ratio.

The_Raven
04-03-2005, 06:54 PM
Just because the rockers are adjustabe, does not make them 'perfect' for not needing prper length pushrods.

Geometry will still need to be checked and verified. ;)

Any idea what the initial cost will be on these?

geoffinbc
04-04-2005, 12:16 AM
Figure $400. All Gold Race rockers are expensive.

Very true that they will not compensate for incorrect geometry. However it should suffice for a regrind.

Wolf
04-04-2005, 03:35 AM
. Then all you need are the correct studs (Which Crane, ARP and GM sell)
you wouldn't happen to have the part # for any of those

AaronGTR
04-04-2005, 02:19 PM
betterthanyou was the first, but not the only. ;) I was the second one to do this remember? He is correct that the ones designed for the 60v6 do not fit without modification. They come with the proper conversion studs to bolt onto the head, but they were designed for the inline valve head. So on the splayed valve head two of the rockers hit the lower intake manifold. I tried the route of grinding the manifold, but my rockers still wouldn't clear and I ended up going right thru the bottom of the runners. My solution was to grind a small radius on the top edge of the rocker itself. That is the part that hits, and you only need to remove a few mm of material to gain plenty of clearance. There is a lot of material there to work with so the integrity of the rocker is not compromised. It would certainly be nice to have a set of rockers that don't require moddification though.

He's also correct the adjustable rockers would solve problems with valve lash on a regrind. The stock pedastal style self-adjusting rockers are at a set height so you don't have to adjust valve lash when installing with stock parts. If you change something (cam base circle, valve stem length, etc) then the geometry would be off and you can't adjust it. With the new rockers you need the guide plates he mention though, and those still require custom pushrods. The stock GEN3's aren't heat treated and may fail if used with guide plates. The older pushrods are heat treated, but are a different length so they won't work. You may have to get a custom length too depending on what else you change. You just have to install the old length ones first and check the geometry to make sure the roller tip on the rocker stay in the middle 1/3 section of the vavle stem.

geoffinbc
04-04-2005, 03:10 PM
. Then all you need are the correct studs (Which Crane, ARP and GM sell)
you wouldn't happen to have the part # for any of those

Cranecams Part Number: 99148-2
ARP Part Number 100-7221 w/ 3/8" top
ARP Part Number 135-7221 w/ 7/16" top and 1/4" longer if you think you are badass and need a 7/16" stud :)

Then GM number is a mystery but I know they sold them to convert press in studs to threaded ones on the 4.3L. They did have a metric bottom. But who cares because you can get em from 2 other sources.

The_Raven
04-04-2005, 04:45 PM
. Then all you need are the correct studs (Which Crane, ARP and GM sell)
you wouldn't happen to have the part # for any of those

Cranecams Part Number: 99148-2
ARP Part Number 100-7221 w/ 3/8" top
ARP Part Number 135-7221 w/ 7/16" top and 1/4" longer if you think you are badass and need a 7/16" stud :)

Then GM number is a mystery but I know they sold them to convert press in studs to threaded ones on the 4.3L. They did have a metric bottom. But who cares because you can get em from 2 other sources.

How many studs come with those part numbers? 1? 2? I just checked my supplier and holy crap, cheapest one is $17 CDN,. hopefully that is a pair of them. Also do these part numbers include the nuts?

Shaun41178
04-04-2005, 08:05 PM
I stand corrected. Thanks

I guess I won't attempt this then with the regular Cranes. Guess I will just go with roller tip.

geoffinbc
04-04-2005, 08:43 PM
Raven 2 studs in a pack. The Adjusting nuts come with the Crane rockers.

Shaun what are you installing them on? Your Fiero in the sig? If so then the Cranes for the 660 will work fine but you have to blunt the corners on the rockers or they will touch the inside of the valve cover ever so slightly. I had to do it on my S-10 when I put Fiero Covers on it. If you are going it on a Gen III then just wait because I bet I know a guy who will be willing to upgrade to the new LS style rockers because they offer a higher ratio. ;) If they clear we will let everyone know.

Cliff8928
04-05-2005, 02:08 AM
With the new rockers you need the guide plates he mention though, and those still require custom pushrods. The stock GEN3's aren't heat treated and may fail if used with guide plates. The older pushrods are heat treated, but are a different length so they won't work. You may have to get a custom length too depending on what else you change. You just have to install the old length ones first and check the geometry to make sure the roller tip on the rocker stay in the middle 1/3 section of the vavle stem.

So you mean that even the '94-95 Gen 3 pushrods wouldn't work (they have guideplates)


Cliff Scott
89 BerettaGT
04 AleroGX

geoffinbc
04-05-2005, 12:12 PM
Yea they would. Even the self aligning rockers may still be heat treated. Who knows.

AaronGTR
04-05-2005, 09:49 PM
If they came with guide plates they are more than likely factory heat treated and should work. The older engines with guide plates were heat treated. As long as they are the right length for your app then go ahead and use them. I know the ones for the self aligning rockers weren't heat treated. I checked on it when I did my rockers. Only reason I had to order custom ones is because I have a '00 3400 and the pushrod length is longer than some of the older engines with guide plates. I couldn't find any stock ones the right length. It wasn't too expensive to get custom ones (just over a hundred dollars, can't find the receipt right now), and I planned on getting a cam and stiffer valve springs later anyway, so I got some nice high strength heat treated chromoly ones. :D A little over kill maybe, but I know I'll never have a pushrod fail.


I'll definitely keep an eye on this. I know some people on gagt.com who don't want to go to the trouble and expense of installing a cam but may be interested in a higher ratio rocker.

geoffinbc
04-06-2005, 12:26 PM
I went to a parts trade show last night. Everone in existance was there EXCEPT CRANE. I was so choked I wanted to see the damn things.

However there are some pretty good alternatives. Comp has some pretty small rocker arms that would most likely work. http://www.compcams.com/Technical/CurrentCatalog/HTML/311.asp

Check out the LS1/LS6 ratios they are 1.75 and 1.85. They are probabally cheeper than the Gold Race and are a nice alternative. Again judging by the back of the rocker they would probabally work without clearance.

bszopi
04-06-2005, 02:12 PM
They are actually quite more expensive. Did a search on Summit... The Cranes were $300 for 16 while the Comps were $490 for 16.

geoffinbc
04-06-2005, 02:16 PM
Ouch!! And WHY???

I would never pay more for cast than billet. Thats dumb. Ohwell Cranes look like the better answer to me then.

bszopi
04-06-2005, 02:26 PM
Oops... correction. The Crane's are $399 for 16. The Comp's are $32.99 each.

Not sure on the difference... BUT, Summit has 2 different models. There is the 144750A-16 which is just listed as 1.7 ratio rocker arms and then there is the 144750-16 (so, minus the A) which are the Pro Gold Race Rockers. That setup lists for $680.

oleman
04-06-2005, 04:17 PM
I have a 60v6 3100 in a corsica as a currently broken daily driver that I am in the process of overhauling.
Why are we spending all this money trying to get power from this turnip of an engine.
A small block chevy will be more reliable and have more streetable power than we will ever get with one of these 60v6 engines.
Daily driver maybe, hotrod at any reasonable cost, never.
Of course I am not too old to learn!!

bszopi
04-06-2005, 05:07 PM
Because anyone can make an SBC a hot rod. It takes thought, determination and ingenuity to make a 660 a hot rod.

RacerX11
04-06-2005, 06:47 PM
I have a 60v6 3100 in a corsica as a currently broken daily driver that I am in the process of overhauling.
Why are we spending all this money trying to get power from this turnip of an engine.
A small block chevy will be more reliable and have more streetable power than we will ever get with one of these 60v6 engines.
Daily driver maybe, hotrod at any reasonable cost, never.
Of course I am not too old to learn!!

Tell you what..go try to stuff a small block chevy into your Corsica, and when it is running and driven daily, come back and tell us just how easy and cheap it was to do.

Marty

hamondale
04-06-2005, 07:03 PM
Why are we spending all this money trying to get power from this turnip of an engine.
A small block chevy will be more reliable and have more streetable power than we will ever get with one of these 60v6 engines.


I think it's a nice package for small cars. I've seen Sprites like mine with V8's. They're nose heavy, overpowered, and hard to cool. Plus you need short legs or small feet. Look at http://tinyurl.com/5a92d
Would a SBC be better than my 3.4 in there?
H

geoffinbc
04-06-2005, 09:04 PM
Oops... correction. The Crane's are $399 for 16. The Comp's are $32.99 each.

Not sure on the difference... BUT, Summit has 2 different models. There is the 144750A-16 which is just listed as 1.7 ratio rocker arms and then there is the 144750-16 (so, minus the A) which are the Pro Gold Race Rockers. That setup lists for $680.

Crane sells a full kit to convert an LS1 or just a set of rocker with nuts. No guide plates or pushrods.

geoffinbc
04-06-2005, 09:07 PM
I have a 60v6 3100 in a corsica as a currently broken daily driver that I am in the process of overhauling.
Why are we spending all this money trying to get power from this turnip of an engine.
A small block chevy will be more reliable and have more streetable power than we will ever get with one of these 60v6 engines.
Daily driver maybe, hotrod at any reasonable cost, never.
Of course I am not too old to learn!!

A smallblock does not fit into everything. Plus there are alot of guys with V6's that will knock off a Camaro and they have far less money invested than the price of a Camaro. Then they drive home at close to 30MPG.

I would never touch an old smallblock for my truck. If I got anything it would be an LS1. Because like it was said before a smallblock is HEAVY and I already have bad weight distribution. Oh and a Smallblock is no more relaible than a 660. I have not had a single problem to date with my motor.

bszopi
04-06-2005, 09:07 PM
Ok. The price of the Comp one is the kit I think. But the rockers are still slightly more ($32.99 vs $29.99). Of course, they are also 1.75 vs 1.7 ratio.

geoffinbc
04-06-2005, 09:10 PM
I would still go for the Cranes. They are billet aluminum vs cast steel. That small of a ratio difference aint worth it. Or you can just jump to the 1.8 ratio :)

smilinguy99
04-07-2005, 03:29 AM
http://www.cranecams.com/?show=browseParts&lvl=3&prt=2059&action=partSpec&partNumber=144750A-16 Looking at these rockers for the LS1/LS6 and new Vortec engines I am pretty confident they will bolt onto a Gen III engine without modification to the lower intake manifold.

LIM interference isn't the only parameter that needs attention. The best lever arm length over the valve for geometry IS the Crane Gen I rocker. The length is 1.375". Typical SBC rockers will bolt up, but the geometry is a little off as the lever arm length is 1.40". I would suspect the lever arm length is 1.40" for these too. But I dunno.

By all means buy one or better yet, two rockers and test them. Just don't overlook other measures of fit.

sg99

smilinguy99
04-07-2005, 03:45 AM
I have a 60v6 3100 in a corsica as a currently broken daily driver that I am in the process of overhauling.
Why are we spending all this money trying to get power from this turnip of an engine.
A small block chevy will be more reliable and have more streetable power than we will ever get with one of these 60v6 engines.
Daily driver maybe, hotrod at any reasonable cost, never.
Of course I am not too old to learn!!

The V6/60 has some nice features that many folks on this board find quite useful. It is light, compact, durable and packs quite a bit of displacement in roughly the space of the average ricer motor. And if you are talking about a pushrod version, it is pretty simple too. Some folks with some pretty basic modifications have been able to drop their ETs significantly while those who have gone the turbo route have been able to get in the 12s pretty easily. Likely spending less money than your average ricer to do the same thing.

When making comparisons with this motor, think dollars, displacement, and available power per unit of weight. In these respects it compares favorably with smaller motors.

Of course, it does have some drawbacks. Except for a few bolt-on items, you are on your own. Personally, that's what I like about it.

sg99

The_Raven
04-07-2005, 02:00 PM
I have a 60v6 3100 in a corsica as a currently broken daily driver that I am in the process of overhauling.
Why are we spending all this money trying to get power from this turnip of an engine.
A small block chevy will be more reliable and have more streetable power than we will ever get with one of these 60v6 engines.
Daily driver maybe, hotrod at any reasonable cost, never.
Of course I am not too old to learn!!

With an attitude like that, the back button is your friend.....

Do a little looking around here, some members (myself included) have been able to get over 200 HP at the wheels for little money invested.

Other more extreme examples include The Cuman Bros 2.5L 660, making 350HP (IIRC) N/A, somone else that was making somewhere around 700HP from a turbo pushrod engine and GMs DOHC 3.9L (or was it 3.6L?) twin turbo engine making 1700HP.

I'm changing some parts on my engine and am shooting for 300+ HP at the wheels when it comes back out.

Then for my next chassis (AWD) I plan on making no less than 700HP at the wheels, all from less than 3.4L most likely 3.1L
Oh yeah the torque is speced out to be 550+ ft/lbs, so more than enough to move my 3200 lbs Jimmy down the track and around the corners. ;)

Cliff8928
04-08-2005, 02:27 AM
With all this talk of the increased ratios etc.. What's the limit on this for clearance on the stock components. How will it be affected with the 1.8 rocker on my 3400 with the stock springs, etc. Anyone know if there's potential for valve/piston clearance issues? Will the valve springs bind?



Cliff Scott
89 BerettaGT
04 AleroGX

geoffinbc
04-08-2005, 02:36 AM
I dont think anyone has ventured into that area. But even with a 1.8 ratio thats only .491 lift at the valve. Now this is just a guess but I believe you can even go over .5 a bit and still be ok. I know on the iron heads .5 is not a problem.

Springs are another story. That will have to be checked with a feeler guage.

Someones gotta do it all first. The parts are out there I guess its just a matter of time.

GinoBeats
04-08-2005, 10:32 AM
I have a set of the Crane Race Rollers 25759-12 1.6 Ratio I'll have to do some digging around and reading again but I thought it was a more or less drop in with the proper sized rocker studs.

geoffinbc
04-08-2005, 01:57 PM
What engine? On Gen 1 and 2 yes it is a direct drop in. On Gen 3 you have to clearance the intake manifold, get guide plates and heat treated pushrods.

GinoBeats
04-08-2005, 02:03 PM
Its for my '04 3400 I still have to order the valvetrain parts for the engine. I got my camshaft back in, it is a high lift unit as well.

geoffinbc
04-08-2005, 02:06 PM
Then you must modify the lower intake to fit the rockers. See pics above.

bszopi
04-08-2005, 02:58 PM
And you'll need 8mm studs versus the standard 10mm, since GM went to 8mm holes in the heads starting in 03.

GinoBeats
04-08-2005, 03:04 PM
Thanks guys, going to put all of the info together so I can prepare everything to be assembled and ready to go once my pistons come in.

geoffinbc
04-08-2005, 04:31 PM
And you'll need 8mm studs versus the standard 10mm, since GM went to 8mm holes in the heads starting in 03.

Thats ARP P/N 1347221 the bottom is M8X1.25 and the top is 3/8-24

Or if you buy the rockers that this thread has been talking about then they will come with all the studs you need. You know if Crane would get off their asses and just get some guideplates and different pushrods sell it in a 12 pack they would create a whole new product line for Gen III motors.

Cliff8928
04-09-2005, 03:06 AM
I dont think anyone has ventured into that area. But even with a 1.8 ratio thats only .491 lift at the valve. Now this is just a guess but I believe you can even go over .5 a bit and still be ok. I know on the iron heads .5 is not a problem.

Springs are another story. That will have to be checked with a feeler guage.

Someones gotta do it all first. The parts are out there I guess its just a matter of time.

I was just wondering if anyone ventured there yet. I would consider being the guinea pig for this project while i still have 2 cars around the house. So what should be done at a minimum?

-LS6 valve springs
-3.1 "T" valve seals (i think i have some extra from the 2.8, are they the same?
-Conversion studs?
-new full rockers for the "LS" engines
-Pushrod guideplates from 94-95 3100

Which rockers will most likely offer the best increase in performance? and are they adjustable, or do i need new pushrods?

sorry if I'm not doing most of the research on this one, I'm just strapped for time with work and stuff around the house (newest project, wallpaper removal)



Cliff Scott
89 BerettaGT
04 AleroGX

geoffinbc
04-09-2005, 02:56 PM
I would not use LS6 springs. Simply not needed. LS1 spring maybe.

Get conversion studs (M10 bottom 3/8 top)
Get requires valve seals if changing springs
Get Gen II or early Gen III guides
Early Gen III pushrods.
The rockers are fully adjustable I would go with the 1.7 ratio Crane Gold Race. They come with adjusting nuts.

mfuller
04-09-2005, 03:56 PM
I wonder if these new Crane LS series gold race rockers would work for me.....

I had Colin do up a set of heads for me recently, with LS1 springs and Viton valve seals, but I also had him mill the heads .020". The stock 1.6 roller rockers should work fine (stock cam), but would 1.7 Cranes be too much with my milled heads? I'm not smart enough to figure out if I'll have clearance problems with the extra valve lift.

geoffinbc
04-09-2005, 04:41 PM
You shouldn't have a problem but there is no way to tell for sure. You could go out and buy a cheepie stamped 1.7 rocker and test it out. Or if you have the engine apart then do the old playdough test on top of the piston and see how close a stock rockers comes and then you can calculate wether or not a higher ratio one will work.

Cliff8928
04-10-2005, 01:54 AM
I would not use LS6 springs. Simply not needed. LS1 spring maybe.

Get conversion studs (M10 bottom 3/8 top)
Get requires valve seals if changing springs
Get Gen II or early Gen III guides
Early Gen III pushrods.
The rockers are fully adjustable I would go with the 1.7 ratio Crane Gold Race. They come with adjusting nuts.

Well, why not use the LS6 springs? I'm in there, might as well... They're not that much of a difference in price. Also, the 1.8s might cause clearance issues?

I'll check the price on all that stuff next time I'm at work, and probably order it up.



Cliff Scott
89 BerettaGT
04 AleroGX

TurboZ24
04-10-2005, 02:37 AM
On the crane gold rockers on the Fiero valve covers. Mine fit under the stock Fiero covers without any clearance issues at all, even with the .62/.60" lift on the valve, still clear fine. I did have too clearance the rockers for the valve springs I run, but that was it.

geoffinbc
04-10-2005, 01:10 PM
Clif you just dont need that much spring pressure. It is a complete waste of effort and you are only going to create more valvetrain wear and loose power to the springs. Shit I dont think anyone has yet to prove the stock ones inadequate.

I did have to clear my fiero covers for the crane rockers on the tips because they touched the covers ever so slightly. I did it after I started the motor and could hear it. It was just a little bit of material I had to remove. Its not during lift it contacts, it is when the valve is in the closed position.

Stevesr
04-12-2005, 11:48 AM
Ok.I haven't been following this thread too closely,but this is the direction I am going with my Porsche V6 project but now you guys are confusing the hell out of me. I have a GenII block "94" 3100 heads and"00" intake manifolds. so I've got the guide plates,what else do I need to put these new rockers on my engine?

SteveSr

geoffinbc
04-12-2005, 12:12 PM
Studs. And of course the rockers them selves.

Stevesr
04-12-2005, 01:43 PM
Studs. And of course the rockers them selves.

So,with my 3100/3400 top end and these rockers I would'nt have to grind clearance on the LIM?

SteveSr

bszopi
04-12-2005, 02:22 PM
Well, that's what we aren't sure of. They LOOK physically smaller and able to clear the lower manifold without any grinding. But, until someone actually tries it, we won't know.

geoffinbc
04-12-2005, 04:20 PM
Well, that's what we aren't sure of. They LOOK physically smaller and able to clear the lower manifold without any grinding. But, until someone actually tries it, we won't know.

Agreed. I went to a few parts stores already to try and compare them but no one has any of the new LS Series in stock. Once I look at them I will be able to tell. I spend alot of freaking time looking at rockers for these engines.

Cliff8928
04-12-2005, 04:35 PM
I'll see if i can't order a set when i get into work today... Then i'll take pics and measurements.


Cliff Scott
89 BerettaGT
04 AleroGX

AaronGTR
04-13-2005, 11:48 PM
Clif you just dont need that much spring pressure. It is a complete waste of effort and you are only going to create more valvetrain wear and loose power to the springs. Shit I dont think anyone has yet to prove the stock ones inadequate.

I got it on good confidence from a GM engineer that the stock springs could get some minor valve float at high rpm (near the stock redline), especially if they have some miles on them and are starting to fatigue. Thats why I recommend if someone has a DHP pcm with the raised redline and they are doing heads anyway that they upgrade to the LS1 springs. The stock LA1 springs and LS1 springs have almost the same closed seat pressure, but the LA1 installed height is .1" shorter so the LS1 spring would be compressed more and have more initial pressure. That should be enough even for 1.7 rockers I think. I am using LS6 springs when I install my cam though because I will be running higher lift with a steeper ramp than stock. I don't think they will cause too much valvetrain wear with the roller lifters, full roller rockers, and heat treated chromoly pushrods I have.


Just for reference:
-stock LA1 springs, 75lb @ 1.701" closed, 230lb @ 1.26" open.

-stock LS1 springs, 76lb @ 1.8" closed, 220lb @ 1.32" open.

-stock LS6 springs, 90lb @ 1.8" closed, 294lb @ 1.25" open.

stock 3400 cam lift is .2727" int/exh, which is .4363" valve lift with 1.6 rockers, and .4636" with 1.7 rockers.

LS1 valve lift is .472"int/.479"exh, and LS6 valve lift is .552"int/.548"exh, both with stock 1.7 rockers. If you subtract the .1" install height difference from either of those lift numbers, they are still greater than the amount of valve lift with a LA1 with 1.7 rockers and stock cam, so either spring should have enough compression to work.

geoffinbc
04-14-2005, 12:13 AM
The cam you get will have recommendations for seat and open pressure. Pick the spring that will work best.

Froggx
04-14-2005, 02:34 AM
The cam you get will have recommendations for seat and open pressure. Pick the spring that will work best.

I wish they had shared that with me on my regrind :(

geoffinbc
04-14-2005, 08:34 PM
On a regrind you may want to go slightly stiffer than stock. A regrind isn't going to be amazingly different than a stock cam.

I wouldn't expect a reground cam to come with spring recommendations.

Froggx
04-15-2005, 01:26 AM
On a regrind you may want to go slightly stiffer than stock. A regrind isn't going to be amazingly different than a stock cam.

I wouldn't expect a reground cam to come with spring recommendations.

You're right, I keep forgetting the Gen 1 and 2 motors have aftermarket cams :slap:

GinoBeats
04-15-2005, 11:45 AM
My 25759-12 set should be in any day now, checked again and it comes with the M10-3/8 studs so i'll be ok. I'm going to drill and tap the heads for the M10's anyways

geoffinbc
04-15-2005, 12:17 PM
Yes they come with studs. You might consider buying the ARP 8mm to 3/8" studs to save the hastle of drilling and tapping. If you don't drill and tap absoutley perfect you will fuck up the heads. Unless you are experienced in doing the process I would avoid it.

I hope you have a giude block for the tap :P

GinoBeats
04-15-2005, 12:47 PM
Its no problem at all :wink:

91BerettaGT
05-28-2005, 11:25 PM
Sorry to bring an old thread alive again...

I was just thinking, There's mentioning of requirement of Guideplates for using the 1.6:1 Ratio Gold race rockers (the ones you need to clearence the upper lower intake gasket for)

My Intake Manifold has guide plates, do i cut off the gasket's guide plates and use my 2.8 Guide plates? Or just scrap the 2.8 guide plates and use the Intake manifold's guide plates.?

In that picture on the first page, is that the only required clearancing spots?

geoffinbc
05-29-2005, 03:51 PM
You must cut the gasket guides off. They are not sufficient for guiding the pushrod. They are only there to hold the pushrod during maintainence. Cut the guides and install your 2.8L metal pushrod guideplates.

GinoBeats
05-29-2005, 03:56 PM
Yeah i've got the Gen II guideplates only because I have lots of heads lying around otherwise I would of ordered the early Gen II guides. But yeah everything seems to be ok, i've got '04 heads being an '04 engine so I ended ordering up the M8-3/8" studs from Comp. As well as their LS1 springs, running 25759-12 crane set and the rest is chromoly, I'll have to post up some pictures soon

AaronGTR
05-29-2005, 08:20 PM
The things on the intake manifold gaskets aren't guide plates. They are just there to hold the pushrods during installation, and maybe to make the gasket stronger. You need the metal ones that actually bolt to the head under the rocker studs. Gen2 or early gen3 heads had them. You will need to cut or sand down the back side of the gasket where it comes close to the new guide plates so the gasket will sit flat. I just sanded them with a dremel and got enough clearance.

GinoBeats
06-16-2005, 10:01 PM
Just finishing up checking and adjusting the valvetrain geometry I didn't want to start another post but basically a few situations here as my crane 25759-12 rocker arm set does touch the valve cover. Would you say, take a small amount of material off the rocker arms to prevent the contact, or create spacer plates for the valve covers to increase the height, or somehow modify the depth of the baffle inside the valve cover, i.e, machine some material down so that the battle sits down 'further'. Other than this there are no other issues. Oh yeah the bolt holes in the guide plates are larger for those like myself running with '03 and up engines with the M8 studs hehe

GinoBeats
06-17-2005, 01:55 PM
Actually we have worked away around it, I'll post pictures up next week :twisted:

EspanolaGuitarista
06-17-2005, 05:58 PM
Double up on the valve cover gaskets, with some gasket sealer. They won't leak, gino. It shouldn't be a big deal.