bl85c

iTrader: (2)

Actually I just wanted a really long title. So you want a 3x00 roller valvetrain? Feel the need to spin that 'lil v6 till the bearings say uncle? You say 7,000rpm just isn't enough and you want it spinning so fast you smear piston all over the bores? Well this won't get you there but it will certainly add at least another 1,000rpm to your powerband before valvefloat sets in. I think this retrofit has been a long time coming for these motors given what the bottom end is rated for and how soon the stock valvetrain craps out. Now you need to know that this isn't a bolt together deal and requires fabrication, but it's worth every bit of powerband you'll get out of it if you really want to make these motors shine.

Before we get into the details take a look over this thread if you plan on doing a hybrid build. Some will call me crazy or overreacting for suggesting it, but I genuinely believe that your valvetrain will have a longer life with equalized tappet face oiling if for no other reason than the cooling the redirected oil will have.

The main problem is mounting 3x00 antirotation bars to the rwd block. They won't sit flat on the block because of the webbing so you will need to trim with a die grinder or dremel untill they're flush. How much you trim and where will vary with each block so I haven't included pics. Put your lifters in the block and the antirotation bars over them to make sure you trim exactly where needed. Trimming takes some time so be patient. I ended up cutting most of the tubes where the bolts go off so you can probably just trim them off to make things go quicker.

Now that they're flush with the block you can pop some marks on the block using a center punch through the bolt holes on the antirotation bars so you know where to weld studs. If you don't want to weld studs to the block you can also fabricate some hold down bars that bolt to the lower intake manifold bolt holes on the heads like this guy did (post #4). Before welding you need to heat the block with a torch to get adequate penetration and ensure that the studs don't come loose. Obviously plug anything you don't want welding spatter on/in. Clay used for ceramics works well for plugging holes and washes clean. Make sure you have a clean surface to weld on, most blocks were powdercoated from the factory. Lay nice thick welds at high voltage. It won't be perfect or pretty because you're welding on cast iron and penetration will still suck, but a nickel sized blob around each stud is good enough that the studs can't come off. Compression nuts and/or loctite to keep the nuts from vibrating loose is a good idea, and spring washers will keep proper tension on the bars without overtightening and warping them. Look, lifters that don't rotate! Your shiny new cam is safe.

Now you can focus on the second issue, cam thrust. This is more straightforeward but still requires some fabricating. There's 2 ways of doing this so pick your poison.

1) Drill & tap the cam for a 3 bolt cam sprocket. You need to chamfer the sprocket pin hole and hone out the sprocket locator hole a bit to make it fit the roller cam first. Place the sprocket on the cam then pop the cam with a center punch in each of the bolt holes and drill & tap for the bolts. It just so happens that a cam button for a sbc will fit perfectly into the end of the cam sprocket locator hole. Grind the cam nose down to .2" and place the cam button large side against the cam nose so you can bolt the button to the cam between the sprocket & cam. You want to grind the large end of the button down to .130" thick and the small end down until the total button thickness is .575" so you can place shims between the button and cam nose. A nylon drainplug washer works well as a shim and to tighten the button down without effecting cam sprocket torq. Then assemble the sprocket/button combo and place in the block. Put the timing cover with gasket on and adjust the shims until you can place the cover on flat. Measure your actual thrust with the timing cover on using the cover on the backside of the block and adjust until you have .08" thrust. See the attached pics for a better idea of how the button is assembled.

2) The far easier but potentially less reliable method is to simply use the stock roller cam bolt and weld a nub on the end to establish proper thrust. Permanent loctite is NECCECARY because the cam bolt has the potential to work it's way loose. When the nub contacts the timing cover it will put counterclockwise force on the bolt causing the bolt to loosen. The bolt won't have anywhere to go but eventually the pin will shear off causing major havoc, which is why I chose the first method.

Either method requires a .140" thick spacer that goes between the cam and sprocket to use a 3 bolt sprocket. The roller cam sprocket will give the correct depth but won't line up with the crank sprocket and can't be used. Cutting the center section out of a stock cam sprocket works well as a spacer when ground to the proper thickness. I chose to make a steel spacer out of a large washer so I was certain it wouldn't crack once torqued, a pic of my spacer is attached.

Now you need to figure out what pushrods you need. If you're doing a hybrid build this is simple, the factory roller pushrods work fine. Iron heads require you measure pushrod length using an adjustable pushrod length checker and either find oem pushrods with the correct length or having custom pushrods made. I have heard that the intake pushrods for roller 3x00's are the correct length but have not verified this. After all is said and done you will be limited to about .350" lobe lift (.56" valve lift with 1.6 rockers) with most blocks to keep the oil chamfer .02" in the lifter bore and prevent pressure loss. I only have .319" lobe lift on the exhaust side for .51" lift and I have no problems.

3x00 roller rockers can be retrofit onto iron heads using 3/8" studs and polylocks or another good locking nut. To remove the rockers from the pedestal you simply unscrew the bolt from the pedestal. It will take some force to get it started and continue to loosen it but keep working at it. Then just slip it onto the stud and adjust lifter preload as you normally would. Aftermarket aluminum rockers are available as well but I preffer oem parts when possible. They're designed with the greatest longevity in mind at the lowest cost. To compliment your roller valvetrain 3x00 beehive-style valvesprings are a superior choice to the conventinal springs found on iron heads. Even better are LS6 'yellow' valvesprings or other beehive springs made by comp. These alone will have a tremenous effect on how high you can rev your motor without running into valvefloat. Gains of 500rpm are typical with these springs alone. Spring keepers and locks can be had off any roller 3x00 at your local pick-a-part, and the correct valvestem seals and spring seats if using aluminum heads can be had at wot-tech.com. As always double check all your dimensions, clearances and torqing proceedures before assembly.

Contrary to what some have claimed there are no oiling problems with this conversion. There is no hole underneath the roller for oil to 'puke' and starve the rest of the oiling system. The chamfers on the 3x00 lifters are in the correct position and oil can freely flow throughout the oiling system at all times, and the same volume of oil is pumped to the rockers as would be with flat tappets so there's no danger of sucking the pan dry. I and others who have done the conversion haven't had any problems. My 1-2 shift is at 7,000rpm, 2-3 at 6,500rpm and I have spun it up to 8,000rpm with no drama.
Well, there is some.

project89

iTrader: (1)

while u wont get the benifits of the roller lifters there is a simpler way to get more rpm out of the hyd flat lifter 8k-8500 is possible with the proper valve springs
this involves taking apart ur hydralic lifter and shimming underneath the plunger with "an" washers and a small stiff spring.its essentially turns ur hyd lifter into a solid lifter but not fully, this mod allows enough travel in the plunger that u dont have to adjust the valves every 3k miles and u dont have a super noisy valve tian
.

if u guys want more info ill post up some more detialed info and if i can some pics on how to do the mod. i think the cost is roughfly about 30 bucks + valve srpings and is the sae mod i run in my own engine

bl85c

iTrader: (2)

Anyone can add whatever they have to contribute as long as it's relevant. I might even try your mod out on a motor I'm building for an s10.

bl85c

iTrader: (2)

Updated measurements and pics.

project89

iTrader: (1)

blc u still have any of the stock hyd flat lifters laying around i dont have a camera to take pics to exoplian my mod maybe u can dismantle one and take some pics o post ?

bl85c

iTrader: (2)

I will once I put the roller cam back in. Got it back from delta with the correct duration finally. Can't wait to take it to the track once I get my 3500 plenum from firstfirebird!

bl85c

iTrader: (2)

Ok, continue.

project89

iTrader: (1)

thanks man one more thing can u get a measurement of travel in the plunger for me i dont have my numbers off hand and i need that number to come up with the shim thickness

bl85c

iTrader: (2)

About .490" assembled.

project89

iTrader: (1)

hmm i dont rember the plunger having that far of travel ima have to see if i can dig up my old numbers and dbl check that

bl85c

iTrader: (2)

Err, .215". Forgot to subtract plunger depth duh.

project89

iTrader: (1)

much better i was thinking .240 myself
im going to get some part numbers for some washers before i post up the directions this way anyone who does it can get the exact thickness washers and not screw up the mod

DeathStarr89

iTrader: (1)

Or you could just use a gen3 block and avoid all the drama. Much easier to modify the V6 clamshell mounts, notch the K member and the flexplate dust cover. you get a stronger block, better oiling and other improvements.

project89

iTrader: (1)

grrr i had photos edited to show were to install the washers and how to modify the spring,and had the whole hing written in notepad so i could copy and paste it into a post but i deleted it by accident grrrrrr


ill redo it and post it up later tongiht

bl85c

iTrader: (2)

Believe it or not there's people that don't want to swap blocks. Some want to keep the original block, some are just stubborn I guess. I on the otherhand finished assembling this thing quite a while ago and wasn't about to take it apart again.

project89

iTrader: (1)

alright this is my second time typing this up i accidently deleted the notepad file i typed it into so when i could get online i could copy and paste it into a post

anyways here we go

blc has the image of the stock lifter posted along with the plunger travel,what this mod does is stop the lifter from collapsing when i high presure valve spring is used. its not actually the mod that stops the valve float, the mod gives u the ability to run a much stiffer valve spring, and this is what gives u the extended rpm cababilitys.

basically what this involves is getting some "an" washers that fit inside the lifter body, this inturn removes the travel from the plunger but still leaves enough that the lifter can basically keep the lash right as parts start to wear.

before this mod the plunger has about .220 travel so say ur cam has .440 lift ( i dbled the plunger travel number to make this easier to explian) now say u install a stiffer spring but it causes the lifter to collapse, whats happening is the plunger is droping into the body and u lose lift at the valve( if it collapses fully u would only see .220 lift at the valve. I.e actual lift minus how much the plunger drops into the body), not to mention u start to bounce the lifter off the cam which is not good.

so to get past this we shim under the plunger to take up the amount the plunger can drop in
idealy u want to shim it so that there is only .030-.040 travel in the plunger.now when u set the valves the plunger gets sunk down .015 to .020 thousands, this is what gives the hydlifter the ability to keep lash setting, unlike a solid lifter which as everything wears u need to remove the valve covers and reset the lash by adjusting the nut on the rocker arm, or on some rockers there is an adjuster that sits above were the pushrod is.

now witht he spring if u just try to reinstall the spring it will be to long and the lifter will not go back together.

!!! DO NOT REASEMBLE THE LIFTER WITHOUT THE SPRING !!!

what u have to do is either cut the spring down so it fits in there and still has a lil bit of trouble before the spring binds or get a new spring that fits in there and dosent bind

if u dont use a spring u will have a very hard time setting valve lash and will have a very noisy valve train during startup till the lifters pump back up with oil

ok now that ive explained that lets move on

so now u have a lifter with only .040 travel and the plunger is already sunk .020 that leaves .020 more travel in the lifter body, so if the lifter collapses u only loose .020 lift. but since the lifter is now firmly bottomed out and the valve spring is stiffer it can keep the lifter against the cam lobe .

see attached picture for were to put the washers in the lifter


any ?'s just ask


i do recomend u do the oil pump mod along with this, this is basically u take the bottom cover off the pump and knock the roll pin out of were the oil presure relief valve is, carefully pull out the valve and the spring, shim the spring with 2 "an" washers and resinstall, this will raise oil presure 15-20 psi, ( be aware that if this raises oil presure above ur stoc gauges capacity when the oil presure climbs ur gauge will drop instead of just pegging itself so dont be alarmed if that happens this is the reason i have an oil presure gauge in my car that reads 0-150 psi as i have mine shimed with 3 or 4 washers and have 60+ psi at idle and over 110 psi at redline) before i put in the aftermarket gauge the gauge would peg then drp to 0 right off idle

DO NOT SHIM ANYMORE THEN THIS (1 or 2 washers)
unless u are building a motor and u have extra clearance in the rod and main bearings, to much oil presure with stock clearances is not a good thing

i found out about this mod from my uncle who was helping me with a valve float issue when i first assembled my motor, i was floating the valves with the 260 cam with valve srings rated at 105# seat and 235# open i believe, after he showed and did this mod for me i steped up the springs and got another 1,200 or so rpm out of it, the springs i went with are from kmotion and have 125 or 135# seat presure and over 325#'s open normally these would collapse a hydralic lifter but i have yet to have any issues even with the more aggressive cam



btw this mod should also work on a hyd roller lifter but i havent had one apart to see or try it

DeathStarr89

iTrader: (1)

I noticed that about Fbody V6 guys and even some Fiero guys, i think once you see the results from the FWD block swaps those stubborn people will change their minds.

Also, keep in mind your rods are only rated for 7K RPM from the factory, many years of use and you can be pretty sure that those rod bolts aren't in tip top shape anymore. If you have enough port flow and cam to get to make useable power up that high then it would be a good idea to get the crank checked, rods reconditioned and throw in all new bearings.

bl85c

iTrader: (2)

All the expendibles are brand new and everything's balanced/checked. I set out to build a motor not bolt a bunch of crap together and hope it worked lol.