cam break-in procedure

grumpyvette

Administrator
Staff member
Cam Break-in Procedure

• Have a high quality service manual available, such as the factory service manual, or the vehicle specific manuals published by Chiltons, Motors, or Haynes. You will need these for the basic information regarding engine disassemble and reassemble along with the torque settings for the various fasteners.

• Read and understand the manual completely, along with these instructions before you begin working. We highly recommend you also have the assistance of a knowledgeable friend to assist you, especially during the initial fire-up and break-in period.

In addition to the normal installation procedure, installing a performance camshaft requires you to check for several extra items to insure long life and optimum performance.

• New Lifters Are A Must- There is no such thing as a good used lifter! Any flat faced lifter establishes a wear pattern almost immediately with the cam lobe it is riding on and cannot be used on any other cam lobe, let alone a different cam. Should you have a need to disassemble the engine, make sure you keep the lifters in order so they go back on to the exact same lobes.

• Valve Spring Pressure and Travel- We highly recommend purchasing the matching valve springs recommended in our catalog. This insures you will have the proper pressures, both closed and open, and sufficient travel to get the maximum rpm, performance and life from your new cam.

• Piston to Valve Clearance- While many performance cams will work just fine with stock pistons, there are many factors that effect your engine and the clearance available. Things such as factory tolerances, normal machine work such as head and block surfacing, aftermarket components such as cylinder heads, higher ratio rocker arms, etc. all effect your engines ability to handle a performance camshaft.

• Valve Train Interference- In addition to valve spring travel and piston-to-valve clearance, a commonly overlooked area is that of retainer to seal clearance. The other common area of interference is rocker arm to stud clearance along with rocker arm travel. The best way to check these is by physically opening both a intake and an exhaust valve on each cylinder head to the gross lift of the cam plus and additional .030". It is easiest to do this by pressing down on the rocker arm with one of the many tools available. Do not simply rotate the engine to the maximum lift point for a given valve. This does not work when engines are hydraulic lifter equipped, or even allow any margin of safety when you are using a mechanical lifter cam.

• Valve Adjustment- The easiest way to insure proper adjustment is to adjust the rocker arms as you install them, one cylinder at a time. Adjust the intake valve as the exhaust valve is just starting to open and adjust the exhaust valve when the intake valve is almost closed. It is simplest to do this with the intake manifold off and watching the lifter’s movement.

• Hydraulic Lifter Valve Adjustment- All engines, regardless of manufacture, require correct valve adjustment. Some engines, such as Chevrolet V-8’s, are equipped with stud mounted rocker arms can easily be adjusted to compensate for changes incurred during engine assembly. Never just torque the rocker arm into place and assume that the lifter preload will automatically be correct. Various engine manufacturers use multiple length pushrods, shims, and spacers to compensate for changes in preload. Hydraulic lifters cannot compensate for all changes. Ideal lifter preload is .020" to .080". Do not attempt to fill the lifters full of oil prior to installation. They will fill automatically once started and manually filling them makes adjusting the preload a difficult task.

• Mechanical Lifter Valve Adjustment- Adjusting mechanical lifters should be done the same way as outlined above, one valve at a time. For an initial setting, we recommend .003" to .005" than listed on the cam’s specification card. Once broken in and with the engine fully warmed up, re set the rocker arms to the cam’s specification sheet.

• Installation Lubricants- All flat faced (non-roller) camshafts require the use of high pressure lubricant supplied with your Erson cam on the bottom of the lifters, the lobes of the cam and on the distributor drive gear. Do not use this lube on the tips of the pushrods, the sides of the lifters or on the rocker arms. Use a quality oil when installing roller tappets.

BEFORE YOU TURN THE KEY

• Fill All of the Engine’s Fluids- Using a minimum of a SAE API SD, SE or better fresh clean mineral based oil, fill the engine to the proper level. Do not use synthetic oil during break-in. Fill the coolant system and follow the instructions on purging air from the system. With carburetor equipped engines, fill the carburetor to insure fuel is available immediately. Make sure that the ignition timing is properly set to insure immediate starting, without excess cranking of the engine.

• Pre-Lube the Engine- Using a oil pump priming tool such as those available from Mallory, spin the engine’s oil pump until you see pressure on the gauge or have oil at the rocker arms. Do not attempt to prime the engine using the starter motor!

• Proper Ventilation- Make sure that you do not start the engine without good airflow. That means have the overhead garage door open and the exhaust vented to the outside. If you have any doubts about sufficient airflow to the engine, push the car out of the garage to make sure the radiator can draw in plenty of air. Having a fan to blow fresh air through the garage is a plus.

• Exhaust System- If at all possible, start the car with a muffled exhaust system hooked up and operational. It makes it much easier to hear what is going on.

• Resist the Urge- Take a minute before you try to start the engine for the first time and double check that you are ready to go. Don’t take any short cuts or leave parts such as fan shrouds, air cleaner, wire looms, etc. off. Clean up the are around and especially under your vehicle. Pick up your tools and wipe up the floor so you can easily spot even a minor leak.

• Be Prepared- Have extra coolant or a hose handy, clean rags, tools for tightening clamps, connections, etc. just in case. They need to be in place to make sure you have an uneventful break-in of the camshaft.

WHEN THE ENGINE STARTS

• Have a Helper- Now is the time for a helper. They can check the coolant level, check for oil and fluid leaks, and proper operation of underhood accessories. Air pockets in the coolant system are common so make sure the recovery bottle is checked and filled as necessary. You cannot count on the temperature gauge. Temperature gauges are only accurate if the sensor is submerged in coolant and will not give an accurate reading if in an air pocket.


• Do Not Idle the Engine- As soon as the engine starts, raise the rpm to 2,000 rpm. You should also constantly vary the RPM between 2,000 and 3,000 RPM for the first 20 minutes. This is the only way to insure proper lubrication during this critical period since the camshaft to lifter contact area relies almost exclusively on oil splash from the crank and connecting rods. Make sure that you run the engine for a full 20 minutes using this procedure. It will seem like forever, but it is one of the most important steps to insure long, dependable performance.
Ive always smiled when I saw that same instruction, thinking, now how in hell are you going to set the timing at idle when your not allowed to let the engine idle during the cam break-in process, years ago thinking the same question,the answers simple but it takes experience before you realize the answer, you simply set the timing with a TIMING TAPE on the damper at about 32-36 degrees at 3000rpm, and watch the temperature on the exhaust with an INFRARED temp gun,as a guide in almost all or at least most cases, if the exhaust gets cherry red quickly its usually an indicator your ignition timing is retarded or the fuel/air mix is lean,that will be very close to correct when you drop the rpms to 1000 once the cams broken in, after 30 minutes, obviously you need to find TDC during the cam installation and degreeing in process an install a timing tape or use a pre-marked damper, so you can accurately set the timing at 3000rpm

Once Break-in is Complete- Drain and replace the engine oil and filter with new, fresh oil and a new filter. Recheck for any fluid leaks and check all fluid levels. If you installed a mechanical lifter style camshaft, flat faced or roller style, the valve adjustment should be rechecked at this time with the engine fully warmed up. Hydraulic lifter equipped engines should not require any readjustment.

Proper maintenance is important for any vehicle. Frequent oil changes, with a new filter is one of the easiest ways to insure your vehicle will deliver the performance you want for many long happy miles.


ID ADD, USE a GOOD MOLY BASE ASSEMBLY LUBE AND A HIGH ZINC CONTENT OIL AND SOME G.M. E.O.S. TO THE OIL

MARVEL MYSTERY OIL is a good high detergent oil designed to aid valve train and rings ETC. cleaning, I almost always add about 10% marvel mystery oil to my engines, but if your running flat tappet lifters Id point out that many current oils are designed for roller lifter engines so Id select an oil that's designed for the older design with the higher zinc content, and adding a can of E.O.S. to the oil and moly assembly lube on the lifters and cam, sure won,t hurt on that first break in, if your breaking in the engine in your driveway, have a running hose and a fan handy, water running thru the radiators cooling fins and a fan blowing air helps prevent over heating, have a timing light and USE IT, check your fluid levels and watch your gauges

Now it should be obvious that reducing the pressure at the contact point between the lifter and the cam lobe will tend to reduce the tendency for lifter & lobe wear, and increasing the coolant flow at that point helps, so its generally a good idea to remove the INNER spring on DUAL spring valve trains during the break -in process, to reduce pressures while the parts lap in, and a few minutes with some 1000grit sand paper to remove burrs from the lifter edge sure helps in most cases

GM’S RECOMMENDED CRATE ENGINE START-UP PROCEDURE
Print this page out and check off boxes below (in the printed copy) when each step is completed.
Step Box
1) Safety first! If the car is on the ground, be sure the emergency brake is set, the wheels are chocked, and the transmission cannot fall into gear. Next verify that all hoses are tight and that both the radiator and radiator over flow jar/tank are full and have been filled with the proper anti-freeze and water mix.
2) Before starting your engine for the first time, add one pint of engine oil supplement ( EOS¹) to the crankcase oil and then check the oil level. Once this has been done, prime the oil system with an oil pump primer tool. Make sure number 1 cylinder is on TDC compression stroke, and install the distributor.
3) Adjust the distributor timing roughly by hand for a quick start up and smoothest idle possible.
4) When the engine first starts, verify that the engine rpm is at a safe level and that the timing is set near or at 30° before top dead center (BTDC). Run the engine speed between 1,500 and 2,500 RPM’s, varying the engine speed up and down with-in this range, to prevent overheating of the exhaust valves and the exhaust system. This should be done with no-load on the engine and for the first 30 minutes of operation.
5) After the first 30 minutes of the engine running, set the ignition timing according to the timing specifications. Now would be a good time to check thoroughly for leaks.
6) Adjust the carburetor settings, if necessary.
7) Drive the vehicle with varying speeds and loads on the engine for the first 30 miles. Be sure not to use a lot of throttle or high RPM.
8) Run five or six medium-throttle accelerations to about 3,800 RPM (55 to 60 MPH), then letting off in gear and coasting back down to 20 MPH.
9) Run a couple hard-throttle accelerations up to about 3,800 RPM (55 to 60 MPH), then letting off in gear and coasting back down to 20 MPH.
10) Change the oil and filter with recommended oil (10w30SG in most cases) and filter.
11) Drive the next 500 miles normally, without high RPM’s (below 3,800 RPM), hard use, or extended periods of high loading.
12) Change oil and filter again.
13) Your engine is now ready for many happy cruising miles!
Note¹: EOS P/N 1052367 can be used any time during the life of the engine.
Technical Note: This procedure has been corrected and improved from the original GMPP procedure by GILBERT CHEVROLET.


sitting with no air other than the fan moving air thru the radiator is bound to run a bit hotter than on the road, anything under 220F is normal /expected under those conditions.
I run a water hose thru the radiators cooling fins when testing under those conditions., on the street it should run fairly consistently in the 180F-190F range with a 180F T-stat.
in many cases an ADDITIONAL TAURUS electric fan from a salvage yard can be installed on the other side of the radiator to run off a dash switch or sensor that will provide additional cooling when needed.(price varies but its usually very reasonable from salvage yards)

DROPPING THE DISTRIBUTOR BACK IN
viewtopic.php?f=50&t=54


http://forums.hybridz.org/attachment...3&d=1218835261

or

taurus-fan-power.jpg


190F-210F is ABOUT NORMAL,for driving temps, and nothing to worry about, adding a seperately mounted TRANSMISSION COOLER if you have an auto trans is usually worth a 10-15 degree drop in the coolant temp,MINIMUM, if the current trans fluids cooled in the lower radiator, adding an 8 qt baffled oil pan is usually good for an additional 7F-10F degrees reduction in oil temp alone
A great deal of the heat is transfered to the oil and trans fluids long before the radiator and coolant sees it,routing the hot trans fluid to an aux cooler and adding a high capacity oil pan significantly reduces the heat the radiator needs to transfer from the coolant to the air flow thru it.
http://store.summitracing.com/partde...5&autoview=sku
 
tim said:
grumpy am I understanding this correctly, any Flat tappet requires the 30 min break in process, correct?
Hydraulic roller cam and lifters require no break in process, as in put oil in the engine and go start it up when its assembled?
It is when they stop spinning that the camshaft and lifters fail and become a lathe.

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its true that roller cams and lifters do not generally require the same 30 minute 2500rpm-3000rpm break-in period that a flat tappet lifter requires to allow the lifters and cam lobes to lap in, but be aware that most roller cams and lifters are packed with a rust inhibiting packing grease so careful cleaning of the cam followed by a coating of assembly lube is the preferred way to install a roller cam, I generally soak new roller lifters in a can of marvel mystery oil for at least a few minutes and preferably for at least an hour prior to assembly and manually turn the engine and prime it until I see oil bleed, freely from ALL the rockers before starting any engine. and remember its mandatory you verify ALL VALVE TRAIN clearances and valve train geometry prior to starting any engine

IT should be obvious that you'll need to pre-prime the blocks oil passages and adjust the rockers so oil flows from the rockers with the engine being pre-primed with a priming tool being used BEFORE trying to start any engine with a new cam to insure oil flow begins instantly on the engines start-up,you WON,T get oil to all lifters equally unless the engines crank & cam are spinning,(so during testing spin the engine slowly with a breaker bar or ratchet), because the oil passages feeding the lifters aligns differently at different lifts,your oil leak at the distributor base is normal, but the clearances and flow may be excessive, with a priming tool, some are not nearly to spec. ID measure the diam. of the oil pump primer and then measure the distributor base, Id bet the distributor base is larger and fits better, which reduces the potential for leakage.
SBCprimer.jpg

Even with roller valve train there is a break in period where the metals have to "mate". on flat tappet valve trains and non-roller rocker valve trains use of a good moly assembly lube is critical, Break in oils and assembly lubes have high pressure additives to help protect these new surfaces while this "mating" is taking place. Regular motor oil does not, always have the required additives or enough of them. thus using a good moly based assembly lube on lifters and bearings helps reduce wear , on roller rockers and roller lifter a mix of 50% assembly lube and 50% MARVEL MYSTERY OIL, thins this moly mix viscosity allowing it to penetrate roller bearings far faster

crcassembly.jpg

marvel.jpg

those bottom two bands form a wall on the oil passage, some guys cut a rounded grove and install an O-RING so the upper band seals too the block, you don,t want to do that to the lower band simply because that's the oil flow source to the distributor /cam gear
20 psi is about normal for your typical 3/8 drill,max pressure is not nearly as important as checking flow, and for leaks where there should not be leaks, with an engine primer tool,Ive brazed a socket to the top of my oil pump primer and use the 1/2" drive air ratchet to drive it, it won,t heat up and burn up like a electric drill will.
don,t get alarmed if you get zero pressure or flow for a few seconds,(the oil filter and passages need to fill first) that's one reason WHY your pre-priming, to get oil flow to the bearings instantly on start up , you don,t want them running without oil flow if you can prevent it even for 20 seconds
 
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crower cams and howard cams sell lifters with holes machined in the lifter face,

http://www.competitionproducts.com/prod ... r=651080DL

651080DL.gif

theres a small hole machined into the base of the lifter face that directs a constant stream of pressurized oil into the lobe/lifter contact area, thus theres never a lack of lubricant like could occur at low rpms with standard splash lubrication,(the main reason they tell you to break in cams at 2500rpm-3000rpm)
this works great on solid lifters but they can,t do that with hydraulics because the oil is used to float the push rod seat and take up lash, solids run lash clearance so they can use that method of extra lube

http://store.summitracing.com/partdetai ... toview=sku

comp cams sells a lifter bore groove tool

cca-5003_w.jpg


that allows you to groove the lower 1/2 of the lifter bore so the lifter oil passage sprays oil onto the cam under pressure

there ARE lifters in both hydraulic and solid lifter designs that have a very small flat ground on the lower outer 1/2 of the diam. that allows extra oil to spray as the lifter rotates in its bore, and an old hot rodder trick is to do the same thing with 600 grit sand paper laid on a sheet of glass and with a few passes you can do the same basic thing on standard lifters if your very careful

its been my experience that many cam failures are related to clearance issues or lack of correct lubrication far more than the use of the less than ideal spring load rates.
you might be amazed at the number of guys I see who install valve springs, even shim them to the correct height but never check the retainer to guide clearance,valve seals or valve train geometry, or bother to verify the oil flow thru the valve train, on all 16 rockers
and adding a few of the correct magnets traps almost all the metallic crud from worn lifters and lobes BEFORE it gets into the oil pump
viewtopic.php?f=52&t=282

viewtopic.php?f=52&t=181

notice the approximate location and relationship between the cam pin and crank key

http://www.superchevy.com/technical/eng ... index.html
sucp_0609_06_z+chevy_small_block+timing_gear_and_chain.jpg
 
BTW if you go to change the valve springs with the heads still on the engine, or TEMPORARILY remove the INNER springs while you break in a CAM, most guys use the hose they use to do a compression check and the spark plug adapter and pump the cylinder up with about 125 psi of air to hold the valves shut while they do it, yeah it usually works just fine.
sun-cp7827_w.jpg

viewtopic.php?f=50&t=404&p=496&hilit=rope+adapter#p496

(yeah theres a different method)
(1)disconnect the battery
(2) remove the spark plugs, and rocker arms
(3)turn the first cylinder to BDC BYE HAND or someplace close to that
(4) insert one end of 5 ft of 3/8" rope into the cylinder thru the spark-plug hole and be sure you tie a KNOT in the other end
(5) rotate BYE HAND,the engine until the rope compresses against the valves holding them in place
(6)REPLACE THE SPRINGS on that cylinder while the valves are held to the combustion chamber roof
(7)rotate the cylinder back to BDC
(8)pull out the rope

(repeat 7 more times)

yeah! the air USUALLY works but I don,t trust it EITHER, I want those valves locked from falling into the cylinder PHYSICALLY:D :thumbsup:

BTW youll want one of these or something similar
sum-906784.jpg

mor-62370.jpg

http://store.summitracing.com/partdetail.asp?part=SUM-906784&autoview=sku

IVE done it both ways many times, Ive never trusted the air alone but Ive used it without problems in the past, the ropes usually not a problem,, and yeah theres the potential for it to tangle but I have not had that happen either
 
youll be best served following the manufacturers suggested clearances or (LASH). if your running a solid lifter cam, if they suggest .016 than set them at that, its not critical that they are EXACTLY .016-018,should be fine, but get it as close as you reasonably can.
generally set them on a warm engine , but be 100% sure the valve train geometry and clearances are correct and oil flows from each individual pushrod to each rocker,
heres a few useful links

http://www.wallaceracing.com/valvelash.htm

http://www.cranecams.com/?show=faq&id=4

http://www.chevyhiperformance.com/techa ... index.html

http://www.centuryperformance.com/adjus ... g-149.html

http://www.small-block-chevy.com/cb_5.htm


when the push rod geometry is correct, this is what the rocker rub marks look like on the valve tip
valvetip.jpg





ok how do i adjust them now?

http://www.thedirtforum.com/chevyvalves.htm

http://www.2quicknovas.com/happyvalves.html



http://www.centuryperformance.com/valveadjustment.asp


http://www.boostandfuel.com/support/setting_valves.htm

http://www.carcraft.com/techarticles/87998/index2.html

http://www.angelfire.com/fl4/pontiacdude428/valveadj.html

btw if your totally new at this the tappet feeler gauge measures the lash clearance between the valve and rocker on solid lifter cams

I just don,t think adjusting the valves without the oil pressure and the block up to operating temp. is the best way to adjust valves , but yes you can do it just fine with several methods described above

how do you adjust valves at idle without the mess of oil getting all over the engine and headers

HIT A FEW YARD SALES, SWAP MEETS UNTIL YOU FIND A DIRT CHEAP SET OF TALL CAST VALVE COVERS LIKE THESE, the CONDITION THEY ARE IN ,WITHIN REASONABLE LIMITS OF COURSE IS NOT THAT IMPORTANT
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you simply cut the ribbed center section out of the valve cover, and glue the synthetic valve cover gaskets on them in the normal location,
when you go to adjust the valves you first remove the standard valve covers and install your VALVE ADJUSTMENT COVERS, they retain about 80%-90% of the oil that would normally be lost over the edge of the cylinder head while adjusting a running engine, they also catch much of the splashed oil, just leave a 1/4"-3/8" of the rolled top for strenth around the perimiter of the top surface. I bought my set for $10, they were old and slightly discolored but I could not care less! I took them home and used a drill and saber saw to remove the center ribbed area, theres several brands that are very similar in appearance, all will work! and Ive used them for over 25 years, if I remember correctly they are mickey thompson brand


now if the lifters are hydraulic of course you just back the adjustment nuts off the rocker studs with a wrench, slowly until the rocker JUST starts clicking , then slowly tighten the nut just up to the point that the clicking stops then add 1/4 to 3/8 turn to preload the lifter and move to the next rocker and repeat, the only difference with solid lifters is you use a feeler gauge inserted between the valve tip and rocker after they click slightly,to measure the lash distance recommended on the cam spec. card (normally .016-.028 thousands) and you tighten them just to the point at idle that the clicking stops... then you remove the feeler gauge and move to the next rocker
if your useing jam nuts dont forget to lock the allen key


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Valve Adjustment: ENGINE OFF!

with #1 cylinder Intake Valve at full valve lift .... Adjust #6 Intake Valve
with #8 cylinder Intake Valve at full valve lift .... Adjust #5 Intake Valve
with #4 cylinder Intake Valve at full valve lift .... Adjust #7 Intake Valve
with #3 cylinder Intake Valve at full valve lift .... Adjust #2 Intake Valve
with #6 cylinder Intake Valve at full valve lift .... Adjust #1 Intake Valve
with #5 cylinder Intake Valve at full valve lift .... Adjust #8 Intake Valve
with #7 cylinder Intake Valve at full valve lift .... Adjust #4 Intake Valve
with #2 cylinder Intake Valve at full valve lift .... Adjust #3 Intake Valve

Exhaust Valve Adjustment: ENGINE OFF!

If you have noticed, this is the same procedure as the intake valves listed above, just that you are now adjusting the exhaust valves the same way.

with #1 cylinder Exhaust Valve at full valve lift .... Adjust #6 Exhaust Valve
with #8 cylinder Exhaust Valve at full valve lift .... Adjust #5 Exhaust Valve
with #4 cylinder Exhaust Valve at full valve lift .... Adjust #7 Exhaust Valve
with #3 cylinder Exhaust Valve at full valve lift .... Adjust #2 Exhaust Valve
with #6 cylinder Exhaust Valve at full valve lift .... Adjust #1 Exhaust Valve
with #5 cylinder Exhaust Valve at full valve lift .... Adjust #8 Exhaust Valve
with #7 cylinder Exhaust Valve at full valve lift .... Adjust #4 Exhaust Valve
with #2 cylinder Exhaust Valve at full valve lift .... Adjust #3 Exhaust Valve

or if your really lazy (you can use this method on hydrolic lifters)install the tall cut valve covers and just turn the engine about 20 degrees or 1/8th turn,(start anywhere )and take the slack out of any loose rockers, repeat for 720 degrees,(twice around) then go back and give each rocker nut one turn OUT(LOOSER) and start the engine,(yeah it will be messy and noisy) and then go back and turn each rocker IN (TIGHTER) untill it just quits clicking plus 1/3rd of a turn past that point

BTW many chevy rocker studs use a thread pitch of about .040 thousands per turn so once your very familiar with your solid lifter engines needs and the cam lash clearance you need and once you verify the pitch rate of the threads you can adjust solids surprisingly close to correctly by running them in till they quit clicking, then OUT about 1/3-1/2 a turn to get the correct lash rather than IN like on a hydraulic lifter to add preload,naturally you'll need to verify with a feeler gauge.

NATURALLY you need to know the threads per inch on the rocker studs and a quick check with your calculator will give you the necessary info on the clearance a full turn of the adjustment nut advances or loosens the rocker, and be aware that this is not exact but a fast way to get close at the track
DSC01822_800_x_600_.jpg
 
the LASH/PRELOAD on a lifter determines several things and one of those is the voluum of oil forced up the pushrod and the valves abilty to bleed off heat to the heads thru the seat contact.
minimizing the preload allows slightly longer seat contact and greater oil flow to the valve train and less likely hood of burnt valves.
the oil trapped under the pushrod seat in the lifter supports the pushrod and can,t be compressed easily , the total distance for preload adjustment most lifter seats have available is in the .060 range, if you minimize the preload the oil reaching the valve train as the seat collapses and forces it up the pushrods increased, as the lobe spins under the lifter, total valve lift may be very slightly effected , but Ive always prefered durrability over trying for the last possiable bit of peak power.
keep in mind , that clearance is set on a relatively cool engine, once you start running it hard the temp. increases rapidly and that lifter and valve train expand due to heat, minimal valve train clearances, and limited oil flow to cool the springs might become a problem, especially when you realise that about 40% of the engine heat comes not from combustion but from the valve train and springs, and friction, valve springs glow red hot and fail in under 5 minutes at 6000rpm with no oil flow to cool them according to SMOKEY YUNICKS TESTING.
you also must keep in mind that as the rpms increase the TIME available for the lifter to bleed off oil under the lifter seat decreases rapidly, resulting in slightly higher effective lift at the valve.
you might want to keep in mind valve preloads usually set while the engines not nearly as hot and the expansion, of the components due too heat is minimal compared to the conditions durring a race, where extra clearances may be necessary in the valve train once everything reaches true opperational heat levels.

http://www.type2.com/library/engineg/hydral2.htm

http://www.ratwell.com/technical/HydraulicLifters.html
15-Exploded.jpg



BTW EVER WONDER WHY WHEN YOU PRELOAD THE LIFTER MORE THAN ABOUT A 1/4 TURN ON THE ROCKER ADJUSTMENT NUT THE VOLUME OF OIL SQUIRTING OUT OF THE PUSH RODS DROPS OFF RAPIDLY,

thats really simple, the seat in a hydraulic lifter rides on a cushion of pressurized oil, oil that's displaced up the push-rods as the cam lobe sweeps under the lifter base, as the lifter returns to the cam lobes base circle the lifters seat is pushed back up to full height by oil pressure (one reason lifters tend to click with low oil pressure)
the potential problem is that the total distance the seat supporting the pushrod moves is usually about .055 thousands, a full turn on a rocker nut is usually .040, so the more you preload the lifter the lower the volume of oil under the lifter seat

picture may help

BTW roller lifters are very similar just with a roller wheel added to the base
 
HOW TO DEGREE IN A CAM

youll need a few basic tools and a good understanding of what your doing, but its certainly not all that difficult.

I was asked where to get a CHEAP degree wheel

heres one you can print out and save for engine builds on the engine stand
(put curser on an click)

http://www.tavia.com/free_degree_wheel.html

http://store.summitracing.com/partdetail.asp?autofilter=1&part=MOR-62191&N=700+303547+115&autoview=sku

BTW you CAN advance or retard the roller timing chain its done bye drilling out the cam index pin hole in the timing gear and installing an off set bushing

http://store.summitracing.com/partdetail.asp?part=CCA-4760&autoview=sku

cca-4760.jpg




you could buy these from summit racing or similar parts from jegs
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marks_lined_up.jpg
this is 180 degrees out (the distrib rotor points at cylinder #6, so before you drop in the distrib rotate the crank 360 degrees bring both marks to the 12 o-clock location, then drop in the distrib pointing to cylinder #1, and adjust ignition timing from that point

http://www.summitracing.com/

http://www.jegs.com sells this KIT
Comp Cams #249-4796
http://www.jegs.com/i/Comp Cams/249/4796/10002/-1

and you can buy these

MOR-62191 $44 (wheel)

MOR-61755 $47 (SBC)
MOR-61756 $47.(BBC)crank sockets

SUM-900188 $17 (piston stop, head off)
SUM-900189 $6.95(piston stop, head on)

TFS-90000 $94.95 (degree kit)

youll also want two flat tappet solid lifters and two weak check springs

pro-66838_w.jpg

http://store.summitracing.com/partdetail.asp?autofilter=1&part=PRO-66838&N=700+115&autoview=sku
instructions

http://www.iskycams.com/camshaft.html

http://www.thedirtforum.com/degree.htm

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