Hey guys/UDHarold, I have a set of TRW L2465 (0.030) 454 pistons in a balance short block took in as a trade.

I am planning to stick a set of heads on it, and run it.

I want a decent size cam to replace the Comp Magnum 286H that is currently in it.

I started thinking about something. What is the max lift that these pistons can handle? These pistons have a 25.7cc dome that will give me around 10:1 CR with open chamber 119cc heads, 0.039" head gasket and a zero decked block.

Perfect for my street 454 going into my 2800lbs 280z, and still great if I wanna hit it with a 125-150HP of nitrous down the road.

I had planned on using this UltraDyne solid flat tappet grind because I have used it before (with different pistons):

288/296 F10: .612/.630" lift, 288/296 adv, 255/263 dur@0.50", 110 LSA

Does anyone think that I'll have a problem using this cam? I would hate to buy the cam, then having valve to piston clearance problems after the cam has been lubed and installed.

Any help and/or input is thanked in advance.

Thanks guys.

Don't know about the valve to piston clearance,but the cam will like 10 to 1 comp to 10.5 to 1,you will be to low with 9 to 1. graemlins/waving.gif

Total lift means very little while trying to determine piston to valve clearance. At full lift the piston is way down in the cylinder. You need to be concerned at (+-)10ºbtdc and 10ºatdc. The ramps,duration and valve timing are the determining factors.

I know someone that runs those pistons (and with less than .010 piston/deck height too I believe) with a larger cam than that and #215 heads.

Thanks for the input guys.

Would a steel shim gasket damage your alum. heads?

Originally posted by phel69:
Would a steel shim gasket damage your alum. heads? =

No.
===

And Jim is right about the p/v clearance, it is duration & lobe seperation along with where the cam is installed that determines clearance but it is around TDC overlap not TDC compression ;)

A few other things that will make a difference would be the actual head casting, how many valve jobs have been done, how much material has been removed off the heads.
Along with gasket thickness, deck height, ect.


What this all means, is that you NEED TO CHECK IT, period, no if, and, or but.

I can answer your question directly. I ran exactly that cam and those pistons in my 468. Sorry to say this, but we had to fly cut the pistons. I think the intakes only and had to take about .070 cut.
I have those pistons with rods etc sitting, need to sell them. Have the cam too In fact have the whole rotating assy for sale including the ATI balancer.
FWIW....the combo with EDEL oval port heads, dart intake and a 950 made 560hp and powered my 69 Nova to high tens.
Ron....now doing a 498

Originally posted by Ron454:
I can answer your question directly. I ran exactly that cam and those pistons in my 468. Sorry to say this, but we had to fly cut the pistons. I think the intakes only and had to take about .070 cut.
I have those pistons with rods etc sitting, need to sell them. Have the cam too In fact have the whole rotating assy for sale including the ATI balancer.
FWIW....the combo with EDEL oval port heads, dart intake and a 950 made 560hp and powered my 69 Nova to high tens.
Ron....now doing a 498 Ron,

What was the cost to fly cut the pistons? I'm curious as to what the cost is vs. getting, right from the get-go, a piston from one of the other mfg.'s that won't need the fly cutting. SRP or Ross supposedly has a piston that will take higher lift cams.

Rod

I might just step down a cam size, maybe these UltraDyne solid grinds:


282/292 adv, 248/255 @0.050", .570/.586" lift, 112 LSA

OR

285/295 adv dur, 252/261 @0.050", .595/.595" lift, 110 LSA

I know for a fact that the .595" lift cam will clear because a buddy is running the same cam, with the same pistons. And his pistons are 0.005" above the deck (0.039" head gasket). [/QB]Fly cut the pistons....a cam with .575" of lift can have more clearance problems then a cam with .675" of lift.(trust me...I learned the hard way)

Can't remember exactly what itt cost to cut the pistons, but $125 sticks in my head. That was some time ago.
God luck!
Ron

Originally posted by bluerebl:
Hey guys, I just bought some TRW L2399 (0.030) 454 pistons from another TC'r (Epistuff).

I started thinking about something. What is the max lift that these pistons can handle? These pistons are replacement '71 LS-6 pistons that will give me around 9.0:1 CR. Perfect for my street 454, and still great if I wanna hit it with a 150HP of nitrous down the road.

I had planned on using this UltraDyne solid flat tappet grind: Bottom End:

288/296 F10: .612/.630" lift, 288/296 adv, 255/263 dur@0.50", 110 LSA

Does anyone think that I'll have a problem using this cam? I would hate to buy the cam, then having valve to piston clearance problems after the cam has been lubed and installed.

Any help and/or input is thanked in advance.

Cable; I had clearance problems also. That is why I changed pistons. I was running a Crane Hyd. roller though. I bought the engine SUPPOSEDLY all ready to run :rolleyes: . I'm glad I tore it down to precheck. I used K/B 257s but they are only hypertuetic pistons and I don't think that they fit your needs.

I just saw this interesting cam note in the Lunati listing:

Solid Biggest cam for factory 11:1 pistons without notching. Needs headers, 10:1+ CR, 3500 SS or 4-speed. Power 3000 to 6800. 292 302 255 264 0.586 0.586 0.345 0.345 112 108 19 BTDC 56 ABDC 68 BBDC 16 ATDC 402A9LUN

You'll run into valve to piston clearance problems with factory or Speed Pro replacement pistons, with a smaller cam than that one. I have the UD/Lunati L-78/LS-6 replacement cam (238/238, .550/.550) and Speed Pro L-78 replacement pistons. Exhaust V to P clearance is tight (intake side was fly cut). That is with .005 deck and .039 gasket.

To check piston-to-valve before balancing, put the head and gasket on your block, with the cam out of the block. Turn the crank until the piston is at TDC. There should not be heavy valve springs on the head, because you need to depress the valves until they hit the piston.
With the 288/296F10 in the engine at 104° ATDC, the intake valve lifts .200" and the exhaust valve lifts .170" after valve lash. Whatever lift it takes to hit the piston is what is there, and if you subtract your .200" and .170", that is your clearance. I suggest an additional .100" on the intake,--.300" total valve lift before contact, and .120" on exhaust,--.290" before contact.
This system works for all cams, IF you know the lift at TDC at the cam.

UDHarold

Okay guys, tonight I measured piston to valve clearence with a .022" thick GM LS-6 head gasket and my Pro-Topline iron 290cc head(s) w/2.19/1.88" valves.

-Intake valve has 0.2095" of movement from valve seat to piston contact

-Exhaust has 0.3345" of movement from valve seat to piston contact


I was planning to use a 0.022" shim head gasket to get my quench down to .040" and having 10.1: CR.

However I will run a 0.039" head gasket if needed to get alittle more clearence, but would drop my CR to 9.7:1.

So, it looks like the 288/296F10 cam is out of the question.

Harold, what else do you have in the solid flat tappet catalog that will work with the clearences I have to work with? I'd prefer to keep the .022" gasket, but I will go to a 0.039" gasket if needed. I will also step down to a hyd flat tappet grind too if needed.

Thanks Harold.

either you made a typo, measured completely wrong or i am a retard? i think you meant
.295 on intake
.345 on exhaust
which would leave you with
.095 on itnake
.175 on exhaust? still sounds a little weird?

Originally posted by cody:
either you made a typo, measured completely wrong or i am a retard? i think you meant
.295 on intake
.345 on exhaust
which would leave you with
.095 on itnake
.175 on exhaust? still sounds a little weird? Yes, typo (fixed now).

Here is the correct numbers:

-Intake valve has 0.2095" of movement from valve seat to piston contact

-Exhaust has 0.3345" of movement from valve seat to piston contact


Which only leaves me with 0.0095" of intake clearence needed with the 288/296F10.....not enough by a long shot. I have plenty of room on the exhaust side though.

are you sure thats right? my dial indicator doesn't go down to .0001?

Originally posted by cody:
are you sure thats right? my dial indicator doesn't go down to .0001? Its my buddy's, digital.

.095 Intake & .175 Exhaust is perfectly acceptable clearances,especialy when using the checking method described above.

Originally posted by 1968 hot rod:
.095 Intake & .175 Exhaust is perfectly acceptable clearances,especialy when using the checking method described above. But I don't have 0.095" of clearence, I only have 0.0095" of clearence with the 288/296F10 cam.

---------------------------------------------

Okay, I just got off the phone with Steve at Lunati.

We figured out that we can run the 276/284 solid ground on a 114 LSA (instead of 110) and +4* advance ground in as well.

Specs: Extremely popular street/bracket "Sleeper" cam. Good idle and exhaust note, great power. Needs 2500 SS converter, 3.23 or better gears. Power 2500 to 6800.

276/284 adv dur, 243/251 dur@0.050", .586/.600", 110 LSA

i am pretty sure you are confused about your measurements but i coiuld be wrong?

Originally posted by cody:
i am pretty sure you are confused about your measurements but i coiuld be wrong? No offence intended Cody. You are mistaken, the measurements are correct.

The guy who took the measurements for me has been a machinist for 35 years. What we were doing last night was pretty simple stuff.

I had this problem with my motor, I bought a tool made by Iski cams and cut the valve reliefs myself.
Mine is made for a 2.19 valve, but you can get other sizes.
You do it using the head as a guide, works really well.
No big deal, just alot of measuring and remeasuring.
FYI my tool is now for sale..... hint, hint...
T.C.

Thanks for the offer, but cutting the pistons would throw off the balancing.

Besides, I am pretty happy with the cam I'll end up using.

You wont be happy with 114 lsa for drag racing. And maybe I'm missing something, but how do you measure P/V clearance with no cam installed? If the machinist ASSUMED these measurements at TDC, w/o cam, ??? Can't be?

I'm not trying to be a jerk, just hopefully learn something. The valve is well off the seat as the piston nears TDC, thats where the problem is, NOT at TDC. Tighter the LSA the closer that valve follows the piston up. And you need a lobe profile, phased correctly, and a rocker ratio to measure it.

or so I thought, but I learn something new everyday, Lord willin'....

Remove stupid post after thinking aout it. graemlins/clonk.gif

Originally posted by 427L88:
You wont be happy with 114 lsa for drag racing. And maybe I'm missing something, but how do you measure P/V clearance with no cam installed? If the machinist ASSUMED these measurements at TDC, w/o cam, ??? Can't be?

I'm not trying to be a jerk, just hopefully learn something. The valve is well off the seat as the piston nears TDC, thats where the problem is, NOT at TDC. Tighter the LSA the closer that valve follows the piston up. And you need a lobe profile, phased correctly, and a rocker ratio to measure it.

or so I thought, but I learn something new everyday, Lord willin'.... Its no biggie Gene, we just did EXACTLY what UDHarold said to do earlier in this topic:

Originally posted by UDHarold:
To check piston-to-valve before balancing, put the head and gasket on your block, with the cam out of the block. Turn the crank until the piston is at TDC. There should not be heavy valve springs on the head, because you need to depress the valves until they hit the piston.
With the 288/296F10 in the engine at 104° ATDC, the intake valve lifts .200" and the exhaust valve lifts .170" after valve lash. Whatever lift it takes to hit the piston is what is there, and if you subtract your .200" and .170", that is your clearance. I suggest an additional .100" on the intake,--.300" total valve lift before contact, and .120" on exhaust,--.290" before contact.
This system works for all cams, IF you know the lift at TDC at the cam.

UDHarold So, when I found out I would not be able to use the 288/296F10, I called Steve @ Lunati as per Harold's suggestion. He took my measurements and we figured out that the 276/284 would just barely work if ground on a 112 LSA and set 2* advanced. He asked if I had planned on using nitrous, I replied I will in the future. So, just to be safe and work better with the nitrous, he suggested we step up to a 114 LSA for more P/V clearence, but also advance the cam to 4*.

I am by far a cam designer or grinder, I am just doing what these pro's have been telling/suggesting for me to do.

Cable,
Install the camshaft and degree the cam,do not remove pointer.
Install the heads with light springs and head gaskets you plan to use,set lash.
Find tightest clearance and mark this on your degree wheel with masking tape.
Remove the head install 2 outer valve springs on the valves you intend to check with.
Reinstall head,pushrods,and rocker arms,install 1" travel indicator on spring retainer then rotate engine to degree wheel marks you made O indicator.
Compress valve spring using the Polylock and box wrench to get your clearance.
Hold on to your Breaker bar,the motor will want to spin a little when using this method.
.060 Intake is all you need,when the intake valve deflects it gains in clearance opposed to the exhaust loses clearance.
Good Luck

I had this problem with my motor, I bought a tool made by Iski cams and cut the valve reliefs myself.
Mine is made for a 2.19 valve, but you can get other sizes.
You do it using the head as a guide, works really well.
No big deal, just alot of measuring and remeasuring.
FYI my tool is now for sale..... hint, hint...
T.C.

How much? PM me with details. Thanks!!

Hi!

I got those lw2465f in my 468, I am right now (like I go back in the garage after this msg!) cutting a .070" notch with a Isky tool (Havin' a bad experience with that tool!) to clear my Comp Cams 294s (248@.050, .595" lift) with 119cc 049 heads

Piston to deck height is -.010 with a fel-pro gasket (.039"), I end up with a 9.6 cr (Damn!)

Goodday!

I had the same problems with the 2465 pistons. Tried 3 cams (lunati bracketmaster .549/.559 lift, comp 280 magnum & comp 282 solid). All had the same amount of clearance (none). My heads were shaved .030. I ended up cutting the pistons .050 & intalling the cam only 2deg advanced.

I called TRW & they said don't cut any more than .050 into the top of the piston.

Next time different pistons.

Hey guys, digging up one of my old topics.....

I ended up going with Lunati/UltraDyne solid A2 : http://www.holley.com/402A2LUN.asp

Works fine, but maybe its been awhile but it seems to have alot of rocker arm noise, not so much while idling, but when rev'ing it in neutral and controlling the throttle at the carb. I really can't hear anything in the car due to the loud exhaust that exits just behind my seat. The throttle response is great, very snappy and crisp. I am running Crower Stainless Rocker arms and I have triple checked my lash (calls for .020/0.022"). I set them cold at .022/.024" as suggested my many on this board.

I have over 1000+ miles this cam without a hit of problems. I broke in the cam (and motor) without the inter valve springs and drove around for 300 or so miles until I put them back in. The engine short block was already broke in from a previous build. To date I haven't rev'd the motor over 5000 RPM because I am worried about breaking something. I guess I am getting more paranoid as I get older......

I know the ticking isn't exhaust leaks because I am running copper header gaskets and aluminum collector gaskets, plus I took a smog sniffer to the engine compartment and no leaks were found. Plus the noise is clearly coming from the valvetrain area.

My dad thinks I am hearing more than I should because I have super thin stamped aluminum Moroso valve covers and they 'echo' more and dampen less noise than a steel or thick cast aluminum valve covers would.

Anyway, would tighting up the lash help? If so, how much tighter should I run the valves?

I am getting to the point where I am considering swapping it out for a hyd flat tappet Voodoo grind.

Suggestions and/or comments?

they will hit! i tried it with a comp 294 s and had .040 on the intake. you will have to cut the valve releif on the intakeside of the piston an extra .100 will work fine. and there is plenty of meat on the piston to do this. ray

I am not sure what you mean, which part do you mean?

The only way to know if you will have to fly cut your pistons is to put your motor together with old head gaskets,the same thickness you plan on using and turn the motor over two complete revolutions by hand and check piston to valve clearance.You need .080 on the intake and .100 on the exhaust min.WE who build motors on a regular basis accomplish this by sticking modeling clay or playdough to the piston and lightly oiling the face of the valves and slowly turning the motor over. check,check,check.
As mentioned before lift is not as big a factor as is duration and opening and closing of the valves in camshaft degrees.Cams with as little as 4 degrees differences can have major effects on cam timing in relation to piston clearance.And although the piston chases the exhaust valve,that doesn't mean that the intake valve will always be OK.If the valves kiss the pistons you will know it.We also use Fel Pro MLS head gaskets.They are pricey,but work extreemly well, even on the hose.Do not use steelshims with Alum.heads.And make sure you torque all ARP bolts and stud nuts at least 5 times before final torquing.ARP says this in the instructions....

The only way to know if you will have to fly cut your pistons is to put your motor together with old head gaskets,the same thickness you plan on using and turn the motor over two complete revolutions by hand and check piston to valve clearance.You need .080 on the intake and .100 on the exhaust min.WE who build motors on a regular basis accomplish this by sticking modeling clay or playdough to the piston and lightly oiling the face of the valves and slowly turning the motor over. check,check,check.
As mentioned before lift is not as big a factor as is duration and opening and closing of the valves in camshaft degrees.Cams with as little as 4 degrees differences can have major effects on cam timing in relation to piston clearance.And although the piston chases the exhaust valve,that doesn't mean that the intake valve will always be OK.If the valves kiss the pistons you will know it.We also use Fel Pro MLS head gaskets.They are pricey,but work extreemly well, even on the hose.Do not use steelshims with Alum.heads.And make sure you torque all ARP bolts and stud nuts at least 5 times before final torquing.ARP says this in the instructions....
=
Well Eric,,
We who build engines are not exactly in complete agreement here:)
First off there is no good reason to have any where near .080 on the intake side for clearance in almost all applications & if there is I for one am in huge trouble with a lot of engines I have done.
I have run .040 & in some cases less to 9000+ with no issue in engines with good valve control.
The intake is opening & under the control of the spring any time it is anywhere near the piston, the exhaust is a completely different story,,

Second, I rarely ever use clay & most of the professional engine builders I know do not use clay for p/v clearance but it most certainly can be used if that is your desire.

Third, I have run the FelPro 1094 on numerous occasions with aluminum heads in both street & circle track applications to 13.0+ compression with no issues as long as the block & head was finished properly.

As for MLS, I completely agree that they are excellent gaskets with the proper surface finish which a lot of shops cannot achieve.
These are usually the ones who have problems with them.

And I agree that all fasteners should be cycled 3-5 times to "burnish" the surfaces of the bolt, nut, washer, whatever so you get a true torque reading unless you are using a stretch gauge as in a rod.

Wolfplace,I apreciate your input and although we use different clearances,would you not agree that if we built our own motor and took what someone else said, "would work",without checking it first then we get what we deserve.I understand that some motors use tighter piston to valve clearances,tighter squish areas,and so on. I was just trying to give a general rule of thumb.
If you don't use clay then what do you use?Willing to learn.
I sit and read magazines all the time and wish that everything was not so top secret,that maybe we could each learn a little something new.Cam specs are usually one of those top secret things, and although it may work well in your car ,doesn't mean it will work in mine.I love going to the drag strip and learning about different cars.Not just Chevys mind you,but Fords and Chrystlers too.I've learned alot about cars from talking to different people.
Thank you,Eric.:thumbsup:

Wolfplace have a question,Have you ever ran a motor without roller cam bearings and then with them to see how much power they are worth.
Thank you.

Wolfplace,I apreciate your input and although we use different clearances,would you not agree that if we built our own motor and took what someone else said, "would work",without checking it first then we get what we deserve.I understand that some motors use tighter piston to valve clearances,tighter squish areas,and so on. I was just trying to give a general rule of thumb.
If you don't use clay then what do you use?Willing to learn.
I sit and read magazines all the time and wish that everything was not so top secret,that maybe we could each learn a little something new.Cam specs are usually one of those top secret things, and although it may work well in your car ,doesn't mean it will work in mine.I love going to the drag strip and learning about different cars.Not just Chevys mind you,but Fords and Chrystlers too.I've learned alot about cars from talking to different people.
Thank you,Eric.:thumbsup:
=
Hi Eric,
I use a dial indicator on the retainer & I measure every couple of degrees from 5 atdc to 20 atdc for the intake & 20 btdc to 5 btdc for the exhaust
I start with about 5 degree increments & then narrow it to 1-2 degree increments where the valve is closest.

Or you can also use solder strips but to me, clay is a pain in the ass.
You have to spray the valve & deck with WD 40 or something & the clay still sticks half the time, it also will "bounce" back giving a slightly false reading.
It can be a bitch to get an accurate reading sometimes & I for one don't like taking the head on & off & doing this ten times. :D
Clay can most certainly be used but it is not my material of choice.

You have to consider what the valves & pistons are doing, not just what someone tells you.
What is the intake valve doing when the piston is anywhere near it?
What is the piston doing at this same time?
Now,,, what is the exhaust valve doing?
Which one is going to lose control or bounce off the seat at these points?

Think about it, don't just take someone's word for what you need.
I have one engine that regularly goes to 9000 many times during a race that has intake p/v clearance that is about .025 when cold, about 035-037 hot.
This is with the valves set
It has never tagged an intake.
I AM NOT RECOMMENDING THIS HERE FOR THE AVERAGE ENGINE

Now,,, if you take an engine with hyd lifters you had better add the amount that the lifter can "pump up" to your equation or you may not like the results.
If you had a 7/16" stud & one turn of load you need to add .050 to your minimum numbers.
Now the .080 minimum is a pretty "safe" one on the intake not taking into account the ratio of the rocker.
In reality if you had .050 of preload in the lifter you would move the valve .075" with a 1.5 rocker if the lifter "pumped up"
So,,, the valve is now open .075 under massive float.
If it were a rat the valve could be open as much as 85 thou,,,
If you only had .080" things get real interesting,,.
Way more to this stuff than a simple .080 is safe, .050 is not ;)

Now,,, another thing to bring into the mix.
If you have .050" clearance with checking springs you will have substantially more with the real springs especially with a roller with the springs necessary to control the valvetrain.
I have measured as much as .020 difference between checking springs & ready to run stuff.
The good news is the clearance always get bigger.

Wolfplace have a question,Have you ever ran a motor without roller cam bearings and then with them to see how much power they are worth.
Thank you.
=
Nope but it has been done & my understanding from pretty reliable folks is there is very little to be had here just due to the roller bearings.
The big advantage besides the obvious strength of the bearings with hi spring pressures is what could be done with oil control.
You do not need pressure oil to the roller bearings like you do with a Babbitt type bearing.
The engine will turn over easier in a static condition with the roller bearings but when running you have a film of oil on the conventional bearing so the differences in friction are probably pretty minimal.

I also think that the oil control in some cases is no longer valid either considering the cup guys are running the cam in a full oil bath in an enclosed "tunnel" in some engines to make it live & pumping the oil out of this "tunnel" as is done out of the valley & or heads.
Others are spraying the lobes,,, all kinds of "tricks" that they ain't sharing with us mere mortals :D

It takes a lot to make a flat tappet valve train go to 10,000 RPM & live regardless of all the internet stories about the 283's that were regularly shifted at 8000 with "Z28" springs & stock parts,,,, :sad:

Cable, I have that same cam and I have been running it lashed at .018 & .020 cold in my 498. I also noticed that when I lashed it at the card specs it was a little noiser than I liked. I think I recall Harold saying that you can go .008 tighter than the card specs without getting into trouble. I have run it it as tight as .015 & .017 cold on my last outing to the strip to confirm my thought that the 498 wants more cam.