Help identify cam please

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kingvern

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I bought a TRW cam a few years ago and I can’t find the cam card. The numbers on the end are. 2K157 then below that 153. The part # on the box is TP156
 
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I have some old trw catalogues but I'll have to find them they are in storage
what motor, year range etc
 
TP156, small block, Hydraulic, .450, .475 lift, 321*, 331* SAE duration, 102* overlap, 107, 117 lobe centers, Events at.050, intake open 9*btdc, close 43* abdc, exhaust open 58*bbdc , close 4* atdc
 
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lots of duration and low lift for unported stock heads and springs
stock 340 cam is about 209 on the intake @.050 so this one is a lot more duration
do you have high compression? if so if you have gears and a converter you could try it
but it costs mid range compared to a modern cam
design is around 40 years old mfg quality good if this is new
has 112 lca stock was 114 but stock 340 has really long ramps which the 114 helps hide and also bleeds off excess compression/ dynamic compression

post up your complete build and someone like NM or AJ will run the numbers for you
what's your cranking compression now and what is your current cam?
most likely this is similar to a "white box" cam and may be a copy of some popular GM cam put on a Dodge billet
The .050 evens are only useful for "degreeing" the cam using the .050 lifter rise method
seat timing determines how the cam works some other vendors using that grind have SAE seat timing
which incidentally is at .004 cam lift with 1.5 rockers (.006 at the Valve) (same lifts Crane uses)
the much longer exhaust was due to the poor relative flow of the exhaust on the LA heads- especially with a stock exhaust (no headers)
If you have newer/ ported heads and /or headers you do not want that much additional exhaust duration
end of rant
 
To answer what's it good for
depends on your build
In a stock early "high compression" 340 it would give you a hot rod cam sound, be dead off the line without low gears- be ok passing on the highway when you kick it down
would be a real PITA without converter and gears or in a later 340 or any 360 or 318
RRR has a point but you have to have the right combination
in a low compression motor or stock geared you would have to wind the snot out of it and be disappointing if you dont
those cams are reliable- designed for the springs of yesteryear - you could use 340 springs
They leave a tremendous amount of area under the curve on the table compared to a Mopar street cam like say Engle or Mopar Performance
and even more for a higher rate cam like the Comp XE HL series which would require head work on stock heads due to the lift
Lunati Voodoo is in between
so how do you want to drive it?
 
Camshafts cannot bleed off cylinder pressure. That's incorrect. The later the IVC event, the less cylinder pressure there is, so it simply makes less pressure to begin with. Not the other way around.
 
Engine is a 73 10-1 compression stock heads. Stock crank. Rods, currently has a comp cam.
Lift is 474/473
Duration 284/296
Centerline 106
Lobe separation 110
Advance 0*
RPM 2200/6000
Stock converter and gears in a 1979 F body.
Car is my 17year old sons that we are building for him
 
That cam is like the old school cheater cams. I wouldn’t use it for anything but a super stock build. It will need very steep gears and a very hi stall converter as in 4500 at least. Kim
 
Yeah that's a lotta cam for a stock converter. I agree with kimmer too......it's WAY out of its element. I would choose another more suitable grind.
 
kingvern said:
Engine is a 73 10-1 compression stock heads. Stock crank. Rods, currently has a comp cam.
Lift is 474/473
Duration 284/296
Centerline 106
Lobe separation 110
Advance 0*
RPM 2200/6000
Stock converter and gears in a 1979 F body.
Car is my 17year old sons that we are building for him
Click to expand...

The thing is; your 284/296/110 cam doesn't actually close the valves where you might think, either. The advertised numbers are usually taken at .008 tappet lift, or Comps are usually at .006 tappet lift. But the actual on-the-seat and not-leaking points can be waaay on down the line. Perhaps(I'm guessing) even 15 degrees on down the line at each end making your 284/296 into a true 314/326/110..
Also;FYI; if you have a 110LSA cam installed at 106, then it is 4* advanced. The advance may have been ground into the cam and so perhaps it fell in at 106 with no additional fudging, but none-the-less, in at 106 is 4* advanced, on a 110LSA cam. Jus saying.
If the above cam makes at least 155psi cranking cylinder pressure, then it will be fairly peppy with a true 2450 stall TC;but I don't think any 79 TC is gonna work.
If the car has 3.23s or less;you will come to dislike those intensely, because the power doesn't wake up until around 4800 rpm, which in first gear with 3.23s, is ~ 46 mph. So install some skinny tires and let her rip.
And also if the pressure is significantly less than 150,then you might find the bottom-end soft. A true 10.2/1 Scr is about right for that Comp 284/296/110cam.
That's a pretty big street cam for a 17 yearold. Getting sideways at 40+ mph when the cam hits, can lead to catastrophic results. Put some 4.30s in there and the power will hit around 30/35, then some 295s so he can brake while going sideways, then a hidden rev-limiter........ jus saying,lol.
 
Ah yes, the TRW TP line. It was Trw's performance parts. That's a powerful cam for sure. I sold a lot of them decades ago. (along with gears and converters) We only had B&M back then. Probably a Super Holeshot. Enough reminiscing.
What's wrong with the cam you have in now? Too big for the gears and stock convertor?
 
Yes from what I’m reading both cams are to big. My son is going to be driving it everyday. And we all know how a teenager drives when out of site. He already thinks he is a race car driver. Don’t want to give him too much.
 
kingvern said:
Yes from what I’m reading both cams are to big. My son is going to be driving it everyday. And we all know how a teenager drives when out of site. He already thinks he is a race car driver. Don’t want to give him too much.
Click to expand...
With your combination it sounds like a cam closer to stock 340 specs would be a better choice.

It sounds like you just have a stocker and don't need maximum performance or you're not building a race car.
 
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Much better cam choice if you already own it
72 340 went to 8.5 compression (advertised- really under 8) do you have the early pistons? if so maybe 9+ : 1
run that cam and see how you like it if it's already in the motor
compare the specs with the newer XE274HL
as with the TRW cam you do not need that longer exhaust with headers or heads with a better than stock flowing exhaust port
check the tag on the differential and report gears
with 110 LCA in at intake centrline of 106 is 4 degrees advanced
I also agree that the COmp is also too big
ixnay on the stock 340 cam or the comp 268
answer the compression question if you can
Lunati voodoo line would be a benchmark for off the shelf cam as even the Comp XE274HL may (most likely) be too big depending on gears and compression and that's the only choice from comp unfortunatly
 
once you get back with the compression and rear gear we can be more helpful
take a look at this 360 AMC) dyno chart which give more of a "engine masters' torque curve
this is a 256 @.006 cam (with really short actual seat timing)
then figure how each duration size increase lowers the low end and moves the curve up
you can see how big comp 284 is for a stock gear and mild converter
lots of other good advice above

Hi Wyrmrider!

The motor's been dyno-tuned. Here's the dyno chart. I'm pretty happy with the results. 417 peak TQ at 3700 RPM. That's pretty good for a motor with a fairly stock idle, good vacuum, and assuming longevity. What surprised me was the extent of the power band: 90% of peak TQ from the bottom of the chart (2800) to 5100. 363 HP at 5000. 90% of peak HP from 4200 to the top of the chart (5200).
The HP peak had a bit of a nice mini-band, too. I bet the thing would have had 350 through 5500 or so.
The tires will not be happy about this. By the way, my name is Maurizio.
 
Engine was rebuilt and 10:1 compression pistons with stock heads. Rear end is stock 7.25 not sure on gear. Non sure grip. Second cam mentioned is in the engine. Sounds like he is going to need a converter and rear end with some gear.
 
I have to admit, cam too big, cheater or whatever, if I already HAD it, I would run it. You can make it perform better if you advance it a lot. It's on a 112, so I would advance it down around maybe 102.
 
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