Another Cam Suggestion

Hi Guys, working on a 355 I want to build for the street to have fun but really stumped on cam technical stuff I don't understand. So I'm asking for your feedback please.

First, what I've got, 350 +0.30, 2 piece rear seal, 4-bolt, hyper dished pistons, moly rings, ARP rod and main bolts, 7 qt. oil pan, 10/10 crank, new balancer and sfi flexplate, (dished pistons so I can run 9.0:1 with a 64cc head),
air-gap intake, (Professional Products for use with or without vortec heads), 1-5/8" headers, 2-1/2" full exh w/Flowmasters, Holley 650 dbl. pump.

I need my topend, alum. heads, ('cuz I want alum. heads), Trick Flow, Edelbrock E-Tec 170, 200 or RPM, not AFR out of my price range and too overkill for what I'm using this engine for. Going in a 3500 lb. car with 3.89:1 gears, 200R4 trans with 2200 stall. Mainly street use, shows and cruising, want to do powertour next year so I want it to sound good! Have manual four wheel disc brakes, so no concern for vacuum, but do have Vintage Air.:cool:

Was looking at thumpr cams, love the sound but costing me power! U-Tube videos on them are quite convincing. Hyd or hyd. roller- much sound difference?

Sorry for the long description, just hope I didn't leave much out.

Thanks.

Hydraulic roller will have more valve noise, they can also have more aggressive profile for any given lift since they are not limited like a flat tappet is. I doubt if the engine exhaust not will change unless you really go big.

Keith

Either Trickflow or Edelbrock RPM heads would be a good choice for a street thumper. You can't go wrong with either one. I had a 355 a few years ago and I liked the CompCams Magnum 270 cam I had in it. If you have a roller block, I would recommend the roller version of the Magnum 270. Otherwise, go with the flat tappet cam. In my opinion, the cost of a retrofit hydraulic roller is not worth it. But, hey . . . it's your checkbook!

sbc use the hydraulic flat tappet cams, I use the Comp Cams 280/480 and love it. People right here on this site recommended it to me and they were right.

I have the Magnum 280 in my 383, and for me, it is just right. In a 350, it would be a little lumpier than I like personally, but that's a matter of prsonal preference. The Magnum series is often overlooked because of the popularity of the XE series, but the Magnum cams make great power and torque, and you can use them with a little more static compression than the XE cams.

Thanks for the feedback guys !

Thumpr cam is now out, Looking into the Edelbrock e-tec 200 and
XE 256H .447/.454 1,000-5,800 rpm
XE 268H .479/.480 1,800-5,800 rpm
Mag 280H .480/.480 2,000-6,000 rpm

Now I need roller rockers, should I get 1.5 or 1.6 ?

What benefits will that give me other than more lift with the 1.6?

Just a rookie learning.:o

Quote:

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Originally Posted by kool

Thanks for the feedback guys !

Thumpr cam is now out, Looking into the Edelbrock e-tec 200 and
XE 256H .447/.454 1,000-5,800 rpm
XE 268H .479/.480 1,800-5,800 rpm
Mag 280H .480/.480 2,000-6,000 rpm

Now I need roller rockers, should I get 1.5 or 1.6 ?

What benefits will that give me other than more lift with the 1.6?

Just a rookie learning.:o

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There is no need to go with 1.6 rockers if this is a street engine. Now if you were going to be drag racing, that is a different story. You might also take a look at CompCams XE 262H. The XE 256H is a little small to really get the benefit of the Edelbrock heads you are considering. The XE 262H and 268H are popular grinds, and past comments from people using these grinds in 350's have been very positive. The 268H is a more aggressive grind but it should work fine with your 2200 stall converter. With the Magnum 280, you might want a little more stall than 2200. The 268H definitely has a nice sound that I think you would like.

Thanks Lynn!

I'm going to look into the XE 268 H (CL12-242-2).

I was reading this article that was using this cam. Anything you might want to point out for me?

REALLY appreciate this help Lynn.

http://www.compcams.com/information/...HP0401-001.asp

Here is the other article they mention in the first article.

http://www.compcams.com/Community/Ar...?ID=-548756935

Quote:

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Originally Posted by kool

Thanks Lynn!
I'm going to look into the XE 268 H (CL12-242-2).
I was reading this article that was using this cam. Anything you might want to point out for me?
REALLY appreciate this help Lynn.
http://www.compcams.com/information/...HP0401-001.asp

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Just a couple of points to help with your education.
Since the reformulation of motor oils and the removal of extreme pressure lubricants, it is an extremely iffy proposition to run a flat tappet cam. Howards has some acceptable hydraulic roller grinds that will retrofit into an early block for less than $500. If you think $500 sounds expensive, just wait until you frag a flat tappet cam and have to yank the motor all the way down to a bare block again to remove all the shrapnel from the oil galleys.

Of course, a much better alternative is to begin with a roller block. '96-'00 Chevy trucks and vans used a Vortec 5700 350, regular production order number L31. The heavier duty models of these motors used a 4-bolt main, but you won't need 4 bolts at the power level you're considering with this build. I have found short blocks here in Phoenix for $200, although they are beginning to get a little pricey as the word on them gets around. You can re-use (in most cases) the factory roller tappets, dog bones and spider, rods and crank, having to purchase only the cam of your choice, pistons, oil pump and gaskets.

Use only 1.5 rockers on a street build. 1.6 rockers will add less than 10 hp, but will add considerable stress to the entire valvetrain.

You didn't say what pistons you will be using, but you should pay particular attention to the article you linked about using the D-cup pistons. If the pistons you are using have this configuration, then you are good to go. If they have a full circular dish with very little flat area on the crown to mate up with the underside of the head, then you will not be building the optimum motor and may experience some difficulty running on lesser grades of fuel when using optimal ignition timing. I have included photos of a less-than-optimum crown design dished pistons using a circular dish and a very thin flat area around the perimeter of the crown. Compare these photos with the one in the article and you can see that they used a piston with a considerable amount of flat surface to accomplish a good squish (D-Cup piston).

I have run the XE268H cam in a 9.00:1 350. It is not a lumpy cam and you will more than likely have to drop the idle down pretty low to get any lump-lump at all. It is a great street cam though. Makes good torque to move a heavy car. Now here's the thing. All you guys who are building your first or one of your first motors want the lumpy sound of a race motor. Street motors don't sound like that. Race motors sound like that. If you're building a race motor, then build it 10.5-11.0 to 1 and use a 290 degree cam (240 @ 0.050") and put up with its ill street manners, high stall torque converter, stiff rear gears, transmission cooler and crummy fuel mileage on premium pump gas. You'll be sick of it in a few weeks, but boy oh boy, it'll sound good to the geeks down at the drive-in who don't know any better.

Dump the intake and use a Edelbrock RPM or Weiand Stealth. Either of them will be worth 40 hp over the manifold you have now. You didn't say about the headers, but use only full length, tuned headers. Block huggers and other shorty headers are a waste of money in my opinion. You might just as well use those fosdick OEM cast iron manifolds.

12cc pistons with zero deck, 64cc heads and 9cc gasket will yield 9.55:1 SCR. 18cc pistons with zero deck, 64cc heads and 9cc gasket will yield 8.99:1 SCR.

Oh, and I use "fosdick" a lot. It is synonymous with bogus or lame. Fosdick was a character in the Dick Tracy comic strips.

Oh yeah, about heads. Here is a great head for the money. 0.550" max valve lift (street friendly). Will make 400 hp, 450 ft/lbs @ 9.5:1 SCR with a mild cam.
http://www.summitracing.com/parts/EDL-5089/

Scorpion makes a high-quality roller rocker arm with roller tip and roller fulcrum that is affordable. Don't be fooled by the Comp rockers that us a roller tip and ball/socket fulcrum. Fosdick.

The motor will be much easier to drive with a vacuum-secondaries carb. The rule of thumb is....vacuum secondaries if the converter stalls at less than 3000. Double pumper if the converter stalls at over 3000 or if the trans is a stick.

Lots of great reading techinspector1 !

The way I look at it, post a question and real people give their real world experiences, not like advertisements that just sell you stuff. Real good info and thanks again.

I do have the KB-142-030, the d-cup piston, going with 1.5 rockers, sold on the e-street heads, (idle-5500 rpm), can't believe I dismissed them, XE-268-H (1,800-5,800 rpm), or XE-274-H (2,000-6,000 rpm) kind of undecided.:(

Most likely the XE-268-H, rpm closer to heads and stall.

You mentioned that the oil formulation isn't there anymore for use with flat tappet cams like it once was. What oil do you reccomend for break in and regular oil changes.
Oh, by the way...I live in Canada....eh?

Feel free to comment more, will be ordering stuff in a couple of weeks!:cool:

I am no cam guru and I am not sure of the static compression ratio you have with your combo ,but if it fits into the compression you will have ,The XE-262-h is a great cam ,with a set of rhodes or similar lifters to gain even more torque.

The rhodes lifters will kill off some of the lope sound ,but a lower idle speed will cure most of that.
I set my lifters kinda tight with the rhodes ,close to a solid lifter ,so it kinda loses some of the bleed down at low rpm,still keeps most of the lope ,but gives me more lift and duration at the upper rpms.

Quote:

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Originally Posted by kool

Feel free to comment more, will be ordering stuff in a couple of weeks!:cool:

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OK, I'll comment more. DO NOT USE A FLAT TAPPET CAMSHAFT, REPEAT, DO NOT USE A FLAT TAPPET CAMSHAFT.
If you were aware of the number of flat tappet cams I see roached, you wouldn't even consider one. It's not just the fact that the cam and lifters are ruined and you have to buy them again, it's the fact that the motor has to be removed, completely torn down and all cracks, crevises and oil galleys must be cleaned just like they were when you first put the motor together. So, there's the cost of new cam and lifters, all new gaskets, all the cleaning, re-assembly and the possibility that it will happen all over again. I know there are those of you who have successfully used a flat tappet camshaft, or know someone who has, but everything must be absolutely perfect to prevent wiping a lobe. It's just not worth the gamble when a roller hydraulic camshaft and roller lifters aren't that much more money. I'm going to suggest a Howard's CL110235-12 retrofit cam for you with an intake closing point that will match up with your 8.99:1 static compression ratio. You don't want to use any more cam than this with your low SCR. If you want to use more cam, then change the pistons to 12cc units and use a Howards CL110245. Howards are a little less money than some of the other manufacturers, but still have the reputation of being an excellent product and have been for many years. DO NOT USE A FLAT TAPPET CAMSHAFT.

OK, here's how I would do it.
350 bored +0.030". Cut block decks parallel with main bearing bore for zero deck. (piston crown exactly even with block deck with piston at top dead center), (approximately 9.001" block deck height). The compressed thickness of the head gasket then becomes the squish measurement.
Stock 350 crank, -0.010"/-0.010" OK.
Stock 350 rods with ARP bolts. Re-sized on the big end.
http://www.summitracing.com/parts/ARP-134-6003/
If I wanted to spend a little money on rods, I'd buy Scat I-beam forged Pro Stock rods. They're already clearanced for cam clearance with a stroker crank (3.750") in the event you wanted to use them later on a 383 build and are good to 500 hp.
http://www.summitracing.com/parts/SCA-25700P/
Keith Black hypereutectic D-cup pistons. Use 0.0015"-0.002" piston to wall clearance. Measure piston perpendicular to wrist pin, directly even with bottom of balance pad. Set top ring gap to 0.026"/0.027", second ring to 0.018".
http://www.kb-silvolite.com/kb_car/clearance_pop.php
Aluminum heads require special head gaskets to prevent brinelling of the head.
http://www.pbase.com/image/25091801
Use only the head gasket that Edelbrock recommends. In most cases, the Fel-Pro 1003 is a good candidate, but again, use only the gasket recommended by the manufacturer of the cylinder heads.
http://www.summitracing.com/parts/FPP-1003/
Howard's CL110235-12 retrofit roller tappet hydraulic cam and kit. 214/218, 270/280, 0.488"/0.495", 112 degree lobe separation, cam timing events 0/34/46/-8.
http://www.competitionproducts.com/C...products/1654/
Use whatever thrust button you like. Here's a nice roller button....
http://www.competitionproducts.com/R...ductinfo/8140/
This installs between the nose of the camshaft and the inner timing chain cover to prevent the cam from walking back and forth. Some fellows might prefer to use a solid nylon button to prevent roller bearing failure of the roller button. Lacking information to the contrary, install the button so that the cam will move 0.008"-0.010" in and out. Some fellows will use an aftermarket timing cover that is less susceptible to bending than the stock sheet metal cover as the cam button pushes against it. I've also seen fellows weld a piece of flat metal (like maybe 0.100" thick) onto the inside of a stock cover to strengthen the cover. You can also step up and use a cast cover with a window that will allow easy cam advancing or retarding if you want to. Here's an example....
http://www.summitracing.com/parts/CLO-9-221/
The whole point of the removeable cover is to allow easy access to changing the cam timing. Otherwise, you have to drop the pan to remove the cover to have access to the cam. There are those fellows who will tell you that you can drop the pan down a little to remove the cover without taking the pan off and then work the pan back into position by cutting off a little of the pan rails at the front. I have not been able to do this successfully without having an oil leak at the front after the operation. Do whatever you think is best. If you don't plan on playing around with cam timing, then use a conventional stamped steel front cover with the proper button clearance.

OK, that builds the short block.

I think you have made a good decision to go with the E-Street heads. The valve springs will work well with the cam I have suggested for you. If you can see your way clear to spend a little money on rocker arms, I would highly recommend the Scorpion 1.5 rollers for use with 3/8" studs. The value of these rockers is in the fact that the ratio is correct and that the fulcrum point is roller bearing. Never mind the roller tip, it has virtually no value from a performance standpoint. Standard stamped steel rocker arms will vary from the as-designed ratio by as much as 6 or 7 percent. In other words, a steel rocker could actually be 1.4 rather than 1.5.
http://www.summitracing.com/parts/SCC-SCP1000
I've been playing with my DynoSim software for almost a year now and every street or street/strip build I run through it will make the most hp and torque with a dual-plane, high-rise intake manifold such as the Edelbrock RPM or Weiand Stealth. You will not need more than a 650 carb for your application. Forget those fosdick oil-soaked air filters in my opinion. Use a dry element, minimum 3" tall by 14" diameter.
I might mount an electric pump and good cartridge filter back near the tank, then plumb in a return regulator with a return line to the tank. Out of the regulator, you need only run one 1/2" line to the carb. Set the regulator to max 5 1/2 lbs for a Carter AFB or Edelbrock Performer and 6 1/2 lbs max for a Holley. Not sure about Barry Grant. Call them to find out. If you don't get the fuel pressure under control, you will have tuning nightmare from hell.

Most of you young fellows have been raised with EFI, where more pressure makes more hp. That is not the case with carburetors.

I like a manual choke and usually install them with a microswitch on the choke plate that powers a dash light to show me that the choke is on or off. I do not trust an electric choke. I want to know definitely where the choke plate is at all times.

Use a good set of long-tube equal-length headers with 1 5/8" diameter primary tubes. You can use 1 3/4" tubes to advantage on 383 and larger motors, but 350 and under will work best with 1 5/8". Fabricate an "X" or "H" pipe immediately after the header collectors, before the mufflers, then run 2 1/4"/2 1/2" pipe to the back of the vehicle. 16 year olds and those who don't know any better will terminate the pipes under the vehicle where the drone will make you crazy after a little while. There will be no performance advantage to running the pipes out in front of the rear tires or terminating the pipes under the car. By the time the exhaust gets back that far, it has cooled and contracted enough that there will be no backpressure from the additional tubing going to the back.

There will be no break-in procedure with the roller cam. Wash the lifters and cam with solvent to remove the shipping grease, oil them well with engine oil, install, crank the motor and drive. You can use any type of off-the-shelf motor oil. You will not need oil additives of any kind.
You already have a 7 qt oil pan. Use a good quality oil pump and make certain the pick-up tube is ABSOLUTELY SECURED to the pump. Weld it if necessary. Increasingly, I am reading of more and more fellows losing oil pressure only to find the pickup laying in the bottom of the pan. Adjust the bottom of the pickup so that there is an air gap between the bottom of the pickup and the bottom of the oil pan of around 3/8". A windage tray will free-up a little horsepower and you may want to custom-fit a crank scraper.
http://www.summitracing.com/parts/MIL-32640/

Send your harmonic damper to these guys to be rebuilt.
http://www.damperdoctor.com/
When you get it back, degree it with a tape after determining top dead center.
http://www.summitracing.com/parts/SUM-162591/
Determine absolute top dead center from these instructions with the motor as a short block on an engine stand.....
http://www.iskycams.com/camshaft.php
Make sure you use the front timing cover during the top dead center operation that you will run on the motor after it is together. There are 3 different locations for timing tabs, so if you use a different cover when you bolt the motor together, your entire operation to find and use TDC for ignition timing the motor could be a waste of time.
Set initial timing at the crank to 16 degrees BTDC. Use a timing kit for your distributor that will give you an additional 18 degrees of advance, all in by 2800 rpm's. The motor should not need more than 34 degrees total (initial/centrifugal) ignition advance with the state-of-the-art combustion chambers in the Edelbrock heads. Plug the vacuum advance into the intake manifold, not the fosdick ported vacuum on the front of the carb.

This motor should make excellent power on cat-piss pump gas. I'll run up a DynoSim of the combo when I get more time. Putting this post together has required about 3 hours.

Another of the problems I see constantly is that most fellows have no idea how to adjust the lifters once they are finalizing the motor build. I wrote this for another forum, but will paste and copy it over here for you and others to see....I wrote it so that an idiot could understand it, because I'm pretty sure there will be some idiots reading it.....

ADJUSTING VALVES AND TIMING THE MOTOR INITIALLY AFTER A REBUILD, SMALL BLOCK CHEVY / BIG BLOCK CHEVY. Remove spark plugs. Remove valve covers. Remove distributor. Standing at the front of the motor, at the water pump and looking toward the rear of the motor, #1 cylinder will be on your right, the first one, just behind the radiator. The next one to the rear will be #3, then #5, then #7 will be the last one on the driver's side, next to the firewall. Looking on the other side of the motor, the passenger side, the front cylinder will be #2, the next one to the rear will be #4, then #6, then #8 all the way to the rear against the firewall. Do whatever you have to do to get this all fixed in your mind. If you have to make a diagram on a large piece of paper and sit it against the carburetor, then do it. The importance of knowing which cylinder is which cannot be over-stated.

Also, knowing which way the crankshaft turns and which way the distributor rotor turns cannot be over-stated. As you are standing at the water pump, the crankshaft turns clockwise, the same way the hands on an analog watch or clock turn.

If you were to climb up on top of the motor from the front and look directly down on the distributor with the cap off, you would see the rotor turning clockwise also. See this cute little animation.....
http://www.boxwrench.net/specs/chevy_sb.htm

With a socket and long bar with a ratchet attached to the bolt head that holds the harmonic damper onto the front of the crankshaft, turn the crank clockwise while a friend holds his thumb over the #1 spark plug hole. Using the starter for this operation WILL NOT WORK. When your friend feels air pressure beginning to build under his thumb, that means that both valves are closed and the piston is coming up on the compression stroke of #1 cylinder. Watch the harmonic damper and you will see the notch that is cut into the outer ring of the damper come up to the top. When that notch is at the top, STOP. You are now at approximately top dead center on #1 cylinder. It doesn't have to be EXACTLY at top dead center to adjust the valves.

Make a mark on the harmonic damper ring so that you can reference this TDC position again later. Either use a yellow crayon like they use in the service department of a tire store or a piece of tape placed at that position or whatever your mind can come up with. Make the mark at the top of the harmonic damper inertia ring. We are going to refer to this position as NORTH, because if you got down on your knees and looked at the harmonic damper from straight on, like you were looking straight through the centerline of the crank, this would be the NORTH position.

Loosen both adjusting nuts on both rockers on #1 cylinder until the rockers are loose on the studs. Have your friend hold his finger on the tip of one of them so that he is pinching the rocker arm down onto the tip of the valve, holding it tightly. Now, you grasp the pushrod for the rocker he is holding down and jiggle the pushrod up and down while using a socket wrench to slowly tighten down the rocker arm adjusting nut until all the slack is removed and you cannot move the pushrod up or down any longer. Be delicate here. This is not a strong-armed operation. You are simply taking all the slack out of the pushrod and getting the rocker adjusting nut very slightly tightened down against the trunnion of the rocker arm. Now, make 1/8 turn more on the adjusting nut.....1/8 turn.....45 degrees......OK, that valve is done. Now, move over to the other valve on #1 cylinder and repeat the operation.

You may have heard that you can rotate the pushrod with your thumb and forefinger until the pushrod gets tight and use that for adjusting the valves. While that may work for someone who builds motors day in and day out for a living, it WILL NOT WORK for someone like you who has no way of knowing how much resistance he should be feeling for. Jiggling the pushrod up and down is BULLETPROOF and can be done successfully by even a first-time builder.

Now, you have both valves adjusted on #1 cylinder. With the socket and ratchet on the harmonic damper retaining bolt head at the crank, turn the crankshaft 1/4 turn clockwise. That will mean that the mark you made on the damper ring will move clockwise from NORTH to EAST.....STOP. Make another mark on the damper ring at the straight-up position. Now, you will have a mark at EAST and a mark at NORTH.

You have moved the crank 90 degrees and into the next cylinder's firing range. There are 720 degrees in a full cycle to fire all 8 cylinders, so turning the crank 90 degrees at a time will allow us to adjust the valves on all 8 cylinders with just 2 full turns of the crank. If you knew that a small block Chevy's firing order is 1-8-4-3-6-5-7-2, then you would know that it is now #8 cylinder's turn to fire. Go to #8 and loosen both adjusting nuts, just like you did on #1. Have your buddy hold the rocker down against the valve stem while you jiggle the pushrod up and down to remove all play, all the while slowly turning the adjusting nut to remove the play. When all the play is removed, tighten the nut another 1/8 turn. Move on to the other valve on #8 and do the same.

Now, you have adjusted the valves on cylinders 1 and 8. Put the socket on the crank nut and turn the crank 1/4 turn to the right (clockwise, just like before). Place a mark at the top of the inertia ring like you did last time. This mark will be at NORTH. The mark you had at EAST will move to SOUTH and the one you had at NORTH will move to EAST. Following the firing order, we will now go to cylinder #4 and adjust both valves. Then we will move the crank 1/4 turn and make another mark and do cylinder #3. Then we will move another 1/4 turn (the crank has marks for each 1/4 turn now) and do cylinder #6. Then we will move the crank another 1/4 turn and do cylinder #5. Then we will move the crank another 1/4 turn and do cylinder #7. Then we will turn the crank another 1/4 turn and do cylinder #2. Then we will turn the crank another 1/4 turn and be back to firing on #1, where we will stab the distributor into the motor and install the retaining clamp and bolt. We will leave it a little loose so we can rotate the distributor housing. You may have to use a long screwdriver to line up the slot in the distributor driveshaft as you look down into the hole where the distributor goes.

As if we were standing on the motor and looking down on it, we will want to point the rotor tab at #1 cylinder, approximately 5:30 O'Clock if you look at a clock face. The rotor will move as you drop the distributor into position, because of the way the gears are cut. Pull the distributor out and rotate the rotor at another position to get the rotor to point at #1 cylinder when you drop it in. Position the distributor housing so that you can twist it both ways without the vacuum advance can hitting on the intake manifold or firewall of the car. Replace valve covers. Replace spark plugs. Using your longest spark plug wire, plug it into the 5:30 position on the cap, coinciding with the tab on the rotor at 5:30 and run the other end of the wire to #1 spark plug. The longest wires will be for #1 and #2. The next longest wires will be for #3 and #4. Next longest for #5 and #6. The shortest wires will be for #7 and #8. Going around the cap in a clockwise manner, the next hole in the cap will take the wire for #8 spark plug, then #4, then #3, then #6, then #5, then #7, then #2.

Now, depending on where the timing tab is on your motor (there were 3 different positions used), you might have to rotate the distributor housing a little one way or the other to get the motor to fire off, but unless I miss my guess, SHE WILL FIRE OFF. Have a timing light affixed to the #1 spark plug wire, adjust timing and lock the distributor down.

A little more info about the different timing positions. Like I said, there are 3 different ones. There is a 12:00 Noon position, a 2:00 O'Clock position and a 2:30 O'Clock position. Through the years, the timing tabs and front covers get mixed up on these motors, so you really should find top dead center and use the proper mark on your harmonic damper to line up with the timing tab on your front cover.
If you can follow these instructions, the valves will be adjusted properly and the motor will be ignition timed.

Decided to go ahead and run a DynoSim before going to bed.
RPM HP TQ
1500 103 360
2000 148 390
2500 185 395
3000 235 411
3500 285 430
4000 325 426
4500 353 412
5000 365 381
5500 321 306
Peak volumetric efficiency 87.7% @4000
Peak BMEP 181.2 @3500
This is a street motor, not a race motor. It exhibits excellent torque right off idle to pull a heavy vehicle off the mark smartly using the stock torque converter and tall rear gear and will do it on junk pump gas. If you are using a 3.89 gear and a 2200 stall converter, this motor should rip your head off in 1st gear, that is if you can hook it up!:eek:

Tech,
I am amazed at the effort you show to people you dont even know. YOu must have spent 8 hours on these post. I am not even building a sbc and yet I copied these posts and saved them as a separate document. Whether this person uses your advice or not, I want to thank you for the excellent post.
Many thanks!

TechInspector has a lot of good advice. If you decide against a roller cam, just make sure you add the appropriate zinc additives (EOS or other such products) to your oil and break it in properly. New oil formulations are not good for flat tappet cams. And IMO, the XE-274 is a little big for a 350 if you want to have a street-friendly driver.

Tech is very knowledgeable on this subject. I built a 383 based on his recipe and it screams. I used the comp hyd roller 286 magnum(230/230 @ .050)
I have built many engines and one thing that I have discovered is that from the very beginning, you must really think long and hard about what really you intend for the car. Are you really going to put 10,000miles on it? does it have ac and other power accessories?
As far as sound is concerned, I agree with tech. Hyd (flat tappet or roller) will never sound like the solid roller that I just put in a recent 427 ford build( 254@ .050) NEVER.
It is not necessarily the camshaft itself that is the culpit for poor driveability (aside from low vacuum) It's the things that complement the camshaft requirements ie...high compression, high stall, lowgears ect...
Comp created those thumper cams specifically for sound. I have put them on the desktop dyno and they inferior to other cams from a performance stand point.
I probably will never install another flat tappet again. After the last wipeout, too $$$
I like the sound of solid rollers as you can hear the valvetrain components clearly. Plus, solid rollers separate the fairweather corvette dorks from real muscle car enthusiasts!!!!!

WOW again techinspector1 !

I can't say enough how much I appreciate this information you gave me and the time you've taken to put this info together for me.

You've sold me on the hyd. roller set up. With my luck I'll screw something up and wipe out a cam/lifter then start kicking myself. I don't want to pull the engine and all the crap that goes with it to re-do what I tried so hard not to screw up.

I'm going to study, make notes and search all the part numbers you gave me, (I really appreciate the links and part numbers).

Again you clarified so much for me and I can't express enough for the time you took to help a complete stranger.

I will keep this thread so I can refer to it often, and of course the other members that have also posted. I value all your opinions. You guys have seen a hell of alot more then I'll ever get to experience and thats your experience I must learn from.

Like they say- "You get what you pay for, You pay for what you get"

Sincerely thanks.

Hi Guys,

Found these two cams, I will give you the numbers. This is what is hard for me to understand, so with the info earlier in this thread of my engine, car combo,
basically-
355, hyper pistons(d-cup), 9.0:1 comp., 3500 lb. car, 3.89:1 gears, 2200 stall.
Other info in above posts, don't want to repeat too much.

These two roller hyd.cams:

#1-dur@.050 234/238 - adv. dur. 296/300 - 112 lobe sep. .539 int/.548 exh.

#2-dur@.050 226/234 - adv. dur. 258/256 - 110 lobe sep. .525 int/.532 exh.

With these specs what can I expect with these cams for a street engine, manners, sound, one hve more torque or hp than the other?

Don't even know if this is a fair question.

Thanks if anyone can help.:o

I have a question about the valve adjustment. Techinspector1, you said to adjust the rocker arms 1/8 turn after all the slack is removed from the valvetrain(zero lash). I have always adjususted 1/2 turn except when using Competition Cams Pro Magnumroller lifters. The Pro Magnum is basicaly a race lifter. The rest of the Comp Cam line is 1/2 turn after zero lash. G.M. recommends :eek:3/4 to 1 turn after zero lash. I'm just a little concerned why you would say to adjust the valves 1/8 turn without knowing which lifters are going into the engine.

Quote:

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Originally Posted by techinspector1

Loosen both adjusting nuts on both rockers on #1 cylinder until the rockers are loose on the studs. Have your friend hold his finger on the tip of one of them so that he is pinching the rocker arm down onto the tip of the valve, holding it tightly. Now, you grasp the pushrod for the rocker he is holding down and jiggle the pushrod up and down while using a socket wrench to slowly tighten down the rocker arm adjusting nut until all the slack is removed and you cannot move the pushrod up or down any longer. Be delicate here. This is not a strong-armed operation. You are simply taking all the slack out of the pushrod and getting the rocker adjusting nut very slightly tightened down against the trunnion of the rocker arm. Now, make 1/8 turn more on the adjusting nut.....1/8 turn.....45 degrees......OK, that valve is done. Now, move over to the other valve on #1 cylinder and repeat the operation.
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It was brought to my attention on another forum that there are some lifters that want only 1/8 turn. This is only the static adjustment anyway, just to get you in the ballpark to crank the motor and for the cam run-in. You are expected to do a hot lash after break-in and can set the preload anywhere you think is right. I have read lately that some fellows are using 1 1/2 turns after the slack is removed.

Wow 1 1/2 turns. Maybe they should just use a solid lifter cam. Thanks for clearing that up.

Cam #2 is the better choice but I would want a little more stall--at least 2400. Cam #1 is a little larger than you want with 9:1 compression. That cam would want at least 10:1 static compression to take advantage of the additional duration. In addition, you would need more stall, more in the area of 2800-3000. I think you would like the street manners better with cam #2. Cam #1 would be a better choice for a 383 or 400.

Thanks Lynn

Cam -1 was used in 383 build with a 10:1 compression (Edelbrock 2201)
Cam -2 was recommended to me by Howard Cams, gave them by combo info and is sending it out.

I just find it hard to look at these numbers and be able to read what application it would fit, you apparently had no problem.

Thanks!

It just like anything else--the more you study this stuff, the more you learn about it, and the more you can pass on to others. I suppose it has something to do with all the years I spent teaching.

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