Hey guys: Looked through the stickies and did a search: anything that comes up for towing/rv cam is at least 4 years old. Even then, no real info. Looking for the best cam for a 350-2, 9:1 compression, going into a 3500lb Jeepster Commando. Will be used for offroading / towing. 32" tires, 4:11 gears and a 1:1 final drive ratio net me 70mph at 3000 rpm on freeway... So... I'm looking for a torque cam that will deliver between idle and 3500, and give me decent efficiency on the road. 262H is advertised as a good towing cam, but that's why I'm asking y'all.
The ta rv112 makes decent power for towing in a car with 2.73 gears but with the deeper 4.10 I would say the ta 212. With ported heads and big valves this cam has made 350 HP/400lbs in several engines on lower compression.
Crower level 2: Valve timing events: @.006 lift IVO is 22.0 BTDC ( - indicates ATDC) IVC is 58.0 ABDC EVO is 69.0 BBDC EVC is 17.0 ATDC ( - indicates BTDC) Overlap is 39 @.050 lift IVO is -7.0 BTDC ( - indicates ATDC) IVC is 29.0 ABDC EVO is 41.0 BBDC EVC is -11.0 ATDC ( - indicates BTDC) Overlap is -18 .280.281 lobe lift .434/436 valve lift @ 1.55 stock rocker ratio 202*/210* I/E duration @.050 260*/266* I/E duration @.006 112* LSA @4* advance install 108*/116* I/E centerlines SCR @ 8:1 DCR: 9.53:1 Website: http://www.crower.com/index.php/camshafts/buick-350-compu-pro-hydraulic-cam-260-hdp.html For an otherwise stock 350-2v with 9:1 advertised compression, this is your cam. With a powerband firmly within 1500-4000 RPM range and (for racing) shift points between 4500-4700 RPM (for a 4v setup), this cam should idle even smoother than the stock cam at an even lower RPM, with more vacuum. With a 2v setup, torque will come on sooner but power will begin to trail off more quickly, with a shift point (for racing) at around 4300-4500 RPM, depending on size of 2v carb. (guestimation) With early intake valve closing points makes for better compression stroke and more efficient use of the smaller intake charge, while exhaust evacuation is extended for a thorough combustion cycle and effective low-RPM efficiency. "Compression" could be between 8:1 and 9.5:1 for use with regular up to premium pump fuel, depending on compression. Remaining valvetrain can remain stock. Cam should produce some impressive low-mid range torque with a 2v setup. Gary
The lowest rpm off the shelf grunt cam is the Isky Mile-A Mor http://www.iskycams.com/Wc900150ef8c44.htm If you are talking about slow off road "in the rough" type of driving then this is the one. If by off road you mean faster fire road type drivig then Gary's suggestion Crower level 2 might be better. What transmission are you going to use? Paul
Crower level 2. Also will provide better mileage. Is that Isky really 108 lobe center??? FYI Crower level 1 was discontinued last year. They were blowing them out for like $25.
Yeah it is, Steve. Seems it's more of a specialized, focus type cam with little variance in usage. Which is cool if that's what you want. I checked out Isky's catalog and was left with a big soft rubbery one. Didn't really tickle my fancy, but hey different strokes for different folks. All cams seem to be 100% straight pattern with 108-112 lobe centers. Doesn't take much thought or creativity to pick or design one of those cams. lol Just my 2c. On the Crower level 1, I figured it was something like that. I wonder if they're going to replace them with another type of grind? Gary
Yes. The Isky cam has a 108 lobe center but keep in mind the it also has 4 degrees less overlap than the Crower cam. If you were basing fuel economy on overlap then the Isky wins. The intake valve also closes 4 degrees sooner than the Crower. For that short of duration it has a relatively high lift. It is an all around better cam for low rpm high torque applications. Paul
While that Isky cam is probably better for idling over big rocks with a 3000 RPM redline, the combustion cycle isn't as well suited for a better overall usage cam. With the straight pattern design and super tight LSA the engine would fall on its face after its peak torque and would be better suited for a tractor with a governor to regulate its max RPM. Exhaust evacuation would also be hindered, but probably wouldn't matter as much on a cam so small coupled with a 2v carb. Gas mileage is determined by more than just IVC points and overlap. The Crower level 2 already has a 39 degree overlap which is pretty tiny compared to the stock cam's 53*. Much less than that and it probably won't make that big of a difference because the engine will only idle so slow. Enhanced exhaust evacuation will help with fuel economy because it helps to offset the combustion contamination on the intake cycle, which equates to more efficient use of the intake charge. This also has its limits, and as said before, may not make that big of a difference with such a small cam and carb. While I'm not saying it's a poor choice, it would be best suited for a more specialized application for strict off-road use. :TU: That's my story and I'ma stickin to it. (It's awesome to see your point of view though Paul. Your knowledge and opinion here are highly respected and appreciated) Gary
I'm not disagreeing but we can't comment much further until we hear from Magilla2 on if he is rock climbing or cruising. If he is serious about not running the engine past 3000 rpm then it doesn't matter much about exhaust emphasis. You'll notice I also asked about the type of transmission that will be used. You'll never guess where I might be going with that. Paul
Ja wohl, Herr Muller. :TU: If I had to hazard a guess, I'd say it had something to do with ratio variances. More gears = less variance between each gear = engine doesn't need to have as wide of a power band. Am I close? Gary Yep yep. :TU:
For the sake of fairness, I must say I'm partial to the Crower cam, so I admittedly have a bias. Second, if the 2g carb was the small base, I would lean more toward the Isky cam. Since it is highly likely it's the large base, it could go either way for either cam, though I would lean more toward the Crower level 2 the larger the CFM went on the large base version (there's a few different CFM variants). So there's my objective opinion. Gary ---------- Post added at 05:48 PM ---------- Previous post was at 05:47 PM ---------- Well I was close. My thinking is backwards sometimes anyway. We'll see what he has to say about which trans and which usage he plans on.
I say stick with a stock cam and spend your money on off road goodies(Tires, Lights, Winch, ect.) When off-road you want RELIABLE predictable power across the board. The stock cam does this pretty well.
I missed that a M465 tranny with Dana 20 tranfer case was going to be used. Furthermore after doing a little research the 5 speeds like the NV4500 need adapters and the drive train gets too long for the Jeep making a real bad driveshaft angle. Never Mind! Paul
Stock works too. Cheaper, and it comes with the master rebuild kit along with the proper timing gear/chain which you just bolt right up, no fussing over indexing errors, etc. Here's the stock specs for analysis: @.006 IVO is 19.0 BTDC ( - indicates ATDC) IVC is 71.0 ABDC EVO is 79.0 BBDC EVC is 34.0 ATDC ( - indicates BTDC) Overlap is 53 @.050 IVO is -15.0 BTDC ( - indicates ATDC) IVC is 24.0 ABDC EVO is 40.0 BBDC EVC is -12.0 ATDC ( - indicates BTDC) Overlap is -27 Stock cam has asymmetrical lobes, so the timing is all over the place depending on the lift of the lobes. Speed Pro's Stock Buick 350 camshaft: .243/.253 I/E lobe lift .377/.392 I/E valve lift @ 1.55 stock rocker ratio 270*/293* duration @.006 189*/208* duration @.050 112.75* LSA @.050 109.5*/116* I/E centerlines @.050 114.25* LSA @.006 116*/112.5* I/E centerlines @.006 This equates to a 1.75* retard setting @.006 and 3.25* advance @.050 Can anyone see why this camshaft confused me earlier on when I was trying to learn camshaft basics using this as my learning foundation? lol Gary
with the 4.10s and 32 in tires i was thinking that he will need to have some power past 3000 atleast to 4000. and i believe the original cam would be better then a stock replacement that would be more similar to the 80 version than the 72 version in his motor now. i would think getting his compression up to 9.0 or close will increase the low end he wants for his purpose.those 2 barrel carbs are about 500 cfm which again will work better for his purpose since he doesnt need alot of rpm and needs to keep torque up thru the power band . "the carb shop" does these carbs up to 600 cfm. another thing to consider is exhaust as too much flow could ruin some low end
I've not used the Isky but the numbers look stone age. Maybe OK for a tow truck. My mileage claim is from having used the Crower levels 2 and 3 in different engines. They make big block torque with mileage as a bonus.
when you pull heads see if you have a steel shim head gasket. not really available anymore. they are .020 thick. most replacements(like fel pro) are at least .040 thick . so your compression will drop . you could easilly shave .030 off heads to get that back and not have any problems. i do have a set of standard 70 Hi compression pistons and rod for sale if interested.
Outstanding! You guys are a wealth of knowledge. Currently running a 231 even fire with a T14 3-speed and Dana 20. Buick 350 will be mated to an SM 465 and Dana 20. SM 465 has 6.55 granny low 1st, then the gears almost match what I have in the T14: 3.58, 1.7, and finally 1.0. Dana 20 low range is 2:1. 4.10 gears in the Dana 44 and Dana 30. My rig is dual use. It tracks straight with 2 fingers on the highway at 75mph (I installed YJ Wrangler leaf springs, Saginaw close ratio power steering, and all new front axle hardware - balljoints, tie rod ends, etc.). I get a LOT of looks in the old Jeep passing folks in the left lane on the highway... Offroad, it is used primarily on fire trails, but with the 6.55 granny low and transfer case, I'm looking at the capability of a crawl ratio of about 54:1. In other words, idleing at 800-1000 would get me about 1 mph... With all that being said, the intent is to create an all-around vehicle, with reliability, efficiency, and torque the driving concerns. Hoping to get away with a hone and re-ring, rebuild of oil pump, and HEI on the 350-2V. Will do a master rebuild if required. So, I guess I'm looking at a stock or a crower 2 cam. Thanks for the replies. I have some good experience tuning the 231 HEI - I'm running 35 total mechanical advance, and am running manifold vacuum to the distributor. Initial is set about 14, plus 21 mechanical advance - all in by 2500 with two light springs, and vacuum limited to about 11-12 degrees. Off-idle response is great, as wella s mileage. Hoping to replicate that on the Buick V8, with more torque!
