Need suggestions on a cam for my motor...motor specs inside...

[FJM568]

Found out that my #3 exh lobe has decided it would rather be round than have a bump on it...This cam was a Modern Musclecar 208/208 flat tappet...Need some opinions on a replacement...

Setup is as follows...TA51 turbo w/PTE exh housing, 50# injs, Joe L street and race chips, TH 3" DP, David Chase's Stage Jr heads(8445 heads that have had CNC bowl work, no exh crossover or egr provisions at all in the heads(solid)), CAS V2 FM IC, 2800 stall Neil Chance 12" LU converter(from Jimmy's Trans), Walbro 307 with an adj. fpr, steel center mains, +.030 TRW forged pistons, 109 block, and probably some other stuff that I'm forgetting...This is the motor that is in my 85 GN...The turbo is in the stock 85 location, with the custom TH DP, and an 87 lower intake with my own design custom upper plenum to make it work...I got 13k miles out of it, but lost the lobe back in Nov??? Dyno'd in mid Sept at 330 hp and 440 ft/lbs with the lobe probably already half gone on 16-17# of boost on 92 oct pump gas...Car has been parked since the ticking started in Nov...

Any suggestions on what cam to go with...can't be a billet roller, can't afford it right now...BUT I ONLY WANT TO DO THIS ONCE!!!! I may end up going with a bigger turbo and higher stall converter later, so keep that in mind, too...

Anyone have any experience with the GS club cams??? They claim NO reported wiped cam lobes ever...

Suggestions or questions are welcome...

Thanks...

 

[Lee Thompson]

club cam!!!!!

Club cam--- no lobes gone---BULL---Gone, but maybe not reported, doubt that also. I had 2 club cams to go bad a few years ago. IMO, It would be fruitless to report it. After losing those 2 plus some others, this is how I found to make a flat tappet live for an extended period of time. DO NOT go over 90 psi closed valve spring pressure, send your cam to Calico coating in N.C. Have it moly coated. Not that expensive--$40. Be sure to do a proper prelube and break in. The last flat tappet I had has now lasted 4 years. The best cam I ever used is ESP 208-224

 

[86brick]

206/206 billet roller cam is the best for your combo if you don't want to worry about your cam taking a sh!t. It will cost more than your flat tappet, but IMO it's well worth it cause you'll get the best performance and durability possible.

 

[FJM568]

Thanks Lee, that's what I was figuring...Just wanted to see what others experiences with them were...I will probably do what you suggested and have whatever cam I end up going with moly coated...Thanks for your input...

86brick
I can't go billet roller...currently unemployed on furlough...should be called back to work(hopefully soon), but just can't afford a billet roller right now...



I have a feeling that the reason I lost the lobe was when first trying to start the motor, it wouldn't fire due to crank sensor problem...Think I cranked on it and cranked on it too much and lost the lube that was on the lobes before I finally got it running...

Thanks and keep the suggestions coming...

 

[REDS HOT AIR]

i have to toss in the 204-214 cam..it will spool that 51 really good it did mine makes mad topend pull.

but beware of the 51 when you get into a cam like that
while your down go see my pics and details on were to look on you ext wheel for cracks.
as for the cam mine is speed-pro and sealed power lifters in both my turbo motors and no problems with either one.

im putting one in another GN now for somebody else.

 

[FJM568]

Thanks for the info, Reds...

I have been following the 'Tales of the -51' saga and was planning on looking mine over as soon as I get to tearing into the motor for the cam change...Just need to decide on a cam...

 

[6PacktoGo]

Get a custom ground cam

Call one of the three companies that do my custom cams, Crower (ask for Dave), Iskenderian (ask for Richard), or Reed. From my past experience they'll tell you you need around 214 degrees at 0.050" tappet lift on the intake, with about 0.470" lift, and about 210 degrees at 0.050" tappet lift on the exhaust, with around 0.450" lift. They'll want to grind it on a 112 or 114 lobe seperation angle.

Lee is correct, watch your spring pressure, and having the cam coated works. I actually have a special set of springs to break cams in, they only have about 65 pounds of seat pressure, but most people won't change springs like I do. One problem with cam life is that people want to set a Buick up with the same pressure as a Chevrolet, around 110 or 120 pounds on the seat. It will not live. Crower also has a set of lifters that has a flat on one side to oil the lobes, but you need to be able to flow enough oil to use them. Meaning a properly modified block and a high volume high pressure pump. We've also found that synthetic oil really helps cam life. We use Mobil One 15W50.

 

[FJM568]

Could you post the part # for the Crower lifters??? I do have the Hi-Vol front cover with radius'd passages(from the Buick PowerSource book) and the biggie filter upgrade(PF24)...I've got plenty of oiling and between .0015-.0020 on the rods and mains...My oil pressure is excellent...

Since the car is a modified 85 setup, pulling valve covers to swap springs is "almost" not an option...I don't remember which springs I have(980 or 981), but they do have some miles on them and the heads were assembled for a while before I got the motor running...Don't know if that will help anything or hurt...hmmm, I may just have to swap springs though...I do have a set of stockers with about 95k hard miles on them I could put on for the break-in...Would be a pita though...

Thanks for the recommendations...

 

[lazaris]

Alan,

Better than that in my opinion is the mod Crower makes to the face of the lifter. They drill a hole in the face that rides on the lobe and pressure feeds it. Since its always incontact with cam there is little if any hyd bleed and no pessure loss. I recomend it to anyone using a flat tappet cam in these cars. I believe it just about eliminate wiped cams on these cars.

 

[87LtdT]

I'd be concerned if your springs were CC981's...their spring rate is 38% higher than the 980...and the spring load at 1.25" is 29% higher than the 980's. A big deal to cam life...heack even at 1.70" they are 16% higher....that's a constant 16 to 29% extra load on the lifter-lobe joint...sure won't make the cam lobe last longer.

980's and 981's are not even close to being the same spring...be careful here.

Bob

 

[REDS HOT AIR]

none of them oiling mods are nessasary if the cam is broke in correcty.

in a hp application you dont want no more oil than nessasary dropping on any roating part

 

[QuickWrench]

Many, many of us here in Ohio have had awesome luck over the last 6 - 8 years with the classic Lunati 200-200 unit. It was designed about 8 years ago in a joint effort between an engineer at Lunati and Red Armstrong. This was HANDS-DOWN the most popular hydraulic camshaft to have for years, until roller units really caught on.

This camshaft works perfectly in combinations form 12.50 - 10.80, and has been as fast as 10.55. No detectible difference in idle quality from a bone-stock unit, and makes power through 5500 RPM. Also works wonderfully with stock - 3500 RPM converters.

This cam is around $225 with a new set of lifters, and works just fine with stock-style pushrods and timing set.

Good luck.

 

[FJM568]

I understand the principle behind what your saying there, Reds, but if I was a factory sponsored race team trying to squeak out every last hp out of my combo for that extra tenth or even hundreth of a second in the quarter, I would probably care more...But right now, I wouldn't care in the least bit if I lost 10 hp due to excessive oil dripping on a rotating assembly, much like the situation with the -51 turbo's, I just want my camshaft to survive troublefree...So, IMO, the oil splash thing is moot...

Now, the mod with the bleed hole in the face of the lifter is interesting...Are you positive it is Crower that does it or is it someone else???

Bob, the reason for running the 981's is, originally, the heads were going to go on my other motor that used to be in the car which had the KB 1txb cam kit in it, which they recommend a spring with seat pressure of 104#(which was on that motor, came with the cam kit), which is why I went with the 981(I'm almost positive that is the spring that I have on there)...Now that KB cam had 30000 miles on it before I popped the head gasket(builder put the NA head gasket on it) and the motor had a NA crank in it, so I built a new motor for it with all the correct turbo specific parts and put the Stage Jr heads with the 981's on the new shortblock that I built...I now have 13000 miles on this new motor, the heads were assembled for about a year before I installed them on the motor and got it running...

I might just try out the lifters with the bleed hole in the face...still thinking about it...I may have to check out the stock cam that is in my 87 T and see if it is still intact(motor has 2 melted pistons, bought it that way)...If it's still good, I may just toss that in my 85 GN motor and run it with some stock spec springs...

Thanks for the suggestions...

 

[JRGN]

Originally posted by lazaris
Alan,

Better than that in my opinion is the mod Crower makes to the face of the lifter. They drill a hole in the face that rides on the lobe and pressure feeds it. Since its always incontact with cam there is little if any hyd bleed and no pessure loss. I recomend it to anyone using a flat tappet cam in these cars. I believe it just about eliminate wiped cams on these cars.

Any luck on finding the part # for the lifters you talk about. Jr.

 

[FJM568]

Decided to go with the Comp 206/206 from Jack Cotton...

Thanks to all who have replied...

 

[1badTTA]

Time to bring this one back to the top since I am in the same boat. I was running a GN110T camshaft from postons and wiped the #1 exhaust lobe. I had the high rev lifters from postons and springs from Jack Cottons that are 110# @ 1.800. I always had a slight tap at startup until I got oil pressure and then on wednesday I got a loud enough tap to send the knock sensor crazy. Got the car home, pulled valve covers and noticed a bent pushrod on #1 intake, replaced it and started it up again. The exhaust valve barely moved. Pulled the intake and ex lifter, had a .100" cup to it and the cam had almost no lobe.

This is all within 4500 miles of a rebuild with new cam, lifters and springs. The cam was broke in for 25-30 minutes @2500-3000 RPM and the oil changed after then again 500 miles later.

Need opinions on what caused this and wheather my stock cam can go back in with new lifters and survive. (stock cam has 36K on it and looked great when pulled)

PS, Postons is willing to warranty the cam and lifters, but if it was the springs that caused it I think Cottons should cover it since they swear up and down that they have had no problems with those spring pressures.