Ok heres what i have. Barry grant 1000 cfm carb with 82/88 jets 4.5 power valve up front and rear blocked off. Accelerator pumps are 30 front and 50 rear with 37 squirters and is setting on a KB cool runner intake with a 1 inch spacer. 69 430 heads with full race port and stage 1 valves and combust chambers worked. T/A 1.65 roller rockers and push rods. T/A headers 2 inch primary and 3 1/2 inch collectors with 3 inch exhaust thru dyno max mufflers out the back. Block is decked at 20 and bored 38 over with BME flat top 12.5 to 1 pistons. But 13 to 1 with head combo. Using stock rods and crank. Crank has been cross drilled. Heads and mains are studded and cam is a KB 107/118 and a KB oil pump kit. Stock pan with 5/8 pick up tube and using pennzoil 15/40 long life oil. Ignition system is MSD 6 AL with HEI distrib with timing set in at 32 degree all in at 2500 rpm. Transmission is turbo 400 BB code with shift kit and race pack with harden sprag and a 3200 coan stall converter and using the a/c core as a trans cooler. Rear is GM 8.5 big 10 with a posi 390 gear ratio. Rear tire size is 27x10.1/2 hoosier quick time pros and fronts are 26. Car is a 1970 buick GS stage 1. Car weight is 4100lbs with me. Suspension is 90/10 front and 50/50 rear with air bags and 15 psi in pass side. Best ET 11.87 at 113 mph. 60 ft 1.63. 1/8 mile 7.31 at 91 mph. on hot days 12.0 to teens. Ok with all that said my motor blew a head gasket on drivers side. Motor was built back in 95 and had about 8000 miles of street and strip time. So now its time to freshen it up. If i change the cam to a sp-4 with 253/ 266 will it run better than it already is. Thats about the only thing i am thinking of changing on the motor. The BME pistons look like new with no scuffing and cylinder walls are very clean. Also i turn the motor up to 5700 rpm from first to second and third and pull thru the traps at 5900 to 6000 rpm. I ask you buick experts will this cam change help any or is there a better one for this set up. I am looking to go faster of course" Thanks very much from Billy in sandston Va. :TU:
Why go with a hydraulic cam? Put a 308 solid in it or something compairable to match your combination. I would at least put something with 260+ degrees on the intake on 108-110LC. With 13.0 comp you need to run a big cam or cylinder pressure gets out of control. And basically anything bigger than what you had would run better. I'd put the 50cc pump on the front of the carb. It will help the carb repond faster. It looks like you jetted the carb down from stock.
The SP-4 253-266 is an old camshaft(late '80's early '90's) it's not being made anymore(as far as I know). Rick is correct about cylinder pressure getting out of control. I have a combo close to what you are running. SP-4 camshaft(253-266) 12.5:1 compression, Stage 2 street eliminator heads. My cranking compression is way to high(over 250) I have blown 3 sets of head gaskets with this combo. Also as Rick said a cam with 260+ intake duration would be better suited for your combo. I have a cam with 262* intake duration this should alleviate my head gasket problem.
What would be the best hydraulic cam for this combo. Because i do drive it on the street some but mostly race it. And i was also thinking about going with a roller cam any thoughts.o No:
I would say go with a TA performance TA608 hydraulic. If you want a hydrualic roller I will have to get back with you . I need to contact the person to see if he is still doing them. When you go to this cam or something similar, you will have to put a little more timing in it @34 and go up on your jetting a little. If I could talk you into a solid it would be a TA294-98F. 260/266 @ .050. You really don't need as much spread between intake and exhaust since you have 13.0 comp which reduces to the exhaust requirement and you need to keep your rpms down running the stock rods with that comp. and the fact your pushing 4100lbs. This solid would be the best choice and still can be driven on the street. But if you insist on a hydraulic, so be it. You need to check your guide clearance to retainer on your heads while your motor is apart to check how much lift they will handle. You don't want to get a cam in a motor thats assembled and realize the heads won't handle the lift.
Billy, That 260/266 solid from TA is a really nice cam. I have it in my S/S 65 Skylark and love it. Good luck!
I've set up a couple of Mustangs with decent sized solids that run on the street. I've checked them after 1000+ miles and never had to re-adjust them. Once you get used to the engine noice you'll hear if they get out of adjustment. at least I usually can, especially on a car with exhaust. It doesn't happen all that often. I heard it more on high mileage Honda's civics than anything.
I have run this cam for the past year and the valve lash was almost dead on last month. I do have TAs roller rockers which I would image help.
I know this cam is old but a couple people tell me it works good. Its a poston GS- 105A with 105 L/C and 302 intake / 310 exhaust duration with 520/523 lift. They say it will really wake the car up for my above mentioned combo.o No: So what do you guys think of this cam set up? They claim it is an easy 11 second cam? Let me know the pros and cons on this one. Thanks Billy.:laugh:
The lobe center are a little too close and it doesn't quite have the duration you need. What saved you on your other cam was the 118 LC's. The 105 cam has an awsome sound to it from the large amount of overlap. Very Choppy. I've heard of it working well in heavy car with 11.0 comp but 13.0 is too much. Lobe seperation of only a few degrees my not seem like much but the difference in overlap of two identical cams, one with 105 and one with 108 is actually 6 degrees. The 105 cam intake valve event at.050 closes 10 degrees sooner than your 107/118 cam. Which equals too much cylinder pressure. Even though it has more duration on the intake. If you really want a hydraulic cam, try TA 608B. Its designed for stage two heads, but It will work good for your combination. Even though it doesn't have the duration split iron heads usually run, with your combination it fits. The higher compression you run and the lower you limit your rpms the less exhaust duration is required. So either the solid or hydraulic should work best. Other than those two off the shelf cams, I would have one custom ground through Comp Cams, Lunati, Crower, or Crane. I would offer a recommendation off other cams offered such as through Poston but they don't list the specs on there cams on line.
Hi Guys, Rick....actually Charlie Evans has made a pretty complete BBB cam chart (everything BUT ADVERTISED DURATION) from all the various manufactures. Many, that he has access to the cam cards, have complete detailed spec's. He will also add whatever he does not have if our fellow Buick Brothers who might happen to have their cam cards to help him fill in the ones that are incomplete. The website is: http://chicagolandbuick.org/partners/Charlie Evans cam tables.htm Anyone how has one they are willing to share can send them to Mike Phillips @ ampmike@aol.com and I'm sure he will forward to Charlie to update with. Hope this helps...
Billy, With 12.5:1 compression on a 464 BBB you should have nothing smaller than 263 degrees of duration at .050 on the intake side with a 108 LCA and degreed in at a 106 ICL. Most likely the small camshaft caused that head gasket to blow. Its stressing all of the other components also. Good Luck
Thanks Guys for all the info you supplied me on cam selection. I will use either the TA-608B or the TA-294-98F solid. I am leaning towards the solid lift so far and will let you all know how it works out in a couple of weeks from now. Once again thanks very much.....:TU:
