I don't know, after calling me Steve I don't if I want you thinking about me any more..... :laugh: Thats pretty much a "motor" cam for a Buick with iron heads which would make it real strong on low boost from 3000-4500 but causes the boost to spike up top more than it should since its starting to fight back pressure. It is still going to run strong as hell since you pushing more psi at high rpms but the cylinder pressure becomes a problem with the stock gaskets. So I'm not knocking your combination but just thought to give you an alternative to think about for in the future and little more explanation for all your fans that are following this. I don't want people to think that you need copper gaskets or high dollar gaskets just to get it to work on a street Buick. I feel these ATI ProCharger kit are awsome. I think everyone should have one. It the easiest way to get a street car in the 10's and even 9's in the1/4mi and keep good manners on the street that you could run pump gas in if you wanted to.
It's all good Steve.....urg I meen Rick :Brow: I here what your saying. The reason I've stuck with the cam is the mire fact that the heads have been setup for it (spring presure wise) as well as the the push rods..... Just for kicks, shoot me a pm of what your thinking Cam wise or post it out here in the open. It may just sway me to wait another few weeks and stab a cam in it while it's out of the car......... Keep in mind, this is a street car that has to pass emissions tests (more street than race). Looking forward to see the cam choice.
Man, this is a huge post Rich. I've been keeping up, best I could, but I can't remember if you're running a knock sensor (ruled out detonation)? I've had my share of fun with a turbo Buick and can only call on that experience. Currently, the head gaskets are definately your "pressure relief valve" for too much cylinder pressure (dynamic compression or simply detonation; either one will lift a head). Not sure where your next weakest link is going to be once the Cometics get installed (main webbing maybe??), but the Cometics will definately expose that weak link, and it might be catastrophic. If I remember, Lawrence Conley may have messed with boosting a big-block Buick way back when?? He seems to be someone that is not "tight with his knowledge" that maybe you can get some tid-bits from as well. I'm not brave enough to venture where you are, so don't take any of this as discouragement. My 2 cents are to save your expensive hard-parts by whatever time-consuming re-design it takes to lower cyl. press, ID detonation, whatever (I'm not an expert by any stretch)....I know, it sucks to have a car down during the summer driving season!!! But it will be worth it in the long haul.
I honestly think it was the increase in boost lifting my head. I had 20 1/4 runs on the motor (on a fat tune) with 5.5 to 6 psi (same pulley I got 10psi out of). I think just over time, with possibly a little stud streatch, and the 10psi was enought to push it over. I don't think detonation was the issue. The plugs have been good. and my AF at full throttle was under 12 to 1 with the alky spaying. I dare venture out on a limb to say if I had retorqued the heads a month of two ago, the gasket wouln't have blown out. On the good side, all the bearnings look good (mains, rods, and cam). It's on it's way back together, but probably won't be running until next week....... I have to take some time and clean the engine bay while it's out......... ON another side note, I'll be trying a 750 holley with a proform body to see how it responds on the car with tuning. The adjustable air bleeds should make it very nice to tune.
I would blame it all on the boost. Stock gaskets should take 10 pounds of boost just not with a small cam. Plus with a small cam it will be more sensitive with timing. Even if there is no detonation, it doesn't mean its not too much. Only a dyno or drag strip can tell you by a little test-n-tune. :TU:
drag test and blow...... Well went over to Bristol drag way last night, (Tuesday) made 4 passes. The third pass went 12.20 @ 110 mph with a 1.88 60ft time making 7 lbs. of boost. The last trip of the night proved to be the straw breaking the camels back. On the last trip down the track I went 12.38 @ 109 with a 2.00 60 ft AND blew the drives side head gasket on the second cylinder back. It blew out at the top under the intake. :af: I was lucky it blew where it did because I had to drive it back home (60 miles). I did a compression check today which showed 150 on all cylinders but one. The bad one only went up to 30. So the cometics aren't living up to my expectations! On the bright side, my turbo 350 trans. held up nicely :grin: Rich, it looks as if O ringing the block may be our only answer to finding the best head gasket.......... o No: Rick
Dang Rick that sucks!!!!!!!!!!!!!!!!!!! Do you know if the gaskets were the older 3 layer gasket, or the newer 4 layer gaskets??? I'm aslo wondering how many times the heads were torqued? Are you using Studs or bolts? I had about 20 passes at 8psi or better on my composit gasket this last time before it blew..... and I really think If I had retorqued them after the first few boost runs, they would still be living...... this is with the upgrade of studs....... I've torqued mine 4 times so far (on the stand) and plan on doing them again after I've run boost through it a couple of times (Hoping to take what little streach out of the studs that there will be. After that it will be a cross my fingers and wait. If it lasts until oct, I'll retorque them right before Vegas this time :Brow: Can you post a pick of the gasket or email it to me, I'd like to see if it looks like the headed lifted and caused the blow out. Again.... sorry to hear about your problems....... However, I'm glad it's not me for once :laugh: If I can have the gaskets hold up this time, we should have a recipe that will work :Smarty: Wouldn't that be NICE for everyone :beer
You guys are bumming me out.. AAACCCKKK.. Don't be bumming me out with stories of Cometic head gasket failures on blower motors... Got a purpose built 494 street blower motor in the final stages of prep now.. 8.5-1, 238/248 on a 114* lobe center cam, STG 2 SE alum heads, SPX, yada yada yada.. Geeze... may have to O ring the block, and go copper.. And I HATE copper for street applications.. 750 HP on pump gas? Coooouuulld be.... But need reliablity.. motor going to Michigan.. JW
Head Gasket Hey guys. My name is David and I have the Vortech YS trim supercharger on my 71 GS that has been on this site before. I don't know what the heck is going on with the head gaskets. I am still using stock felpro head gaskets without a problem and my motor was five years old before the blower was put on and the car went 126 mph before I tuned it and gained 60 lbs of torque and almost 60 hp on chassis dyno before I tore it down. I probably had 80 dragstrip passes without a problem and then tore it down to build a stage 2 headed motor for the blower to breathe through. Are you sure the machine work is OK in regards to your deck on the block? You guys are not running that much boost. Maybe I have just been lucky, I don't know.
Re: Head Gasket Your gaskets were seasoned before the blower install weren't they? I didn't start running into issues until I swaped gaskets (doing so to lower the compression). My machine work is square and good.. had them checked when it was apart last..........
Re: You guys are bumming me out.. Hey Jim, I think you will be fine with the 4 layer cometics, and some retorquing after a little dyno time........ Mine should be back on the road this weekend ready for some more R&D..... We should know in a month if things are going to be happy with the cometics and a retorque after a couple of boost runs....... I personally feel pretty good about it.
specs Hemi Killer cam on a 110 lobe center. 9.76 to 1 compression. Gessler Level 4 Heads flowing 272 at .500 on intake and 202 at .500 on exhaust. Car ran high 11s on pump gas at 114 mph prior to blower being bolted on. Blower peaked at 7.6 lbs of boost which was good for 814 lbs of torque to the wheels. Torque never went below 600 lbs of torque during dyno run. When car ran 126 it was when car was not tuned and putting down 771 in torque to wheels.
Success :beer After numorus hours (late hours) the motor and trans are back in the car! I've got it dialed in way on the safe side and it feels very GOOD.... infact good enough to leave be for now. At WOT I have an AFR of 10.8 to 10.6 to 1 (with no alky injection). The super big pulley (450) largest pulley yet is giving me 7 to 7 1/2 psi in the head (in the 90's today). Timing is set at 27 / 28 degrees (30 degree mark is below the timing mark... Now that it's seen 7 psi a couple of times, it's time for a head re-torque! I'll be doing that later today. I'm just glad to be :3gears: again! All this work makes me think someone should by me a beverage in Vegas in October :Brow: Out for now, Track times to come in the not so distant future.
update Well upon pulling the head, I got another surprise. As you can see in the pic, I've also roasted the top of the piston in the cylinder that blowed the gasket. I put a straight edge on the head I took off and shined a light under the straight edge to see if I could see any light coming threw which would tell me how flat (level) my head was. On the blowed cylinder and the one next to it going towards the back of the car I could see light coming threw!ou: So here's what I think has happened, Head warped not flat which causes head gasket to blow where it's warped. It blowed into the crank case, so now that cylinder is sucking in more air than it needs causing it to go lean. If I had of trailered it home instead of driving it home with a lean cylinder baking the piston for 60+ miles I would only be needing a head gasket BUT I didn't so now I also need a shinny new piston to go with my nice new head gasketou: As of right now, the way I feel about the whole thing is after I get this mess straightened out, my ride will never see another 1/4 mile run down the track! I'm so sick of working on it all the time, I just want to get in, drive it and enjoy it! Now I will do some of this :3gears: on the street but it wont last for a 1/4 of a mile. Well enough :rant: ..............Rick
Dang... that sucks Rick...... It looks to me like the gasket may have failed from being lean....... Did you have the wideband on it at the track???? If so, what was your AFR at WOT.. Anything over 11.5 to 1 on pump gas with more than 29 or 30 degrees of timing would be pushing things IMO............. I feel your pain as far as working on the stuff all the time, but I KNOW there has to be a happy recipe for these things to live through tons of abuse.... Heck.... mine lived thorugh 13 passes this winter in a 3 hour time. I pretty sure that If I had retorqued my heads after that trip, I wouldn't have lost the gasket this time around............................... all speculation though. Once again sorry to see the carange... give me a jinging if you have any questions.
