Invasion1 Posted August 27, 2003 Report Share Posted August 27, 2003 ' Quote Link to comment Share on other sites More sharing options...
95GTP Posted August 28, 2003 Report Share Posted August 28, 2003 I noticed "Summit" has an aftermarket cam for a 3.1, I think about $165. Not sure if it the right one needed. ==95GTP Quote Link to comment Share on other sites More sharing options...
dbtk2 Posted August 28, 2003 Report Share Posted August 28, 2003 You've got a PM! Quote Link to comment Share on other sites More sharing options...
mfewtrail Posted August 29, 2003 Report Share Posted August 29, 2003 there is someone on here w/ an aftermarket cam in a TGP engine..but his sn slips my mind at the moment...if I think of who it is, I'll let you know..or maybe in the meantime the said person will respond. EDIT: I have pictures of his TGP that he posted a while back, he has a very nicely painted engine(red and black..)..probably the only one w/ that scheme, I belive he is also the guy that moved the coil packs to the top of the motor in between the dog bones Quote Link to comment Share on other sites More sharing options...
Mike J. Posted August 29, 2003 Report Share Posted August 29, 2003 The guy with the red and black engine and who is running a Crane 25H cam is Sleepered90TGp, I believe. Here's a link to a topic he posted about the cam. http://www.w-body.com/forum/viewtopic.php?t=955&start=15 Quote Link to comment Share on other sites More sharing options...
SleeperRed90TGp Posted August 30, 2003 Report Share Posted August 30, 2003 Yea that be me, Can’t say to much about cams rite now, had some major problems. The 25h000016 was a little better than stock but after 3k miles I discovered that one lifter stopped rotating and put a groove in the lifter. Called Crane and they said they would replace it. I up graded to there 25h000018 (284/276 duration and 480/487 lift) along with there recommended springs and wiped it out in 10 minutes of running. Never got the car of the stands. It litterley destroyed the cam. 4 wiped out lobes ant the rest looked like they were going. The cam will be at Crane Wednesday for evaluation. I have put quite a few cams in engines and have never had one fail. This blows me away. Until I hear from Crane or find out what happened I wouldn’t recommend an aftermarket cam and Crane is about the best as far as I know. They blamed the first failure on synthetic oil which I put in after about 500 miles. They can’t blame that on the new came, no synthetic and it was a brand new engine. I’ll post when I get there evaluation. This cam is about the limit unless you want to notch pistons. Only had .090 clearance and the rocker arm slot is about to run out of clearance had like .055 to .060. If you get a Crane came get there lifters. There expensive but they will be covered under warranty. I didn’t because they didn’t have any when I bought the first cam. There in stock now. This cam series was designed for the Buick Grand National and has about the best numbers I could find. My cam hole sure is comming in handy. Jud Quote Link to comment Share on other sites More sharing options...
PaPaPooh Posted August 30, 2003 Report Share Posted August 30, 2003 nice to be cranes ginni pig huh? Quote Link to comment Share on other sites More sharing options...
TurboGTU Posted August 31, 2003 Report Share Posted August 31, 2003 Did you notice any coil bind. were the keepers hitting the valve guide.. Rocker ratio and type...spring pressure open/ closed? Curtis had the same prob with radical cams like the one you have. He went roller. I think .460 lift is already high for a flat lifter. .480 is already pushing it but just enough to get by for a street/strip machine on thies engines. But you had .487 on the exhaust(would be right) were those the ones that were wiped completely? If anything I think it might be the springs. I think. Quote Link to comment Share on other sites More sharing options...
TurboGTU Posted August 31, 2003 Report Share Posted August 31, 2003 I didn't see that cam you listed on their site. However I did see the cam we are all thinking is the best turbo cam (PowerMax H-260-2 [basicly stock but with the better lobe seperation...109 stock...this ones 112) and also the cam I think is best for the ones running 5spds (PowerMax H-272-2 {but has 480 ex lift}). The only bigg cam I think we could run is the first mechanical they list there. And thats pushing it...only a bigger turbo..and sterdier components and prep. BUt hey..if you want big real big...and you have the flow..BOWTIE the sucker. Quote Link to comment Share on other sites More sharing options...
SleeperRed90TGp Posted September 2, 2003 Report Share Posted September 2, 2003 Correction on the exhaust lift it’s .467 on the exhaust. Don’t feel like a guinea pig more like a stuck pig. Yea 480 is pushing it but it should work ok. I had no bind or interference anywhere. Used a made up solid lifter to check clearances. Went down an extra turn and a half (.06) and still had clearance. Both intake and exhaust were effected. I know the cards are not listed. Don’t know why. I think I’ll ask them to put them on there are at least 4 grinds. Here’s the cards. Jud Quote Link to comment Share on other sites More sharing options...
TurboGTU Posted December 16, 2003 Report Share Posted December 16, 2003 So whats the virdict on the cams with Crane Jud? I have kind of studied some more on the cams...but...im confuse on how to find out on overlap (when in and Ex are open at the same time). I notice on the last cam card its marked "Overlap 57"...is that degrees or a degree...or what? :? ...I have the 2-260-2...cam...I would think it would have a boost friendly overlap. I know it has a boost friendly lobe seperation. Some people might ask "whats with the overlap and lobe seperation?"...well...on thiese boosted engines...the exhaust presure can be so high that it surpasses the intake presure (ie...12psi intake...while the exhaust is 17+psi..{also gives you a clue why some x-overs fail}). When you have a greater exhaust presure than intake....which diretion do you think the flow of air is going when both the intake and exhaust valves open at the same time..? RIGHT...the exhaust will creap up the intake...therefor no fuel and air in the cylinder....untill the exhaust valve closes. This is verry critical in making any kind of power. On N/A engines...some overlap is great...cuz the exhaust acts like a vacume to "pull" intake air into the cylinder...but remember...we turbo freaks have verrrrrry high presure at the exhaust. So don't even bother with N/A racing cams. Also lobe seperation. Guess what? Air is forced in...(noshit Sherlock!) the cylinder...and the valve is big compared to the exhaust. So...what helps evacuate highly pressurised exhaust gasses out a small valve?....MOre timming than intake. I also read some intresting things on the 60d power manual (well from some pages I got on the net). Thise engines don't like mechanical lifters. Why? Cus of the oiling system. It states that mechanical lifters bleed off too much oil at the seat that it could cause oil starvation/low presure to the crank. Theres only one oil gallery (the left oil lifter gallery) that feed the crank oil. So be careful. It states Sealed Power AT-992 lifters are satisfactry for mechanical cams...and that Chevy mechanical lifters aren't to be used on theise engines. Quote Link to comment Share on other sites More sharing options...
TurboZ24 Posted December 16, 2003 Report Share Posted December 16, 2003 I need to actually look into a hydraulic flat tappet cam profile best suited for a turbo application. I'm soon going to help a friend repair his motor after a slight oil system failure (failed oil cooler line...) and we were thinking of adding a performance turbo cam as well as ported heads. I really didn't have problems with the flat tappet cams until I started really pushing the engine to get more power. The first failure was probably from valve float on the hydraulic lifters (over reving). The next failure was from incorrect lifters, and the next was from high boost/HP problems. I just gave up and went Mechanical roller, which lead to a lot more breathing. Given an example, my first 1/4th mile runs with a 212/206 .454/.46 flat tappet hydraulic cam was 14@91.36 mph @8-9 psi The engine now with a 254/246 .62"/.60" roller mechanical cam (also ported heads, better down pipe, and better tuned ignition) runs 110-113 trap speeds @12 psi. My pre-turbo exhaust is also causing me some severe restrictions, so that should improve more when I fix that. On that cam failure, which lobes are failing? Random? Or exhaust? Only my exhaust lobes tended to fail on the flat tappet cams. Quote Link to comment Share on other sites More sharing options...
dkorinko Posted December 16, 2003 Report Share Posted December 16, 2003 When i have time i am still looking for the cam specs on the Lunati cam i have...I know many people have asked for them and despite what u may think i am not ignoring u lol. If i cant find any paper work i will get ahold of the previous owner mike gardner (which some of u know) he seems to know just about everything! Quote Link to comment Share on other sites More sharing options...
SleeperRed90TGp Posted December 17, 2003 Report Share Posted December 17, 2003 Well Dave the new cam is in and seems to be holding up although I did some oil modification to the troubled lobe. (made sure it got oil) Also used v8 cam bearings. Only got 1k miles on it but that’s better than zero. Oil filters at this point are clean. That’s crankshaft degrees. Add intake opens (31) and exhaust close (26) that’s your overlap. Your is 42. Lobe separation add the 107 and the 117=224/2=112. That’s not a bad cam should work well. I like the intake opening atdc. I would like it better if you swapped the valve events exhaust for intake.( You said it yourself less duration and lift on the exhaust. Note Curtis’s cam and both of mine) With a turbo you want to block the exhaust unless you can get free flowing exhaust. Dream on. Wish I could take my intake profile and twist it to get the intake opening closer to tdc or atdc but then I would have so much overlap it prolly wouldn’t run. I could use less overlap. I would like around 50 to 52 max but that was the grind they had and I don’t know enough to tell them how to grind one. This cam has toooooo much low end although it did pick up 7 mph (86 to 93) with a 2.92 60’ verses a 2.2 when stock. The track surface was brand new and slicker than owl shit. :?: Thought I blew my tranny it spun so much but I was still moving so I hung in there. Needless to say my et’s were awful. Two guys almost hit the wall it was so slick. There were over 300 entrants so I only made 2 runs. It was colder than a well diggers ass and I didn’t feel like working in the 30-degree wind chill. There closed for the winter so I’ll be there in late Feb. Yea I know its colder up there but I am a California boy. You know “climate best by government test†Actually if you look close at the cam/lifter oiling system It’s a joke. :shock: Biggest problem is no spray from the crank. Then they tried to compensate by putting runners from the top of the lifter to the cam lobes. May work fine on the left bank when the oil falls on the cam and lifter before the lifter hits the ramp. Great what about the other side when the oil hits the ramp after the lifter hits the ramp and then slings it off on the way to where it needs it. OH were smart we will grind a flat on the lifter so the back side gets a little oil. Great Idea except the lifter only rotates about 25 degrees per lobe lift so it takes awhile for that oil to get back around to the cam. Great engineering. One more thing on oiling. With your new cam, Don’t reve the shit out of it caus it doesn’t Make any difference as long as you have plenty of oil pressure. There’s no spray from the crank which crane hasn’t notified anybody of yet. That’s why one of my cams went out. I’ll explain latter. Curtis, I guess you and I are the only one’s that destroy cam’s. Well the stock wore out with #10 lob being the worst a -.030. (5 ex) It was progressively better toward the front of the engine with the right bank trailing until about lobe 3 and 4. It is at the end of the food chain and on the wrong side of the engine. First failure was #10 lobe. It didn’t wipe it out but it stopped rotating and grooved the lifter. 2nd failure was a disaster I contribute it to to many rpm’s. With the t/g 160 chip the engine hits 3k when starting and then gradually settles down. I believe the damage was done at that time. I pre oiled the motor just prior to starting. Had to put the throttle body on of course. The last time I put the old mem cal in which started at 2k and settled down much faster. But I still have a problem with #10 so I put an oiler on it. Hay guys I can’t believe I made this post this long. Good subjects that we don’t see come up on this form much. I would encourage more to jump in. I love talking about cams. The more I talk the more I learn. Curtis, There’s no way w are going to run the cam‘s your running with alum heads. But would like to see your cam card for valve event. I see your ex follows your in intake in timing. Would be interesting. Can’t believe I wrote all this shit. Must be engrossed. I gotta go guy’s I’ve enjoyed. Keep it up. Jud Quote Link to comment Share on other sites More sharing options...
TurboZ24 Posted December 17, 2003 Report Share Posted December 17, 2003 Well, the problem I had with the wrong lifters on mine was they sent me standard SBC lifters, not the V6 lifters, that do normally have the "spitter" on them, ie the flat spot on the side of the lifter that sprays oil. Yes, oiling is a problem on the 3.1, since the cam sits in it's own valley, shielded from cranks splash. The flat tappet lifters I got from Crower for my last attempt at flat tappet lifters had a metered oiling hole on the actual lifter/cam surface. This worked great until I pushed more than the standard 8 psi at the time. I turned it to 16 psi and within 10-20 miles, all the exhaust lobes were gone. Here is my current mechanical roller cam card...... Advertised is 285/277 @.05" is 254/246 Lobe lift is .386"/.376" (I run 1.6 rockers) Intake Opens 18 BTDC Closes 57 ABDC Exhaust Opens 61 BBDC Closes 5 ATDC Lobe separation is 114 degrees Quote Link to comment Share on other sites More sharing options...
TurboGTU Posted December 17, 2003 Report Share Posted December 17, 2003 Wow...thats some info I can use!.. Thanks for the insite. But now more :?: :?: s .. Should I follow the cam break in procedure stated on the cam manual? Are you saying that I should just keep the engine presurised of oil before the breake in? What RPm should be Ideal during the break in?....I know SBC and most are at 3K rpm or more for 30 min..but theres no crank splash to the cam. WHats this little mod you made to feed oil to the lobes(pics?)? Exhaust going flat from too much power? Could it be posible that theres too much exhaust presure...that the exhaust valve acts like it has a supper high spring presure?(IE...120seat presure to 160seat presure during boost). If so...then its the oposite for the intake valve. (IE...120 seat presure to 80 during boost). Which brings up something else. Should the intake spring presure be higher and the exhaust spring be lower than stock? On Curtis cam...I got 23 degrees of overlap....but is that at .004 or .050 lift? I got more ?s....but thats enogh for now. Quote Link to comment Share on other sites More sharing options...
TurboZ24 Posted December 17, 2003 Report Share Posted December 17, 2003 Combustion pressure pushing on the exhaust valve was the thought, yes. Usually spring pressure is determined by the cam company. I currently use what was suggested to me, like 180 closed, 400 open (Have to dig around for the spring specs, though). My Cam card is stated at .05" tappet lift. Quote Link to comment Share on other sites More sharing options...
SleeperRed90TGp Posted December 17, 2003 Report Share Posted December 17, 2003 Sorry TurboGTU. For some reason I thought that was Davis’s post. On break in I ran between 1200 and 2000 rpm for ½ hour changing speed constantly. I would talk to your cam mfg and point out that there is no spray to the crank so why the high rpm’s. Curtis’s # are @050(intake open + 180 degrees + intake closing = duration). What is surprising about his cam is the advertised verses @050. It only gains 31 degrees where mine gains 56 degrees and we have the same duration. Must be the roller profile. I would have expected his cam to be into the 300 degree range. Maybe he will explain. I am only having a problem (so far) with the #10 lobe. Here’s a picture of the first install. I have since tucked the line underneath between the two lifters to get to the back of the cam. The oil is now coming from the main gallery so it’s getting oil long before it normally would and it gets a steady flow where it needs it. This can be done to all the lobes on that side with a larger initial line to tee’s along the valley. If I have any more trouble that’s next. As far as lighter spring, I don’t know if that would work. You still have to keep the lifter on the lobe when the valve is near wide open and closing and the pressure is off. Speaking of springs I ran stock springs with the first cam. (your cam is similar) Never had valve float to 6k rpm. Those 848 springs they recommend for your cam are some strong SOB’s :x As I remember they are almost double the # at gross lift. Jud Quote Link to comment Share on other sites More sharing options...
TurboZ24 Posted December 17, 2003 Report Share Posted December 17, 2003 It's the profile. The mechanical roller profile is pretty much a cylinder shape with rounded ends, unlike the egg shape of the hydraulic flat tappet. Here is my last mechanical flat tappet cam vs the roller http://www.turboz24.com/Pics/Cam_Compare3.JPG Some of the flat tappet lobes are gone, but notice the front lobes and the difference between them. Quote Link to comment Share on other sites More sharing options...
SleeperRed90TGp Posted December 17, 2003 Report Share Posted December 17, 2003 Hay there's Dave. Finally picked a cam. Prolly best choice you have for off the shelf. Note it's the same came that TurboGTU (h-260-2) is going to use. Don't know what the prices are between gm and Crane but I'll tell you, Crane stands behind there cams no questions asked. Been there done that 3 times. They even allowed me to chang grinds at no charge. All it cost me was the shipping of the cam back to them. The first time the cam had been in the car for about a year. I would check out gm's warrenty before you buy from them. It may even be worth a little more to go with crane just incase something does happen. I wouldn't want to argue with gm over a warrenty which is prolly 30' or 30 seconds, which ever occurs first. As for the oiling I don't know. I'am doing it because that lifter won't rotate. The 9 and 10 lifter are the last things in the motor to get oiled. Oil goes down the left side across the front and back down the right side and finally gets to 9 and 10. If you look and Curtis's picture of the two cames, guess what, 10 is wiped out. Can't see the others well enough but it looks like 9 and 10 are bad. I'll tell you this, it sure wont hurt it. I tried to get the squirt pointing at the bottom of the lifter just where it contacts the cam. Well so far so good, got 1k on it and no clicking. Its a bitch to bend the tubing to get behind the lifter. My last thought was to crimp the tubing and drill a hole crosways so it would get both lobes which would make it easier to route the tubing. I still want to see if the tubing has survied (not rubbing the lifters or the bottom of the lifters pounding holes in it.). If you do it try and keep the tubing in between the lobes of the cam. There's only about .100 between the lifters. My next endever, After xmas when I have some cash is to buy 1 set of Chevy hyd roller lifters and see how I can make them work. Pretty sure the lifters will work cause I bought a Chevy Hyd lifter and rocker arm to check them out. They will work. Biggest problem I see is the link bar. Ours lifters are so close together. Mayby Curtis could post a picture of his lifters along with the cam specs for 004. Would really like to see both of those. Thanks in advance Curtis. I'am not very knowledgable either in the cam field. as long as i keep destroying them and get into post like this the more I learn. Curtis, Thanks for the pic's. Iv'e run a roller before in a dragster with like 320 degrees duration. Well thats about what you have, that's why I was suprised at your duration. That cam must snap the valves open in a flash. Would you look at your cam and list the bad lobes so we can see if there on the left or right bank. Well gotta go put a different bait in the raccoon trap, can't seem to get the last one (i think) got mamma and poppa but the kid is evading me. I think he saw his parents in the trap. Jud Quote Link to comment Share on other sites More sharing options...
TurboZ24 Posted December 17, 2003 Report Share Posted December 17, 2003 Well, dug up the old cam. I thought I threw it out, but I didn't. If you start from the Sprocket side, #2, #3, #5, #6, #9, and #10 show signifigant damage. #1, #8, and #12 show a little flat area on the top of the lobe, so I guess only #4, #7, and #11 look to be completely undamaged. On rollers on the 3.1, You have to use rollers with deep skirts on them, since one bank is side oiled and one is through oiled. If the lifters don't have skirts on them, they will expose the oil gallery and puke oil. I believe the 3800 uses SBC bore size, but has deep skirts, since it is also side oiled. I looked for a picture of the lifters, but I've only got pics of them installed.... As for the cam specs at .004", I have no idea, only the advertised and .05" specs are listed on my cam sheet. The roller cam I have made a huge power difference. In fact, so much the engine breathes so well, my pre-turbo exhaust and turbine is too small to handle the amount of exhaust, so I'll have to upgrade. The pre-turbo backpressure is actually preventing the turbo from getting more than 14 psi of boost and drastically affecting my high rpm power..... Ops..... Quote Link to comment Share on other sites More sharing options...
maddux31 Posted December 18, 2003 Report Share Posted December 18, 2003 my # 10 lobe failed on my stock tgp cam. only 67,000 miles on the motor and the only performance mods at the time were k&n on turbo and ac coil fins removed in front of intercooler. bought a sealed power stock aftermarket cam and lifters for 140.00. good prices from my friend but not more than a 25.00 break. Quote Link to comment Share on other sites More sharing options...
Jeff M Posted December 18, 2003 Report Share Posted December 18, 2003 YES, the BP snake that bites back, gotten bit by that one myself while I was testing a TGP here. Here is what I found out that might help others. Stock turbo running with well done Gen II heads (these Gen IIs flowing within a few cfm on the exhaust side to a ported/polished Gen III head), and a stock cam; at 10 psi boost had 30 to 35 psi exhaust backpressure, no where near the target of 2:1 or 20 psi backpressure for 10 psi of boost as preferred (or better if possible). Swap to a larger T28 wheel and 25 to 30 psi, still too much. With this project I am trying to work within what is easiest, most affordable and successful for the hp goals of around 330 to 350 hp, and that is to keep a bolt-on setup so there are no added costs for custom crossover and downpipe (and no external wastegate), hoses etc. Garrett is sending another wheel to test but if that does not work, then looking at some tooling to make up a larger A/R exhaust housing as there are none on the shelf for this T25 (even calls to France where the TGP turbo was made yielded no help). From other tests this new A/R exhaust housing would benefit even totally stock TGPs engines-turbos setups. Now I know talk here is about larger cams and turbos but this should still shed some light on a few things, especially the point to shoot for a 2:1 or better BP to Boost ratio, though 2:1 is really good, better will be a bit of a challenge and may not be worth all the effort or compromises. Another key factor is exhaust pulse timing when fabing up headers and crossover pipes, the exhaust pulses should be such that they compliment each other as they enter the exhaust stream and prior to the turbine inlet. Last I will toss this one out there as some of the tuner guys I know/talk to like to throw a wrench in the common way of thinking, maybe just for fun…….to lower exhaust pressure you can cool it by not coating your headers (or??), exhaust air becomes more dense but has less mass/energy that has to go through the turbine housing, wheel and exducer, yielding less BP prior to the turbo….and if we do have too much BP then we must obviously have more than enough exhaust to spool the turbo !? Jeff M Quote Link to comment Share on other sites More sharing options...
SleeperRed90TGp Posted December 18, 2003 Report Share Posted December 18, 2003 Humm. Thought this was a cam discussion. Care to shed any light on the subject Jeff? maddux31 Did your cam go flat or did the lifter stop rotating and put a grove in the bottom of the lifter? So 5 out of 6 bad lobes are on the right bank, interesting. Jud Quote Link to comment Share on other sites More sharing options...
Jeff M Posted December 18, 2003 Report Share Posted December 18, 2003 Humm. Thought this was a cam discussion. Care to shed any light on the subject Jeff? Jud Oh it had some releation to the following: The roller cam I have made a huge power difference. In fact, so much the engine breathes so well, my pre-turbo exhaust and turbine is too small to handle the amount of exhaust, so I'll have to upgrade. The pre-turbo backpressure is actually preventing the turbo from getting more than 14 psi of boost and drastically affecting my high rpm power..... Ops..... But really its like any work done to an engine, its nice to know the effects and end results before hand or there can be a lot of time spent learning and going back to redo things that could be avoided with some help here. 8) So to be more clear, those looking to do cams to their TGP engine might need to look out for problems with backpressure or those excellent efforts to their engine rebuild/cam might backfire, so to say :shock: Jeff M Quote Link to comment Share on other sites More sharing options...
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