Boxman Posted December 24, 2011 Report Share Posted December 24, 2011 I'm currently rebuilding a standard '95 B5234T engine to deliver ~400HP, and I'm now at the point that I can put the cams in. What I've upgraded so far is: - Head professionally rebuilt - Engine block bored + honed to 81.5mm Wiseco size - Camshaft checked - H-beam conrods - Forged Pistons (Wiseco) and rings So for the cams, I read a lot of throwing in GLT cams for they have longer duration and higherlifts. I'm asking what the pro's and cons of a GLT cam are. I've heard some rumors; - Does the GLT cam make the engine run 'less smooth' because of increased resistance due to high lift/duration? - Is there a risk at high RPM's for "jumping lifters", ie the springs not being strong enough to push the lifters back fast enough? - Is the mod necessary for 400HP, and is a wall reached if this mod is not installed? Link to comment Share on other sites More sharing options...
Jardim Posted December 24, 2011 Report Share Posted December 24, 2011 The cams are a nice addition, a ECU tuned for your setup along with the right timing on the cam gears will allow your engine to run smooth despite the longer duration on the cam. As for the "jumping lifters" i have never heard of such an issue. Maybe someone else can shine the light on the matter. Link to comment Share on other sites More sharing options...
BoostedS70 Posted December 24, 2011 Report Share Posted December 24, 2011 you mean N/A cams. Glt is also known as a low pressure turbo model, or early models of 850 were N/A glts. but most people on here refer to the glt as a tur bo. I have a 70 GLT and it is the same exact motor as your car just a little higher compression due to a taller piston crown. but cams are the same. you want N/A cams which have more lift and longer duration due to bigger lobes than the turbo cams. these cars also have hydraulic liffters you dont have to worry about jumping lifters. I have never heard of anybody having a problem with that. you say 400hp so im sure you would be able to utilize them, just gota time them and mess around with the overlap try to get it as little as possible. Link to comment Share on other sites More sharing options...
Jardim Posted December 24, 2011 Report Share Posted December 24, 2011 I had a hunch he was talking about the N/A cams when he said longer duration and higher lift. Some people say the 93 cams are the most agressive of them all...can anyone confirm this? Link to comment Share on other sites More sharing options...
wizzard_al Posted December 24, 2011 Report Share Posted December 24, 2011 "jumping lifters" is something that you might see on an overhead valve engine, such as Chevy V8's, Volvo red block up to B20 engine. It is also known as valve float, when the weight if the lifter, pushrod, and the rocker arm are so much that the spring can't push it back fast enough for the lifter to stay seated on the camshaft at all times. Typically at high rpm, and it means that it is a destuctive way of limiting your rpm. Volvo has overhead cam, so this is a rare event, but could happen if you were twisting it to unholy rpm. But look at lookforjoe's car, he reports over 8,000 rpm, and I don't think he has gone to much stronger springs. (Hussein, correct me if I'm wrong). Other posters have gone over 7,000 rpm with stock valves, so you don't have any real problem to think about. Note that hydraulic lifters do "pump up", which means that they can't drain oil out of the lifter fast enough, and they tend to lock into one length, which may not be useful for the engine, and that is the hydraulic equivilent to valve float. Same problem, too high rpm for the lifters to keep up. Again, doesn't seem to be a problem for whiteblock engines. Later engines, from mid '99, have mechanical lifters, but they also have VVT on exhaust cam for turbos, and you can adapt those heads and cams, because the head flows better, supposedly, but playing with the cams to adapt VVT cams to non-VVT operation takes a bit of work. There is another thread on this topic. Link to comment Share on other sites More sharing options...
lookforjoe Posted December 25, 2011 Report Share Posted December 25, 2011 Others have run the stock (hydraulic) lifters to 7600. I have the later solid lifters, running to 8400rpm. Sounds like you have a solid build underway. No reason to worry about idle issues - the NA cams aren't that agressive :D Link to comment Share on other sites More sharing options...
Boxman Posted December 25, 2011 Author Report Share Posted December 25, 2011 What a great info I always get here. I meant NA cams indeed. So I think I can just safely drop in some NA cams - it's something I would want to do NOW, right? And not later, when the engine is in the car? Will my engine be ready to run with a stock turbo with the NA cams on the NA timing? Or should I immediately do the timing (i read something about 4 degrees retardation on the exhaust, have to jump into this some deeper) to get the T5 timing window? Also, what are the power gains I'll be seeing from this, assuming I'd want to reach the 400. Say I reach 400 with NA cams, what would I have reached with stock cams? Link to comment Share on other sites More sharing options...
Martijn_B Posted December 25, 2011 Report Share Posted December 25, 2011 With the right timing a guy from the Dutch forum gained around 30bhp with a 19T (335 to 367). Link to comment Share on other sites More sharing options...
Commander Riker Posted December 27, 2011 Report Share Posted December 27, 2011 I have a set of NA cams that I going to sell. Drop me a PM if interested. Good luck to your build. :) Link to comment Share on other sites More sharing options...
850wagonT5 Posted December 30, 2011 Report Share Posted December 30, 2011 No one has posted definitive numbers as far as a power increase. I "think" I noticed a "small" difference on the "butt dyno", but if you're spending money building an engine, do the cams right - get CAT's and KNOW for a FACT you're going to be producing a good amount more than stock...instead of guessing. A good performance camset will pretty much always be enough of a difference in pull to where you KNOW they made power. With the GLT cams, it's usually "I think they did something...it seems to pull a little better up top...". See the difference? I have GLT's but I'm not convinced they did much. If I was building a head, getting rods, pistons...I'd get real cams. Link to comment Share on other sites More sharing options...
Jardim Posted December 30, 2011 Report Share Posted December 30, 2011 You'd probably get or feel more outta the N/A cams if you had a 5 speed BTW Im going by the sig, 13 is quick would be faster with the 5 speed. Link to comment Share on other sites More sharing options...
850wagonT5 Posted December 30, 2011 Report Share Posted December 30, 2011 You'd probably get or feel more outta the N/A cams if you had a 5 speed BTW Im going by the sig, 13 is quick would be faster with the 5 speed. Car already traps 110. Car already traps 110. I should say 110+, walks 335i's hard...walks a friend's 380whp SRT8 hard...haven't lost to stock turbo STI yet. I have NO interest in going manual, really...it's just too much money and time and work. PS, go E85. It's fun. ;) Link to comment Share on other sites More sharing options...
dfer10 Posted December 30, 2011 Report Share Posted December 30, 2011 who makes performance cams for our cars? Link to comment Share on other sites More sharing options...
GltGreco Posted December 30, 2011 Report Share Posted December 30, 2011 who makes performance cams for our cars? not many and as far as i know they are extremely expensive. Link to comment Share on other sites More sharing options...
andyb5 Posted December 30, 2011 Report Share Posted December 30, 2011 Cat and Enem make performance cams, but both companies are based in Europe and are expensive. For more specific info, Lookforjoe has Enem cams in his XR 854TGA+ and Falcone have Cat cams in their 850s. Link to comment Share on other sites More sharing options...
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