Does anybody know the stock TGP cam specs?

**dbtk2** · 08-20-2003, 06:46 PM

Is the cam in the TGP any different than the n/a 3.1 cam. If so, what are the specs on the cam, and if not, what are the specs on the n/a 3.1 cam? Also, what is the most lift the stock heads can take, and what lift do the heads stop flowing well. If anybody can get me this information that would be AWESOME. Thanks.

Shawn

**Robby1870** · 08-20-2003, 08:30 PM

the lifts with the 1.5 rockers are .394 intake and .410 exhaust. Durations are 276 and 293. Those durations are NOT at .050". That is the n/a cam, and it is the same as the TGP cam. I *think* or heard somewhere that stock 3.1L springs can take a total valve lift of .500. As for flow characteristics, I have no idea

Robby

**dbtk2** · 08-21-2003, 11:46 PM

Thank you!!! Those helps tons...you don't even know. If anyone can get me more specs I would still like to get more, you can never have too many specs on a cam.

So did all 3.1's have 1.5 rockers, or did some have 1.5's and some have 1.6's. (maybe depending on year or something) Because if some had 1.6's, I may need to get my hands on some of those, if none had 1.6's, are 1.6's available??? I thought I saw someone (in fact it may have been you robby1870) that had 1.6 rockers in their mod list for their 3.1.

**Robby1870** · 08-22-2003, 12:00 AM

All 3.1Ls have 1.5 rockers. I think like 2000+ 3400s have 1.6 rockers, but dont quote me on that. As for the 1.6 install, it was me that did that. However, Im back on stockers now. The 1.6s rub the U in the guideplate and cause a vibration and eventually, the U-shaped piece on the guideplate breaks off, and a rocker starts hittin a retainer and other good stuff (trust me, I know, I was out 3 guideplates and two valve keepers). Oh, and the 1.6s put a strain on my stock 19# injcetors. So, if you want to fab up some guideplates, by all means go ahead. IMO, you're better off just buyin a huge cam ans using the stock valve train. However, I could DEFINITELY feel some major HP improvement in the 900 miles I Had them in. After breaking some guideplates once, then fixing it, then breaking some more, I was sick of it. Im just saving and building up another 3.1L

Robby

**dbtk2** · 08-22-2003, 12:20 AM

I already have a cam lined up...IIRC it is .423 intake lift and .423 exhaust lift with stock 1.5 rockers..don't remember the duration off the top of my head, but it its pretty decent, I was just trying to make sure it would work in the TGP and make sure it was bigger than what was already in there because I had no clue (i figured it was though). So with 1.6 rockers that brings it closer to where I want it, .4512 intake & exhaust lift. I want to be right around .475ish assuming the heads can flow well with those lifts. 1.7 rockers will get me .4794 intake and exhaust lift, and I am liking that, but 1.6's may have to do, because I think 1.7's will be a PITA to get to work. I want to get the Jeff M. P&P'ed heads when I can get some...I have decided against the 3100 head swap I was thinking about for a while there. But I would assume the P&P'ed Jeff M heads would flow better with higher lifts, so .450-.480 lift should flow pretty well.

I have the injector problem resolved, I am either going to go with 29lb. injectors to go with the Jeff M. programming, or I will use the stockers from the GTP (36lb.) and get some custom programming done so they work properly.

So...if I get some different guideplates made I shouldn't have any problems with 1.6's correct??? I am assuming that the guideplates for the 3400's that the 1.6 rockers belong in won't work correct?

Thank you for the information!!!

I still want info about the cam if anybody can get it for me. Thanks.

**TurboGTU** · 08-22-2003, 01:40 AM

Ummmm...3400s don't have guide plates. They use a machined slot on the head to keep the roller rocker in check(what a god send). For some geometry like this with bigger rocker ratios..you would need forged pushrods or chromoly ones. Heat treated or forged guide plates. Don't think anyone makes hardened guides for thise engines...but push rods could be costom. Im (trying to)making stock 96.5-97 3100 roller rockers work on my 2nd gen heads. I could omit the guides then. Valve lash would be an issue I would run into with this as the 3400 people do...no adjustment unlike the 1st,2nd gen heads. I've heard Jeff I think,,prob someone else,,, metion that just .1 more lift rokers on the exhaust would work well.

On cams I am more concerned on split pattern and lobe seperation. More exhaust... more seperation (112-114) all boost friendly cam. Hell the stock cam specs with just an lobe seperation of 114 would help alot. Stock is 109 I think. Oh ,but the computer...damm...tunners?....

**dbtk2** · 08-22-2003, 02:08 PM

Ummmm...3400s don't have guide plates. They use a machined slot on the head to keep the roller rocker in check(what a god send). For some geometry like this with bigger rocker ratios..you would need forged pushrods or chromoly ones. Heat treated or forged guide plates. Don't think anyone makes hardened guides for thise engines...but push rods could be costom. Im (trying to)making stock 96.5-97 3100 roller rockers work on my 2nd gen heads. I could omit the guides then. Valve lash would be an issue I would run into with this as the 3400 people do...no adjustment unlike the 1st,2nd gen heads. I've heard Jeff I think,,prob someone else,,, metion that just .1 more lift rokers on the exhaust would work well.

I don't know ANYTHING about the 3400 except for the fact that it is a GM 60 degree pushrod V6. That is it, that would be why I didn't know they don't have guide plates. I am definately going to be looking into chromoly pushrods for it, I don't think they are available, but I may be able to get them custom made. All I really have to do is figure out how/where to get guideplates for 1.6 rockers. I have heard that Jeff M. has 1.6 rockers, so I will talk to him and see if he can tell me how it is done. I don't want to go crazy with the cam on the TGP, I just want to wake it up a bit and get some more power out of it (looking for 15-25hp and 20-30lb. ft.).

On cams I am more concerned on split pattern and lobe seperation. More exhaust... more seperation (112-114) all boost friendly cam. Hell the stock cam specs with just an lobe seperation of 114 would help alot. Stock is 109 I think. Oh ,but the computer...damm...tunners?....

The cam that I have found is .282/.282 (.423/.423 w/1.5 rockers) w/204 intake duration @ .050, and 214 exhaust duration @ .050. The lobe seperation unfortunately is still 109, I really want it to be like 112-114, but it isn't. They stressed that the cam will work with stock computer, but I don't know about that with 1.6 or 1.7 rockers also. The one problem I am finding though is that it says it is for 81-89 2.8, 3.1, & 3.4's, so I am wondering if it will work in a '90 3.1, I don't know what they would've changed in '90 that would make it not work, so I am confused about that. Advertised duration is 264 intake/274 exhaust, and so I don't know if that is better than stock or not. Robby1870 said that duration was 276/293 on the stock cam, and if that is the same duration as the 264 and 274 numbers this cam has, this cam may not be much, if any better than the stock one. If anyone has any imputs on this, please let me know, I really want to see if this cam is any good or not.

**dbtk2** · 08-22-2003, 02:43 PM

I just found another cam, but it is a 2.8L cam, and it is supposedly only for '82-'86 2.8's. Did they change the 2.8 enough that it won't work in later years, translating to it not working in the 3.1???

The specs on the cam seem a little better. Here they are:

Advertised Duration:

253 Intake
263 Exhaust

Lift:

.420 Intake
.442 Exhaust

Duration @ .050:

204 degrees Intake
214 degrees Exhaust

Lobe Seperation: 112

These specs make the cam look very nice IF it will work in a 3.1L.

I also found 1.6 ratio rockers with roller tips for the 2.8L. Will these work in the 3.1?

If the cam and rockers will work that will put me at .448 Intake Lift and .472 Exhaust lift. That is just about perfect if it will work. If someone could tell me if these will work or not, that will be awesome. My guess is they won't work, or else the 3.1 would be listed as an application, but I figured I may as well check since the cam & rocker profile together are almost exactly what I am looking for.

**Robby1870** · 08-22-2003, 05:19 PM

Ha, those rockers you found are the ones I tried puttin on. They are from Comp Cams arent they? Oh, and a 2.8 RWD cam will work in a FWD 3.1L, same block=same placement of lifters=same cam

Robby

**Chris A** · 08-22-2003, 05:32 PM

The confusion with the cams application isn't surprising.

Alot of it comes from older listings that aren't updated when the motor was more popular for cam swaps (IIRC, it was used for circle track etc). And some misunderstanding by cam companies about DIS and the cam. For some reason (you may see this noted in places) they think that starting in 1988 with the internally balalnced crank and the crank trigger that the cam also had a trigger for the cam sensor. In reality only GEN III engines (AFAIK) have a cam sensor, furthermore they are roller.

So because of the implementation of DIS they limit the appliation list to 1986. However, all cams will work for all 60 motors until approx 1994. As long as it doesn't have a cam sensor it will be ok. Some cams will have the lobe for the fuel pump and some won't, but it won't matter in a fuel injected car anyway.

**Robby1870** · 08-22-2003, 05:42 PM

Originally Posted by Chris A

The confusion with the cams application isn't surprising.

Alot of it comes from older listings that aren't updated when the motor was more popular for cam swaps (IIRC, it was used for circle track etc). And some misunderstanding by cam companies about DIS and the cam. For some reason (you may see this noted in places) they think that starting in 1988 with the internally balalnced crank and the crank trigger that the cam also had a trigger for the cam sensor. In reality only GEN III engines (AFAIK) have a cam sensor, furthermore they are roller.

So because of the implementation of DIS they limit the appliation list to 1986. However, all cams will work for all 60 motors until approx 1994. As long as it doesn't have a cam sensor it will be ok. Some cams will have the lobe for the fuel pump and some won't, but it won't matter in a fuel injected car anyway.

Yes, the 2.8s RWD were used in some circle track racing. So, there is a huge aftermarket for parts for them. Most are exhaust systems, intakes, ignitions, etc, stuff that we cant use. BUT, the internal motor stuff will work (minus the 1.6 rockers, from what I have found). The RWD 2.8s had inline valves whereas ours has splayed. RWD 2.8s had iron heads as well. But, cams, and pistons and stuff like that does apply. There are NUMEROUS cams out ther for the 2.8. Some are VERY aggressive, way more than what dbtk2 has found. However, some are really hot (by that I mean the durations at .050 are VERY long). I dont think the really hot ones would be very good for our motors. However, there are some good in b/n ones, that still offer good lifts as well as durations at .050 that will give it a nice loping sound.

Robby

**dbtk2** · 08-23-2003, 01:05 AM

I figured the cam would work, but I just wanted to make sure they didn't upgrade the block since then, translating into the cam not working.

Ha, those rockers you found are the ones I tried puttin on. They are from Comp Cams arent they?

Yup, those would be the ones...but they should work as long as I get the guideplates machined.

There are NUMEROUS cams out ther for the 2.8. Some are VERY aggressive, way more than what dbtk2 has found.

I figured there were, but I didn't know where I could find some, and I want to know where I can find some!!! The ones that I am finding are wimpy (you saw the biggest one I could find...kinda wimpy isn't it) and are going to require me to use higher ratio rockers to get the lift I want, and why do that if I don't have to. All I reallly need is for you to point me in the right direction for the aggressive cams and I should be able to find the one I want.

The cam that I am looking for is: (the perfect cam for the car in my mind)

111 Intake Centerline
114 Lobe Seperation
.317 Intake Lift (.4755 valve lift)
.320 Exhaust Lift (.48 valve lift)
212 degrees Intake Duration @ .050
220 degrees Exhaust Duration @ .050

If you could find a 2.8L cam that is close to that (a little larger or a little smaller) let me know and tell me where I can get it, or point me in the direction where you think I may be able to get it. I did not realize there was any aftermarket for the 2.8's, so I figured there wasn't much out there...now that I find out there is, I want to know where it is.

Thank you for all the help so far!!!

**Robby1870** · 08-23-2003, 12:54 PM

www.cranecams.com There's plenty there

Robby

**dbtk2** · 08-23-2003, 05:40 PM

Thanks robby1870, I will take a look and see what I can find.

Shawn

**dbtk2** · 08-23-2003, 06:37 PM

OK, I think I found a cam that I like here. What do you think:

112 Lobe Seperation
.454 Intake Lift
.480 Exhaust Lift
216 Intake Duration @ .050
228 Exhaust Duration @ .050
272 Advertised Intake Duration
284 Advertised Exhaust Duration

I will also be getting new valvesprings, retainers, lifters, pushrods, and 1.5 full roller rockers. I figure while I'm in there I may as well do it right. I figure with the 105lb. valvesprings, the new lifters and pushrods, and the full roller rockers I should be able to safely shift at 6000-6500rpms without risking breaking things, and the cam should help it make more power up there. Let me know if you think this is a good setup or not. If you see something that doesn't look like it is going to work, or if there is something you would do differently, LET ME KNOW.

Shawn

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