markz28

I would like to get this engine to pull more RPM that it currently does. What would be the best route, 1.6's or new cam? I called crane and they recommended a compucam 2020 194/204 @ .50 .407/.429 lift with a 1.5 rocker on a 111 degrees. Stock I have .350/.384 179/194 @ .50 I believe. Or does anyone else have a suggestion on a different cam. How about a L98 cam? From the specs on this website they have nice numbers and I could probably get a good deal on a used grind. Any preference to L98 years that will work with my computer best? I have a 91 Z28(auto) so it is speed density and I drive the car daily and don't want to have driveability problems. Other mods are ported plenum, all the free mods, dynomax cat back exhaust, no cats, performance resource chip, and 3.73 gears. Thanks for any help.

[This message has been edited by markz28 (edited March 12, 2001).]

The ODB

bigger rockers will increase power but unlikely to raise RPM range.
I like the L98 cams after 1988.

when you change cams you always risk having drivability problems.

theformula

08-304-8 comp cam
Don't forget you'll need another prom

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91 Formula
305 TPI 5speed
1LE/G92/WS6

Paxton SN92 polished kit, SLP airfoil, ported/polished plenum, March pulleys, Crane AFPR(43psi),Crane Gold 1.6rrs,MSD coil,MSD6AL (5200rpm limit),Holley 9mm wires,Ac delco R43ts plugs,stock chip,Ford SVO 24# injectors,Bosch O2sensor,SLP 1 5/8" headers,SLP catback,shortened shifter,3:73s w/Auburn posi,170* t-stat,JET 195* fan switch, Macewen white face gauges, Autometer gauges, Zoom hi-performance clutch.

markz28

I know swapping cams will affect driveability. But the factory cam really has nothing above 4500, I want something that makes power to 5000-5200. Crane said with speed density the stock cam should pull 21 inches of vacum and not to get to far away from that or the engine idle will search. Consequently the 2020 should pull 19 inches according to their tech. Any suggestions are helpful.

Steve89GTA

How do you like the performance resource chip?

Guest

Wrong cam. The argument is pretty much over that the 91 has the peanut cam, it has the bigger one used in the manual trans car and L98. That means theres a 202/207 .413/.428 cam in there right now. If you would like to witness the proof for yourself, go here:
https://www.thirdgen.org/messgboard/...ML/000513.html

I would get the 1.6 rockers.

[This message has been edited by madmax (edited March 12, 2001).]

The ODB

I just emailed you some classified info.




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*I do custom performance mods on Edlebrock Performer carburetors (dualplane intake mods in the works),
White 1986 Irocz, 305 with iron #416 heads,
383 with aluminum TFS heads,
Edlebrock Performer-RPM intake and Performer #1407 carburetor, +110hp shot of crack, 700R-4 tranny, Vigilante 2400 lockup converter, 3.25:1 Ford 9" rear, Mcreary Road-Stars, SLP-stainless 1.75" shortie headers & Y-pipe, single 3" Borla exhaust, Linginfelter-TPI camshaft part number 74216 pulls 17" vacuum solid. Cam specs 213/219 @.050 114-LSA, sometimes advertised at 216/219 @.050 112-LSA .462/.470 lift @1.5:1 ratio. Using Harland Sharp 1.65:1 roller rockers. MSD-6AL, billet distributor, multi-retard, blaster-3 coil, and RPM switch. SouthSide machine subframe connectors, SSM lift-bars, Moroso 4" underdrive crank pulley.

N/A runs 10.9 @124,
Crack-runs 10.3 @135
haven't run at track since Oct-99
* vizit miy homepayge * http://www.geocities.com/trailerparkpage/

Kevin91Z

iTrader: (1)

You should already have the L98 cam, so a cam with intake duration of 204 to 212 degrees (more duration means a lumpier idle)

Check out the cam tech article in the tech section of this website.

------------------
West Coast GM Shootout 2001!
1991 Camaro Z28
5.7L 5-Speed (originally 305)
13.25 @ 107.18 MPH
Southern California
Member: SoCal 3rd Gen F-Bodies
Webmaster: SoCal F-Bodies
-=ICON Motorsports=-

RB83L69

Here's about all the cam you can put in a 305 and still use the stock chip and valve springs...

COMPETITION CAMS CAMSHAFT SPECIFICATION SHEET

PART # 08-302-8
GRIND NUMBER: CS 264H-R12
ENGINE: CHEVY SM BLK 305-350
INTAKE EXHAUST
VALVE ADJUSTMENT HYD HYD
GROSS VALVE LIFT .480 .480
.006 TAPPET LIFT 264 274
VALVE TIMING OPEN CLOSE
AT .050 INT 3-BTDC 33 ABDC
EXH 46 BBDC 6-ATDC
THESE SPECS ARE FOR CAM INSTALLED
AT 108 INTAKE CENTER LINE
INTAKE EXHAUST
DURATION AT .050 210 220
LOBE LIFT .3200 .3200
LOBE SEPARATION 112
THIS CAM SHOULD USE SPRING # 981-16

IMHO the 304 is on the right track, but much too big for an otherwise unmodified 305 auto with no internal engine machine work.

The factory cam profile is very "lazy"; if you pull it out and compare the lobe shape to an aftermarket one, you'll see what I mean. The factory's still has egg-shaped lobes where the Comp will have much squarer-looking ones, which open the valves faster and hold them open longer. Even though the specs are not too far apart, there's a HUGE difference.

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"So many Mustangs, so little time..."
ICON Motorsports

markz28

Jeez I have not been around lately, been snowmobiling alot lately. Kevin I did check the tech articles and they listed the specs for the LB9, that is why I posted. Glad I did not order the cran 2020, would have been smaller than the L98. I still am not sure now what I might do next. Probably headers, Y pipe and either the cam or 1.6 ratio headers. I like the PR chip alot. In back to back weekends I went from a 2.21 60ft. 9.7 @ 72 in the 1/8 to a 2.05 9.41 @ 76 in the 1/8th early last september. Thanks for the response.

markz28

When I had my gears installed last summer the mechanic made a comment about the factory Ypipe. If you want to call it that, the passenger side bank is basically a 90 degree meeting point with the driver side. Definately will do exhaust after reading the thread highlited above.

formula14

I recently put the comp cams #08-302-8 and have noticed a signifigant increase in upper rpm power. Low end feels about the same but at about 3500 rpm it takes off. Depending on miles I would recommend changing the valve springs also. My car does not idle quite as nice as it used to but the extra power is well worth it.

Vader

Max,

You silly terrans.

There is only one thing wrong with the "proof" given at that link. Not all cam part numbers that were used in all TPI combinations are listed.

The most glaring mistake I see is the fact that the "all-inclusive" parts catalog page doesn't even include the cam from the '87 305 SEO vehicle, GM P/N 14093640.

Aside from that, none of the 1986 L98 cars are listed, and they all had a different cam part number since they were rollers (even though there were only about 75 built).

It also has been documented that many of the LB9 engines from 1990-1992 got the cam that was intended to be installed in the L03 engine (the "LA" cam).

Makes one wonder what else might be wrong with the page from the parts book. Have you ever gone to the dealer parts counter and got the wrong part, even though the part you are given matched what was listed for your car? That has happened to me more times than I can remember, and I know it has happened to others as well. Hell, that could be another complete board on this site...

Not to start a battle, but just because it is in print doesn't make it correct. I only wanted to point out the possibility that someone might have a car that deviated from "standard" a bit.

------------------
Later,
Vader
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"I'm'a do Things My Way - It's My way or the Highway."
Adobe Acrobat Reader

[This message has been edited by Vader (edited March 12, 2001).]

Guest

Okay.

Well I spec'd a cam out of a 91 LB9 too, and guess what it was? And no, it wasnt the manual trans G92 hipo go fast supposed different cam LB9 engine either. I also have a factory manual that I used to compare the specs I got and it only listed one type of cam. Same with the parts book listing in that link. I'm convinced, if you aren't then that is your choice and you are welcome to it.

Sure there are exceptions. My car is an example of one. There are other cars with exceptions out there too. But if you want to pick straws, then you should suggest he spec the cam first rather than assuming either value is correct.

As for parts, I sold parts for a number of years. I know the parts books, errors within, and differences in some cars. It is extremely rare for a car to deviate from whats in the book or what is known by the counterperson however. If I had to put a number on it, its about .1% If I was really generous, I might even say its 1%, but that IMO is exaggerating. The general rule when looking up or selling parts is to go by the book. The only case you dont is when you have the old part in hand, or you know the book is in error. If it arises that the part is in fact different from what its supposed to be, that is dealt with after the customer/retailer calls you back and starts whispering 4 letter words in your ear. Let me tell you those are things you remember, and being such I can tell you the occurance was not all that often. Of those times, about 1/4 was an updated or universal part that was being used in place of the original part. Case in point is today, I was at the local Chevy dealer and wanted a temp sender for my TA. The entire reason I went there was I wanted the STOCK type sender with the button end rather than spade clip, which is what the local mom+pop store tried to sell me. I really didnt and dont want to change my connector. So my friend, who so happens to not have his head up his rear, tells me it says in the computer its a spade type sender and you have to change the wire . I have a pretty good idea both of those parts are coming from the same building somewhere. So now I'm stuck with either trying to find a different manufacturer that doesnt want me to change the wire, or buy the mix+match part and change the connector. On initial inspection, yea its a different part. First inclination for most people, and reasonably so, is to call it wrong. Then you also have parts guys that can't find their head with both hands and a road map. Leaving them out of the equation of parts 'errors' is also a good idea.

I'm pretty convinced GM didn't use the peanut in the TPI cars from 90-92. I could go do some more research and check some more cams to verify it, but theres always someone who will disagree and say they have difinitive proof otherwise. Thats their choice. I'll just take my supposed peanut cammed 91 LB9 like it is and see if I can't hit 14's next time at the track, maybe passing one of them on the way to the line.

Ray87Z

If anything I think that is an isolated instance. One car having the better cam doesn't mean they all have it. I didn't think you knew what type of 91 the engine was out of??, or at least you're only going by what the prev owner told you about the motor (which as we know if often incorrect). For arguments sake lets say it's correct. You stated before I think that the owner said it was a non-G92 5spd car right? Who is to say maybe it's not just that all the 5spds that got the better cam, G92 or not unlike we had previously thought? People argued that for along time to start with, perhaps we were wrong.

There are too many questions here about this engine and just because one 5spd non-G92 car has the L98 cam doesn't mean all 305 TPIs, especially autos have the L98 cam. That is jumping to conslusions in a big way and is bad science no matter how you look at...

The argument is most certainly not over. However, if/when MrJ goes ahead and pulls his cam out and measures it then it'll be pretty much decided if indeed he also has the L98 cam and backs up your findings... There is no question he's got a 305 TPI auto w/ no cam work done by any previous owners and it will prove whats up.


There's always the possibility perhaps GM started using up extra parts since they would have already had the 4th gen pretty much in line for production, knowing they weren't going to be using most of the 3rd gen parts once the 92 model year was over, might as well dump some stuff you know...

Whatever the case, back to the original question the cam suggested up above is too small. I'm running a 204/214 cam in my 86 305 TPI, I would go bigger if I had it to do over again. However, you having SD instead of a MAF I'm not sure how big you get away with w/o slight drive-ability problems. I'd look at something in the 210/220 @.050 or thereabouts range for the cam if I were you. Stock, the TPI intake is limiting your RPM usuage as well as the cam though.

------------------
Ray87Z
-Vortec headed 350.
86 IROC w/ a cammed 305 TPI.
Formerly Ray86IROC.
www.inter-scape.com/Ray

[This message has been edited by Ray87Z (edited March 13, 2001).]

Box of Rocks

Max,

Vader and I must be going to the wrong parts counters. One out of 1000 is wrong ?????

Not in my lifetime - yet.

Try 1 in 10 - or 10%.

Oh, BTW - is everyone dead-nuts certain this guy is the ORIGINAL OWNER of the car in question ?????

If not, all bets are off - the only way to know for sure what you have is to hold said part in ones' hand AND LOOK.

GM is infamous for running out of parts on the assembly line and substituting whatever is available and will work -

This single fact has caused more "one off" Corvettes than anybody was ever able to order from the factory.

So, in conclusion, I will not take sides in this debate; I see merit in your aurgument Max, but I also see merit in Vaders' statement - as of now, I'd say the odds are with Vader.

Well, that should THROUGHLY P~SS-OFF everyone.

Oh man.......



BOR

Guest

I dunno Box, maybe my 8 years experience behind the counter doesnt give me any credit to say that. You are frequenting the wrong places is all I can say.

markz28

I had my buddy who has worked at the local chev dealer for 41 yrs. look up the cams for my car and a L98 and he said they are the same #. I mentioned the exhaust maniflolds, Ypipe, single cat theories on the previous post and he came up with this. If the .350/.384, 179/194@.050 peanut cam and the LO3 exhaust were used on the LB9 auto cars he said he doubted the LB9 could produce 205hp. Dale also thinks I should keep the L98 cam and run the 1.6 rockers and get a set of headers and Ypipe. He said typically the stock 350 cams like the L98 are a fairly aggressive cam in a 305. But a wilder 350 cam with more duration usually does not work very good in a 305 from his experiences. I called comp cams and the tech said the 8-302-9 should work without a hitch. But do the stock 305 heads breathe well enough to support a 210/220 .480/.480 lift cam? I really want to get this right and appreciate all the help.

Kevin91Z

iTrader: (1)

My dad put TPI on his stock 92 TBI engine with 210k miles, with the TBI manifolds, but a cat and cat-back from an 85 IROC. The car made 175 HP and 290 TQ at the rear wheels. If you compute the 15% drivetrain loss, thats 205 HP at the crank. And we know the TBI engine has the peanut or lameass cam.

Guest

Are you sure Kevin? <<<<---- sarcasm

Maybe you can pull a valvecover and check, the lift is quite a bit different, you could easily check it with a helper and a ruler. Im still betting its not Mr. Peanut.

[This message has been edited by madmax (edited March 14, 2001).]

Kevin91Z

iTrader: (1)

Why would they put the L98 cam in a TBI 305? It should be the peanut cam, the 179/194 cam, and nothing else.