Transam461

Hi, we are building a 1972 455 Olds that is getting freshened up for my 1979 Trans Am. I am new to Oldsmobile engines, as I have always ran Pontiac stuff, so I'm still learning Oldsmobile. It is a 1972 455 block, it has 67-69 "C" heads on it, and after cleaning them up, it appears that have been "pocket ported". I also found ".020" stamped in the decks, so I would almost bet they have been milled .020" as well. They have ARP Rockers Studs and guide plates. The Pistons are SpeedPro L2323 dished forged piston, 18cc dish. The current camshaft, that was in the engine already when I obtained it, is a hyd flat tappet JM 25-28, 280/292 Advertised duration, 236/248 duration@.050, .523"/.544" lift, 108* Lobe Seperation, not sure what the Intake Centerline is suppose to be. It looks like a pretty hefty sized camshaft for a street engine to me. It has Comp Cams 1.6 roller tipped rockers and Poly Locks. I will use Corteco .028" head gaskets. Compression falls around 9.5 or 9.6-1 for this combination. Intake is a Edelbrock Performer with a 750 Holley. Ignition is all Flame Thrower. So, being familiar with Pontiacs, most people have found that it is better to stay away from the "narrow" lobe seperation, "fast ramp", short seat duration camshafts, like the one that is currently in this engine, for their Street engines. Some known pontiac engine builders have found that the pontiac engine seems to favor, longer seat duration camshafts, with a slower ramp, and prefer a wider lobe seperation, such as 112° or 114°. I would assume, since the Olds engine is a long stroke engine as well, the same would apply. So my question is, should I change out the camshaft to something better while I have it apart, to better suit my intended usage? I've did a little research, and it seems the Erson 545321(JB100) gets recommended alot, as does the same camshaft, but on a 110° lobe seperation, refered to as the "TQ50". These camshafts have 296/306 Advertised Duration, 228/235 duration@.050", and .504"/.504" lift and either 110° lobe separation or 112°. I'm sure there is a lot of other good camshafts out there as well. Due to budget at this time, I will be sticking with a hyd flat tappet. The car is a 3800 lb 1979 Trans Am, TH-350, 2600 Stall converter, and 3.23 gears. The application is 100% Steet driven on 91 pump gas. I prefer a racy sounding idle, as long has the power brakes aren't affected, and makes a ton of low end torque. Is it worth it for me to change the camshaft in this combination, while I have it apart, or just use the current Mondello camshaft? If so, which hyd flat tappet would you recommend? The current camshaft sounded good at idle, and didn't seem to affect my power brakes, but looking at the specs, it seems pretty large for what is usually considered a high performance street camshaft, plus being on a narrow lobe separation.


Any help or suggestions would be great, Thanks!

OLDSter Ralph

How long have you had the car ? How many miles have you driven it ? 3800 pounds, 2600 stall convertor, TH350, and 3,23 rear gears...........
The cam you have is probably "good enough" for what you have. A new cam and lifters will cost you $300, would it be worth it ?
There's a guy on here Cutlassefi that might give you better advice.
........Just my two cents worth.

Transam461

Thanks, I haven't really driven the car much at all, just to the local gas station a couple times before we decided to pull and freshen the engine. It ran decent I guess, but I have since found out that it had only 2.73 gears, and a single track. It now has a 3.23 posi, for when the engine goes back in. It just didn't seem to be the tire burner I thought it would be for a 455 olds. It seemed to me that it lacked low end torque, but alot of that could have been those 2.73 gears. I would like to go ahead and change the camshaft for a better grind right now, rather than doing it later, if it could benefit from a cam change. Looking at the specs of either that TQ50 or the JB100(same cam, one has 110 lsa, the other has 112), it seems it would be a better grind than what I currently have for low end tire burning power for the street. I would be more than happy to change it, if it were to make a drastic difference in the low end. During my search here, I found a guy with a very similar combination, and he ran the Erson JB100 camshaft(296/306, 228/235, .504"/.504" 112° LSA), and said he could do 300-400ft burnouts with a 2.56 gear. Mine sure wouldn't do that with the 2.73's and single track. That is what got me to thinking about a cam change. The engine was in great condition when we tore it down by the way...

1969w3155

As mentioned above contact Mark aka Cutlassefi as he is a Lunati and Erson rep. plus he builds Olds engines. Use the "Community" tab above, and then the members link. Use the search function partway down the page on the right to do a search.

OLDSter Ralph

2.73's are not good. 3.23's are better. An "open" rear end should have burned some rubber. I am suspecting the engine wasn't tuned right, since you mentioned the engine was in great condition when torn down. If you are determined to change cams, the TQ40 might be ok. I don't know much about the TQ50 and power brakes.
Burnin rubber doesn't mean a thing. You can pump the tires up to 40 psi and do that.

svnt442

I ran the JB100 and had zero issues with power brakes. I can't believe that the TQ50 would have any issues.

cutlassefi

A few things. Was that cam degreed? Probably not.
That cam also has too much exhaust duration for the combination. That effects low end power as well.
With your combo I’d actually do the TQ50. The tighter lobe sep will help low to midrange power. HOWEVER ALL cams need to be checked AND don’t trust that your carb is jetted correctly either. Chances are it isn’t. That needs to be addressed as well if you haven’t already.

svnt442

That would be me. The car was a 70 post and had a 2.56 posi. I was running untouched (except for a valve job) J heads, Erson JB100 cam, TRW 2323F .030 pistons, Mallory Unilite distributor, Performer intake and Edelbrock 1407 750CFM carb. I had a TH400 with a B&M holeshot torque converter. It was a very simple combination and ran well for what it was. I got a best time of 13.89 @ 97 mph going through the traps in second gear.
The damn thing was a burnout machine on the street. All I needed to do was take my foot off the brake and slam down on the gas and the tires would light right up. Thank god I had access to cheap tires at the time...lol.

Transam461

Thanks Mark, yeah, im not sure if the camshaft was checked with a degree wheel or not, I do know it was installed "dot to dot" when I removed it. We always check every camshaft with a degree wheel when installing, to make sure they are installed at the desired centerline. The TQ50 is the camshaft I was leaning toward the most, as it looks like a perfect sized camshaft for a big street driven 455, without losing much low end, while still sounding nice at idle. I expect that there would be a big improvement in low end feel on the street over the camshaft that is currently on hand, if everything is tuned correctly of course. For the carb and distributor, we may get in contact with Cliff Ruggles, and get the parts to build a Qjet for it with the correct specs and have the distributor recurved. Could you PM me a price and lead time on the TQ50 camshaft? I already have a new set of lifters, and a new Cloyes Street True timing set, so all I will need is the camshaft. Thanks Mark

Transam461

Yep, it sure was! Lol ... Very cool, simple sounding combination. Really, that's what we are after with this combination, is a fun street car with a lot of low end. I just think the TQ50 would be way better suited for doing just that, over the bigger camshaft that we currently have. Thanks for the help

svnt442

The car probably would have done a little better in the quarter with a TQ50, but we had the JB100 sitting on the shelf at Super Shops where I worked and I didn't feel like ordering a cam, so that is what I ended up with. What I was told by Steve Tanzi (used to be THE cam guy at Erson many moons ago) was the JB cams were designed for low end to get the boat out of the water with as much grunt as possible. It was fun either way.

Transam461

Well... We placed our order for the TQ50 with Mark a few minutes ago :-)

Transam461

Just an update guys... I got the Erson TQ50 camshaft that I ordered from Mark just a few days after I placed my order, shipping was very fast. We installed the camshaft today and degreed it to see where it was at with our new Cloyes 9-1113 timing chain set, starting out with it installed dot-dot. To our surprise it came in at 105.3° Intake Centerline, Cam Card states to install it at 106°, so by the time you figure in a tad bit of stretch from the new chain set after break-in, it should come out about perfect, so we are going to leave it as is. Thanks to everyone here for all of the help, and Thanks to Mark for the new camshaft, can't wait to see how it runs.

VinMichael

Good deal. In my 455 I'm using an Erson Hiflow 228/228 at .050 on a 108 with .504 lift. Springs set to 105 lbs on the seat.
Car runs sweet. In 3.5 degrees advanced.

Transam461

Nice, Thanks!