I recently got a new camshaft from RockAuto and I noticed some very slight differences. I wanted to run it by you all to see if you think they are anything I should worry about or if it is safe to ignore.


Original Camshaft is in top of this picture / enginetech is on the bottom


Original camshaft is on the right side / enginetech on the left

[This message has been edited by Cunnive (edited 04-03-2020).]

Looks like the lobes are higher...on the enginetech cam. (Wear??)

[This message has been edited by fierogt28 (edited 04-03-2020).]

Please be more specific what you are concerned about. Assuming on the end shot you are concerned about the raised boss (green arrows), as long as the cam gear fully seats you are good to go.



On the side shot are you concerned about the missing 'hole' or much larger height/diameter of the land region (red arrows)? LOL, I don't know what that is called or what it does. Experts??

Yes, I was wondering if the difference in the raised bar was an issue as well as the larger hole on the enginetech camshaft.

I also measured each lobe for both camshafts and here are the results going from the rear of the camshaft to the front end towards the timing chain/water pump.

The first number is the lobe lift / second number is the lobe heel in millimeters.

Enginetech camshat | OEM camshaft (73k miles on it)

1) 40.2 / 33.5 | 36.5 / 32.00
2) 41.01 / 35.11 | 38.19 / 33.5
3) 40.18 / 33.5 | 38.19 / 31.9
4) 41.01 / 35.11 | 37.9 / 33.5
5) 40.20 / 33.47 | 37.1 / 31.9
6) 40.98 / 35.11 | 39.49 / 33.50
7) 40.98 / 35.10 | 39.30 / 33.55
8) 40.12 / 33.47 | 37.02 / 31.87
9) 40.95 / 35.07 | 37.85 / 33.50
10) 39.79 / 33.5 | 35.75 / 31.95
11) 40.95 / 35.10 | 38.44 / 33.57
12) 40.12 / 33.5 | 38.63 / 31.95

I only bring this up because this is the first time i'm doing this and I just want to make sure I am not putting in a defective camshaft in my V6 2.8L engine. The numbers appear to be ok but I did notice some of the same lobes for the intake or exhaust aren't perfectly pointed in the same orientation. For example: On the Enginetech camshaft, lobe 1 and lob 3 measure almost the same but there is about a 2 degree difference between where the 2 lobes are pointing. Is that anything to worry about?

Thanks!

I'm guessing that you are using the ES1539.
Its advertised lift is .390 / .409. (I / E) The advertised lift for the stock Fiero cam is .394 / 410. Essentially identical.
The advertised duration is also fairly mild. I don't remember exactly what the Fiero cam duration is, but it's nothing spectacular.
Also, it appears that this cam is also offered as a direct replacement for the VIN "S" 3.4 engine, which coincides with what I have always heard... That the cam specs for the 2.8 Fiero and the iron head (Camarobird) 3.4 are essentially identical.
The first set of pics that you posted show a tab on the "new" cam, next to the front bearing, that is not a part of your Fiero cam. That tab is used to trigger a cam position sensor on the 3.4, that is used for sequential EFI. A bit more advanced than the Fiero's batch fire EFI.

With that said... I can't comment on the measurements of the lobe heights. The lobes on the new cam look "bigger" than your original cam, but that must also be based upon a comparison to the base circle.
Regarding the position of the lobes, I wouldn't think 2-3 degrees would make a huge difference, but I certainly can't speak from a position of authority. I really don't know.

Edit - Yikes! I just realized (from the thread title) that you are using the ES715. It is a much milder cam than the stock Fiero Cam. (I'm guessing it's probably similar to the cam that was used in the 3.1 minivan engines. Lots of torque, but less peak power.) Compare the specs to the ES1539, and to the specs that I posted for the stock Fiero cam. The 1539 will be a very close replacement to your stock cam.

The 715 will probably work okay in your engine, but it won't be as strong as stock. Probably not what you are looking for.

[This message has been edited by Raydar (edited 04-07-2020).]

Thanks for the response Raydar.

I do plan on swapping out the transmission for the 4T60 so would you suggest that I get the ES1539 with that transmission in mind?

quote Originally posted by Cunnive: Thanks for the response Raydar. I do plan on swapping out the transmission for the 4T60 so would you suggest that I get the ES1539 with that transmission in mind?

Yes. Absolutely. The automatic Fiero used the same cam as the manual. It's still a fairly mild cam, in the grand scheme of things.
The 4T60 was really a 125C with a 4th gear, from everything I've ever heard. Just use a torque converter that has a similar stall speed as the stock Fiero's.
There is some torque converter info at this link. Scroll down.
http://www.gmtuners.com/gmtransinfo.htm
Edit - It appears that you can use a stock 125C converter with a 4T60, (pre 1996) based upon what is in the document.

I was actually going to recommend something like a Crane 260-1, but it appears to be out of production.

[This message has been edited by Raydar (edited 04-08-2020).]

quote Originally posted by Raydar: Yes. Absolutely. The automatic Fiero used the same cam as the manual. It's still a fairly mild cam, in the grand scheme of things. The 4T60 was really a 125C with a 4th gear, from everything I've ever heard. Just use a torque converter that has a similar stall speed as the stock Fiero's. There is some torque converter info at this link. Scroll down. http://www.gmtuners.com/gmtransinfo.htm Edit - It appears that you can use a stock 125C converter with a 4T60, (pre 1996) based upon what is in the document. I was actually going to recommend something like a Crane 260-1, but it appears to be out of production.

Can you recommend a set of lifters that go well with the 1539 camshaft? I am not doing any performance upgrades, just want to match the camshaft with a nice set of lifters that goes well with it.

Ty again!

I'll have to defer to some of the others, who will, I'm hoping, chime in. I have heard that Crane lifters are substandard, and have heard recommendations to use stock replacement GM lifters (which seem to be rather spendy, if I remember correctly.)
It's been probably 15 years since I did my cam and lifter swap (this was in a 3.4 that I built up. I really don't remember what I used. They held up fine until this past year, when a more recent owner ran the engine out of oil, and wiped a lobe. (An oil feed line broke. Pumped the sump dry.)