Just pulled an original factory cam out of a 92 5.0 TBI engine. It's got no fuel pump eccentric on it. Everything else I've ever pulled out of 3rd gen EFI engines (including earlier TBI motors) has always had one. So for those who for various reasons want to put a block-mounted mechanical pump on their 3rd gen engine it's not always going to work. I have done it several times and never had a problem where the cam didn't have the eccentric, but that now looks like nothing but dumb luck.

Don't say you haven't been warned. It certainly came as a surprise to me.

Please note: I'm also a guy who ripped into an original 87 5.0 TBI engine and found a flat tappet cam in it, so odd stuff seems to seek me out!

 

Thats useful info to know.

Was the 87 block from an 88 camaro, or was it from a truck? IIRC, most of the earlier trucks just had flat tappets instead of teh factory roller.

 

It was out of a Camaro. It was my contention at that time that a truck TBI engine somehow made it under the hood of my Camaro from the factory. Never did figure it out for sure.

In other news..... I had responded in a post about this same subject just a few weeks ago that I had a 92 5.0 TBI cam that DID have a fuel pump eccentric. It was a different cam from a different engine than what I just pulled out yesterday. Now I'm trying to figure out whether......

1. It really was another 92 TBI cam that does have a lobe (i.e. some cams got them and some didn't for inexplicable reasons)

2. I lost track of which cam I was holding in my hand at it's actually from a TPI or an earlier engine.

 

i just replace my 91 rs cam not that long ago for an l98 cam , this is why its running like crap now but i dygress, and i dont remember seeing any fuel pump eccentric on it. i still have it inn my garage but ill look again.

 

Here is the stock cam out of my 90. It has a pump lobe. It doesn't suprise me that some of the 87 cars had a flat tappet seeing how some of them also had the left over 416's. Did you measure the specs on that cam to make sure that it was 100% stock?

 

....

[Edit] Wrong thread my bad...

 

I think mine was an 87 casting and it got the roller. Not that it helped very much. I guess gm liked to mix'n'match parts.

 

the cam that cam out of my 91 lo3 did not have a fuel pump lobe, and I have seen one noroller cam come out of a camaro but it had been replacement warranty motor, as the owner said the motor took a dump about a month of buying the car new from the dealer.

 

Shifty- I did not measure the specs on the oddball 87 cam. Had no reason to believe it had been replaced and I never had a TBI motor apart before so I just assumed they all came with flat tappet cams. This was probably better than 10 years ago.

I also have not measured the specs on this 92 TBI cam, either, but once again, I have no reason to beleive it's not original. I'm the 2nd owner and engine shows no signs of being a replacement (various bolts still have paint on them showing no sign of a wrench ever having turned them, all the clips and looms are present and in the proper location which they almost never are if a mechanic had done an engine replacement, etc, etc.)

Regarding the picture of your 1990 vintage cam..... I'm wondering if 91-92 motors aren't slightly different. The dowel on my 92 cam is longer and I notice that you even made note that your cam has the shorter-style dowel. Maybe we've figured out the cut-off year for cams with/without a fuel pump eccentric.

 

I honestly can't say. I note the shorter dowel pin only in relation to Gen II roller cams. That pic was used for other purposes. I am unaware of the dowel length on other years. Well, I geuss if you guys have old cams laying around we could probably get a good idea. Everyone to your garage and report back.

 

another bad pic by me. just flat all the way around, no lobe

 

Red- yeah, that's exactly what mine looks like out of the 92.