Stage II powerplant with Fiero umbrella

[fog]

So, the weekend ended for me before it started. Oil pressure dropped to almost zero and now I pulled the engine.

crank has damage on #4 rod
#4 rod has heat spot, but measured out OK.
Oil pump gears are damaged.

So I would say, something had to fall to the engine during assembly.

Now, the crank is already 20/20 and I get the new sizes from the machine shop tomorrow on the day after, then I need to order the bearings.

Right now, there were TRW bearings all around, but I would like to use something else. Suggestions?

From the other beast, read in the Stage II section. that part of the weekend was a complete success.

 

[WIKEDV6]

I am so sorry to hear about the bad news but I like your spirit. You may want ask the guys over at stage II tech about the bearings. What kind of crank? wide or narrow journal? My stage II build, I had the machine shop order coated bearings and I am not sure what brand they were but it was expensive. I have a 3.59 BMS wide journal crank in mine.

Prasad

 

[fog]

I am so sorry to hear about the bad news but I like your spirit. You may want ask the guys over at stage II tech about the bearings. What kind of crank? wide or narrow journal? My stage II build, I had the machine shop order coated bearings and I am not sure what brand they were but it was expensive. I have a 3.59 BMS wide journal crank in mine.

Prasad

BMS 3.625 20/20 under at the moment. Wide journal.
Last time I used TRW(Clevite) 3800 SC rod bearings, since those are wider than 3.8 but pins are the same.

 

[fog]

New event and new personal best.
10.61 @ 131
and after tuning but no traction:
10.9 @ 144.8

...and then the timing chain let go


Boost was @ 20psi both runs, first AF was 8:1 thanks to the ethanol injection, second one I leaned it out 20% but still O2 correction sat at -15% and 10.5:1
The trans shifted at 5700 both shifts on the first run and on the second run I held it to 6800 at the 2-3. (can't control 1-2 manually).

I'm trying to tear it apart right now to get the part orders in. Then I can relax a week while those are in transit.

 

[S10xGN]

Awesome trap speed! Hope for the best with the timing chain...

 

[WIKEDV6]

Almost 145mph....Wow...just Wow. What's scary is you have plety left in it. Are you running pump gas and Alky or race gas?

Prasad

 

[fog]

I'm running pure ethanol with ethanol injection. the AF-s are "gasoline" numbers, since I feel more comfortable using those instead of lamda or ethanol ones.

I need to source some spare valves and maybe seats for the GN1-R heads now but where to get those?

Also, what timing set would be good, the original type does not work, cam gear is pre-86 one?

I need to start ordering parts asap, but cant access the car till next week.

 

[Street Lethal]

Any fan of DJ Tiesto.... is a friend to me! :biggrin:

Awesome cars....

 

[fog]

The news is 3 intake valves, 1 exhaust valve, chain, 2 sprockets. And I have a deal pending in Cottons to get all. If everything works out fine, I'll be on the track in 10 days. Hope to get to nines.

 

[WIKEDV6]

Did you try calling Champion Direct? Maybe for future use . You need to talk to Tom. (386)-446-4488.
Wow was it a double roller chain? what was the seat pressure on the springs? Hydrualic or solid roller cam?

Prasad

 

[fog]

Did you try calling Champion Direct? Maybe for future use . You need to talk to Tom. (386)-446-4488.
Wow was it a double roller chain? what was the seat pressure on the springs? Hydrualic or solid roller cam?

Prasad

The international shipping is dead expensive, so from one place, it will be cheaper. So I contacted a vendor that has Champion and TA parts available.

Yes it was a double roller, and it had been pulled off and pushed on 6-7 times, so I think it was damaged during one of those pulls.

I dunno about the seat pressure and such. Solid roller 212/212 precision cam.

 

[fog]

Well, got back from the vacation and teared some more apart...

The cause is obvious, the chain had eaten to #1 main front face and thanks to the slop and converter pushing the crank outward, it finally tried to ride on the main. And bang!

This is BMS crank witch should not have this issue, only Crower according to my knowledge had this issue.

What can I do about it without taking the crank out?
a) Shim the sprocket a little further down the snout?
b) Grind the face with dremel?
c) Put in new set and pray?
d) ?

 

[CTX-SLPR]

Well, got back from the vacation and teared some more apart...

The cause is obvious, the chain had eaten to #1 main front face and thanks to the slop and converter pushing the crank outward, it finally tried to ride on the main. And bang!

This is BMS crank witch should not have this issue, only Crower according to my knowledge had this issue.

What can I do about it without taking the crank out?
a) Shim the sprocket a little further down the snout?
b) Grind the face with dremel?
c) Put in new set and pray?
d) ?

What's your crank thrust run out, cam thrust, and how's the chain alignment between the crank and the cam? Sounds like the oil pump might be trying to drag the cam backwards and the chain is pulling the crank with it (100% theoretical guess). I'd check the thrust bearing to see if you've worn it down too.

No expert or experience, just thinking about the mechanics of it.

 

[fog]

The problem was that the cam was buttoned with torrington bearing but crank can move as much as thrust bearing allows. That angled the chain and it started to ride on the main. Loose chain paid a key role in this also.
I got new chain, repaired the heads and now the engine runs again. That can't be said to the cv-axles. I spooled up 8psi on the start, smoked and when tires finally gripped at 20 foot and 15psi, the cv-axles snapped.

Luckily for me, the event was a wash-out, so I did not fall behind on the points.