350 over.rev

[Stinky]

I have the Suburban set to move something heavy....it is in low.range.

I go in side and the son says, can I drive the Sub in to town....yes.  3-5 secs later I go and try to catch him and see it turning on to the road.

5 minutes later, he calls and says that he is broke down.  It started losing power (cuz it wouldn't rev anymore).

He was trying to do the speed.limit (65), or more, in low.range.

It now has a roller.cam block w.Mercruiser heads.

2 holes in the pan, notice the rod and the other bent stuff.

 

[Bobalos]

Wasn't the thing screaming???  

 

[KLC]

When did this happen? In 1985? That engine hasn't had oil in it or a pan on it in years. The oil filter boss and engine mount bolt holes are rusty. Seems fishy to me sir.

 

[Stinky]

I happened about a year ago.

The Suburban went to the dunes w/a Vortec truck motor in it last year.

I just pulled those heads off an put the boat heads.  It moved again in August...maybe.

 

[LegitDuner]

I happened about a year ago.

The Suburban went to the dunes w/a Vortec truck motor in it last year.

I just pulled those heads off an put the boat heads.  It moved again in August...maybe.

I don't recall the heads being anything different? It was all about the boat camshaft. Are they special?

 

[Rorschach]

Editing my short bus comment.

My kids have done things that made wonder why they weren't riding it

 

[Stinky]

From what my machinist said, and the net backs it up, the Mercruiser have a hump in the runner or port, that induces swirl into the chamber.  They have more bottom end than Vortec heads....there is a big dif.  At about 3,500-4,000 rpm they start choking it down and it runs out of RPM.  Whereas, VORTEC heads really start to run at those RPMs, and the motor would turn more RPM.

W/Vortec heads, it wouldn't really start to run until about 20mph and would really, really run above 25mph.

W/the Mercruiser heads, at about 25mph, it is running out of steam.  But, it got 16 and 15.1 on the 1st trip after switching heads and it towed better.

CN  14102193....I think.

Stock Roller-cams have slightly less left and duration, I think.  But, it has more duration at peak lift because the valves can open and close faster w/less strain on the lifter.

I had a blown headgasket and wasn't happy w/the way the motor pulled below 15mph.