625 HP with the torque of a stocker at 3000 rpm

Bahhh ..... I bet the only time you sit down is at 3:49am, when you get home and sit on the padded Throne ou: :laugh:

 

Alan-- If you are doing Buicks you cannot afford a pad.


Which reminds me did you see the special on devices for the guy that has everything on TV. The throne they sell had a TV, computer, phone, fan et ect. But the thing that I thought was so unanticipated was he incorporated an excecise bike-- pedals and all into the throne. My first thought was a Wall Street customer. Down here we still use septic tanks and out houses.

 

Jim refeering to those billet main caps for that freshen up,was the block OK and it just needed caps? or did it pinch the parting line of the block itself? thanks

 

Yes, block is fine.. In layman's terms, it beats the caps off of it..

In techinical terms, what is happening is the cap is pinching in the center, even with the girdle on it.. Once it does this, you lose the register, or interference fit between the cap and the block, which is critical to maintain the housing alignment and size.

A 455 based BBB making big power is a touchy beast to begin with, so you just can't let these thing slide, or they will come back and bite you. I replaced all 5 caps on this motor, had to have the gridle re-fit, and it's ready for another line bore job.

I consider this "normal" maintainence on an engine like this.. While I know that some guys pin the caps, I see this as just tranfering the stress to another portion of the block, which can then lead to catastrophic failures, making the cost of a set of billet caps, a girdle re-fit and line bore seem like an inexpensive repair.

We will see how the billet caps hold up.. I have used them before, but never under this kind of stress.

This is the only motor we have seen this on, we have done dozens of girdle motors, up to 750 HP, and not had the cap pinching issue, so I am hesitant to automatically blame the girdle and the thinning of the main caps as the root cause of this. I believe this is just sort of the nature of the beast,once you pass 800 HP, and get near or past 7000 rpm in operating range.

Knock on wood, but this is the only issue we have had with the block on this thing, and this particular motor has been making 700+ HP since 1996. 800+ since 2002.

Of course it has a few other mods.. mainly in the oiling system.. and we have kept the RPM down around 7000, which is one secret to it's long life. While it makes the car a little slower than it could be, I believe considering the investment in a motor like this, you have to respect the limitations of the block, or you will break it, like many guys have in the past.

This is the fully assembled engine.



For this year, we have a different tunnel ram, bigger intake valves in the heads with more headwork (380 cfm now) and a bigger roller cam (283/287*@.050). The car now has fiberglass doors and rear bumper on it, and rumor has it, the one piece fiberglass front end that we have waited 2 years for, is finally on a truck on it's way to the shop.. we will see..

and this is what that motor made in it's last incarnation.. hoping for around 830 this year.



JW

 

Hey Jim,
If you see anything not right in that motor, just pack it up and send it my way. I'll be glad to take that old boat anchor off your hands. I'll even pay for the shipping.:laugh:

 

I assume this must have the halo too. Do you have a photo with it installed?

Next, do you think that the power is lifting the caps and the halo, allowing the cap-walk and pinching, or that the halo itself is distorting to allow the cap walk and pinch?

 

Nope, no halo on this one..

Had we cracked a main web, I would be putting a halo on a new block.. the halo keeps the main webs/caps from rocking forward and backward, but it's effectivness in the vertical plane, beyond what the girdle is doing, is questionable in my mind..

the forces are distorting the caps.. there was no evidence of main cap 'walk" on the block, as we often see in non-girdled motors.

I have heard that Rod Hendrickson was breaking blocks with his Supercharged motor, at the bolt holes for the mains, even with gridle in place, so there can be no question that the girdle will flex, with enough force applied to it. TA added 2 more bolts to each side of the girdle, into the block, to help alieviate this problem, and it seems to have been effective.

So in answer to your question, it's pushing the center of the cap, and the girlde, off the block, and pinching the cap in the process. On this motor, it was not a ton, just a few thousandths.. but enough to worry about. The motor was running just fine when it came apart for some upgrades and inspection.

JW

 

gotta like that block jim!!
i am ready for my 308s :TU:
i see that the stage 1se vs stage2se had very little difference
in hp/ft-lbs in the upper rpms which is good as i thought i might be missing out not using stage 2s
is that the dyno sheet that you pulled after you found those broken springs
on georges engine?

 

Andy

That sheet is from when we put the tunnel ram on the first time. Everything was fine then..


We also dynoed George's motor after we took it out of the car, before the current freshen up, to see just how much power was available still. That is when it had the broken number 7 exhaust valve spring that we did not notice, until we took it back to the shop and took it apart.

JW

 

Thanks for the insight Jim I had run into this before on the thrust cap and always kinda wondered why.

 

Hey Jim,

Its good to hear that George is having good luck with his engine.

Were you seeing any odd wear patterns on the main bearings? Is the groove in the main saddle new or was this mod done before?

I still like the idea of pinning the main caps to the block even with the girdle.

Later

 

i remember you making some dyno pulls on georges engine when i dropped off my engine, you were getting over700 hp with one basiclly dead cylinder
engine was still wild
you got the best job sometimes!!

 

Jim, what's your take on how similar the S1 SE's and S2 SE's were on the dyno sheets you provided?

 

Jim

When you do need to run a vacuum pump for the brakes.
Which one do you use? What brand? Is it electronic.
I really need one for my car but don't want to run a belt etc....


Any suggestions would be most helpful.

thanks Davido No: o No: