My New TSP Sleeper 482 Stroker Motor

And duration@ .050......the valve will get to .050 sooner......it won't effect seat to seat number

 

Since the lift on my roller is already .590 intake & .565 exhaust, I think I'll stay with the 1.6 roller rockers. The duration on the cam is 230/244 on a 112 LC installed 6 deg advanced. It's also a 4/7 swap (firing order).

 

I wondered the same thing myself. I'd like to hear Jim's comments on geometry.

 

The contact location of the BBB with stock rockers is wide across the tip of the valve, unlike what your use to seeing with a roller rocker, which has a very small contact area in comparison. The wear marks seen here don't indicate a geometry issue, in fact just the opposite is true with aluminum heads. The rocker towers on those heads are .100 taller than the iron heads. This helps the geometry. These heads are new, so there is no issue with tip height, it's well within specs.

The taller rocker pedestal helps because the rocker geometry of a BBB is fixed, due to it's pedestal mounted shaft rockers. The fulcrum point must be changed to move the contact of the rocker pad or roller/valve tip.

The damage to the outside of the a couple valves is the result of the the jagged edge of a broken off steel valve pad being drug across that valve tip for an extended period. Ray says he drove it 300 miles since the nationals.

That's not the real cause tho...

The real cause is because I am too nice a guy.. When I saw the damage to every rocker on the driver side, I knew that the single rocker breakage due to a bad casting rabbit hole we had been going down was not the cause for failure. This was something that happened, to the whole engine, after it left my shop. Remember, I worked this thing about 3x as hard as I do the typical engine. The dyno stresses these engines much more than the car ever will. Valvetrain issues, assembly problems and system wide deficiencies are uncovered during this process. Those rocker tips were in perfect condition after the dyno sessions.

But the carnage I was looking at when I saw the rest of the rockers on that driver side shaft, was clearly the sign of something really bad happening, and to convince yourself that it's only happening on one side is silly. One would expect the passenger side to look exactly the same.

I knew that, which is why I told him to take it home and pull it apart to inspect it. I just wasn't as forceful about it as I should have been.

We were at the GS nats, it was Saturday, right before elimination.. and I didn't want to pull the AC compressor off and all that stuff apart to get the passenger side cover off. I did not want to ruin Ray's weekend at the Nats. As it turned out, he missed his call, and did not run it again.

I should have stressed vigorously to him that it needs to come apart as soon as he got home.. but I was going in about 8 different directions that day, trying to track down all the customers I had to pick up and deliver parts to/from, in the 3 hours I was at the event.

That was a mistake on my part.. had I insisted on pulling that passenger side cover, we would have fixed that side with the used rockers that he had, he would have went home and not driven it hard till he fixed his fuel system...

And we are not having this discussion right now....

How am I so sure?

Because he drove the car for 300 miles, after the driver side rockers were replaced, but drove it in a manner that it never leaned out, never detonated, and there was no damage at all to the driver side rockers. You combine that with my experiences on the dyno, where it was never dangerously lean, and common sense dictates that detonation is the issue here.

A rocker arm does not care if your beating on it, rpm is not a factor unless you have valvetrain instability or harmonics. it goes thru the basically the same stresses at 5000 rpm, that it does at 500.

But driving it hard, certainly does influence greatly the propensity for the engine to detonate.

Now, the good news is that the roller rockers have a completely different contact width/location on the valve, it's in the center, and it's nearly certain that it will avoid the damaged area of the valve tip of that one valve. That is the main reason I recommended that the best course of action was switching to the roller rockers that are now available.

JW

PS..

I have a set of $1200 bushing equipped roller lifters, that came out of a motor that was detonating in the shop here.. They are beat up...several of the rollers (both intake and exhaust) barely rotate anymore. This is a combo that lasted for hundreds of passes, before we made a change to the motor that caused it to detonate. That motor broke two pistons, and scorched those lifters, in 2 pulls on the dyno, and two passes on the racetrack. The over-pressurization of the cylinders that detonation causes affects the entire engine, not just the bottom end.

 

Thanks, for weighing in, Jim. Didn't mean to put you on the spot. If I'd known how easy it is to work on the passenger side, even with the compressor mounted, I'd have suggested that we use the other 430 rocker assembly we bought at the swap meet and take care of that side as well. It wouldn't have changed me being able to race on Saturday but it would probably have saved the broken rocker on the #2 cylinder back home. But, maybe that was a blessing in disguise as it allowed me to make the decision to go with rollers and be done with the issue.

By the way, here's a look at the passenger side with the compressor still mounted. Just the top support bracket needed to be removed which was just three bolts and loosen the two large mounting bolts and swing the compressor away. I've heard that some actually leave this top bracket off.

 

Hey Jim just put of curiosity,, were the bearings beat up as well?? My friends motor having some similar issues with lifters, but bearings always look great?? Wouldnt detonation be present in bearings first ?

 

Nice Ray... Im making the plunge on the same build... I'll be picking up fresh blue block and crank next week.... I got a set SE st1 bare casting on order... I was wondering what valves are in your heads? Thank you...

 

I know a guy with a 1974, 318/2bbl Challenger that sez he can take you...

 

No surprise here. Is he one of those Stock Appearing Drag Racing guys?

 

Yeah! I think it was Ned, or Neal, or Nixon, or Nash... something like that...

 

Some of those guys are running crazy cubic inches and 13-14:1 compression. Amazing what they can get out of those motors.

 

Yeah. A well designed and properly assembled small block build can make some impressive power. (but I was just being silly to Bob )