Need some advice on this one.

Using Brodix -12 15 degree heads with Jesel shaft rocker setup having offset intake rockers centered exhaust, Isky roller lifter with .150 offsets on the intakes.

Brodix and Jesel claim we have the correct parts for out setup too.

The pushrods, especially on the exhaust, are way out of alignment. I haven't devised a way yet to actually measure how much, but from eyeballing them, some look to be more than 20 degrees from perpendicular.

MONTY graciously agreed to post a few of the pics we took of the pushrods and he posted them on his site: HTTP://montygwilliams.com/IMG_0001.jpg
0002.jpg 0005.jpg 0006.jpg and 0009.jpg

Take a look when you get a chance and give me your thoughts on this alignment concerns.

Jesel says the alignment shouldn't be off by more than 3 (three) degrees and Brodix claims never to have seen an exhaust pushrod alignment problem before.

I'm stumped.

Thanks,

Jake

 

Are the arms shimable on the shafts ? They look like a similar setup to the T+D's on my Buick that can be shimmed side to side.

 

Jake,

I figured you guys obviously have everything right, like you said, there's only one way to install the rockers and lifters. Just trying to eliminate the basics. My shaft rockers and lifter are the same way - fool proof. After a long day in the garage, and a coupla' beers, I need it that way....

I still think your setup is within the range. I know you said you think some are off as much as 20 degrees, but 20 degrees would be pointing at around the 1:30 postion, I don't see that in the pictures. Keep in mind that the lifters that are on the lobe, sticking farther out of the lifter bore, are oging to have a temporarily steeper angle than those lifters that are on the base circle of the cam.

I'll look to see if I have any pics of my pushrods installed, with the intake off. The only difference between my 18* heads, and the 15* heads is the valve angle. It should be the same....

Just to be sure everyone see's the pics...








[Modified by Monty, 7:10 PM 7/2/2002]


[Modified by Monty, 7:25 PM 7/2/2002]

 

Why not send the pictures to Jessell?

 

We did, and to Brodix too, but no response as yet.

Thanks for all your help, Monty. I plan on playing with this problem some more later today. I hope to get better photos with the engine level on the stand and the camera held square.

Another problem is that the Isky lifters only come in centered, .100 and .150, which limits how much adjustment we can make by just using lifters. We may have to end up using a combination of offset exhaust rockers (currently they are centered) and offset lifters.

I'll keep everyone posted.

Jake

 

Jake - to me those don't look that far out of alignment. That's real race car stuff and when ever you get into the extremely large intake valves (2.15-2.25) in small bock Chevy's or the altered valve position heads your going to have angular displacement issues.

Is that 415 ci motor with the Brodix heads for your Vette? What was the reason for not just getting Jesel rockers.

 

They are Jesel rockers; their entire shaft rocker setup supposedly specifically for the heads we're running.

The engine is a 434 for Steve's 86 Vette. BowTie block, 6" Carrillos, JE pistons, internally balanced 4" stroke forged crank, etc.

Steve went with Isky roller lifters because they are the only ones that work with the BowTie block's tall lifter bores AND allow the use of a rev kit.

Spent most of yesterday trying different offset lifters (centered, .100 and .150) and got them a lot closer to perpendicular.

I ended up using .150 offsets on both the intakes and the exhausts. .150 lefts on #1, .150 rights on #3, .150 lefts on #5 and .150 right on #7.

I sent Monty the latest pics.

Brodix said they have never seen their head needing an offset on the exhaust, but Jesel said "Oh, No! We've seen it!"

Go figure.

I drew up a circular graph and degreed it in 5 degree increments. I then drew a perpendicular line 6.800 inches in length to represent the length of the pushrod we're using. I then drew another 6.800 line 3 degrees off from perpendicular just to get a visual representation of what 3 degrees is. Man, it "ain't" much!!!!!

Jake


[Modified by JAKE, 5:16 PM 7/4/2002]

 

Well, I've gone about as far as I can go on this issue and here's the result.

Both the intakes and exhausts need to be off set .150 to straighten the pushrods as best they can without having to resort to some unacceptable head mods.

Actually, the intakes could stand an additional .050 to make them offset a total of .200, but that would involve the intake pushrod entering the intake port, necessitating the installation of a tube to seal the port. This would disrupt airflow and create the REAL probability of a vacuum leak. So .150 is the max.

In order to move the intake pushrods .200, I'd have to grind on the head near the intake ports for clearance and this would break into the intake port, otherwise the pushrod would rub on the head.

Now, how to get that much offset.

Since the Isky tall, roller lifters only come in three configurations -
Centered; .100 and .150, my options are very limited.

After playing with all three versions, I found that using the Isky .150 gets the best result, all things considered. Problem is, this would call for Steve to buy an additional eight .150 offset lifters; leaving us with eight centered lifters that cannot be used in this engine.

As I said before, no other lifter company sells lifters that meet all our requirements: allow the use of a rev kit, are much taller in order to fit the BowTie block's tall lifter bores and have the offsets we need.

Then we struck on the idea of having JESEL change the intake rockers from centered to .150 offset. This would have been the best of ALL worlds: It would have offset the pushrod the needed amount, allowed us to NOT have to buy eight new lifters AND would allow the rev kit we already have to fit with no spring alignment problem.

Called JESEL and, as you might expect, they can't offset the intake rockers that much. They can only offset the intakes for our specific heads .080, which "ain't" nearly enough.

JESEL said that most guys just run them "crooked", but since we've gone this far already, why start cutting corners now. So it's back to buying eight .150 lifters. There's the issue of parallex error when running non-perpendicular pushrods, which impacts valve lift and, to a lesser extent, camshaft duration.

Here's how it shakes out"

#1 LEFT offset
#3 RIGHT offset
#5 LEFT offset
#7 RIGHT offset

#2 RIGHT offset
#4 LEFT offset
#6 RIGHT offset
#8 LEFT offset

Both intakes and exhausts being offset .150 in the direction indicated.

I did a mock up using only .150 offsets and Steve took some pics of how much straighter the pushrods are using only .150s. If anyone's interested, I can email them; they're in a BMP format.

So one more hurdle had been crossed, now we've got hose routing and wiring to contend with.

Jake