It looks like those aftermarket rockers may have too big balls for pushrods. We had cracked ball cups and after then bended pushrods.

Your cups looks to be fine, so I think you got no same problem.





Very nice torque btw!



When you move your max torque rpm from 4000 to 5500+, you can get even more hp's.



Whats your intake air temp? With dragster there was stock plugs with same boost levels and with no problems.



Can we a see a first 1000+ftlb with 20psi.



Hyvinkää, FI

Hutz, we really don't know for sure, but first problems were caused by loose adjusting nuts and too wide adjusting balls on rockers. When the push rods cracked due too large balls, adjustment of the valves got loose and let the push rods to drop. Those are not affected by boost. The last problem was odd, because when Jyrki came back from that 10.020 run, the engine idled correctly. But, after we fired it again after about half an hour it run with only 7 cylinders and when we opened the covers, #5 had no push rods and they were badly bent after we found them from lifter valley later.

Last weekend we run six 1/8 mile runs without any problems. But, we had only 10 psi of boost as we had on the dyno earlier this summer and those Fel-Pro blue gaskets are still holding ok.

 Seppo from Järvenpää, Finland
www.hollowheads.net (just click the hole in the head to proceed)

Any chance the cylinder was under pressure and hydraulic'd? Chuck

Y's guys rule!
Looking for McCullouch VS57 brackets and parts. Also looking for 28 Chrysler series 72 parts. And early Hemi parts.

MoonShadow, 292 w/McCulloch, 28 Chrysler Roadster, 354 Hemi)
Manchester, New Hampshire

If an engine is built correctly for it and uses the right fuel, there's no reason it won't. The most significant problem problem with a Y is that it is a stock block and I'm sure the engineers did not plan for 6, 7, 800 ftlbs or whatever and the associated cylinder pressures you may reach. The Y has proven to be quite strong when compared to other oem engines of similar displacement but you may find the limit. I sincerely hope for the best but I advise you to expect and be prepared for the worst. If you're not, then don't do it.


Lawrenceville, GA

Moonshadow, that's what we consider as a reason too. And, someone has to discover the limits, so Hutz, we are keeping the thumbs up for you and your experiments. It's very highly possible, that we will also raise our boost level at the next race and we hope we don't break anything .

 Seppo from Järvenpää, Finland
www.hollowheads.net (just click the hole in the head to proceed)

I think you are correct in basic theory Charlie but there are examples that seem to indicate the Y, if correctly prepped, will take a lot of boost. My new block was in a boat with a 6v-71 GMC supercharger on it. Ted can possibly shed some light on this.
As far as the twin turbo is concerned I just wondered if there was a shot of fuel or something that would hold back the piston on restart and cause the two bent push rods. Perhaps the piston to wall clearence needs opened up a bit. The extra heat that is generated after a hard pass and shut down could cause expansion of the piston slug causing it to drag in the block. They say it ran fine all the way through and on the way back. It was on a later restart that the miss developed.
Of course you know I'm no expert and not really that informed about these things. All I can do is recall the past and theorize the cause. I just want to see some 9's and maybe 8's out of this awesome rig. Chuck

Y's guys rule!
Looking for McCullouch VS57 brackets and parts. Also looking for 28 Chrysler series 72 parts. And early Hemi parts.

MoonShadow, 292 w/McCulloch, 28 Chrysler Roadster, 354 Hemi)
Manchester, New Hampshire

HollowHead,

While replying to Charlie I recalled a situation with piston clearence being to tight and causing the piston to drag in the hole after shut down. When you make a hard pass and go straight back to the pits and shut the engine off the heat will build some. Just a thought. When I was in Hawaii I helped out a fellow with a 71 Firebird running an Oldsmobile engine. Basicly a Super Stock car. After a pass we had a quick disconnect water inlet on the block and carried a water tank with a 12V electric pump in the chase vehicle. Once connected the radiator drain was opened. As we towed the car back to the pits the hot water ran out and was replaced with cooler water. We never had a problem with the pistons again and were on top for quick turn arounds during eliminations. We always started with a cool block. Just a thought, I'm sure the Twin Turbo's make some heat. Chuck

Y's guys rule!
Looking for McCullouch VS57 brackets and parts. Also looking for 28 Chrysler series 72 parts. And early Hemi parts.

MoonShadow, 292 w/McCulloch, 28 Chrysler Roadster, 354 Hemi)
Manchester, New Hampshire

I am starting to think that John might be right about my problem with the bent push rod.  This problem did not start until I switched my spark plugs.  The first set of plugs I was using I would have this problem when I wasn't even under boost.  It would act up at about 3,000 rpm in vacuum.  Now I could run the engine all day at 3-6,000 rpm and engine would run very smooth and content.  I didn't have this problem until after a few dyno runs at 12 lbs of boost.  I think I am going to go with a 8 heat range ngk plug and see what happens.  I am confident about 20 psi.  The engine is built with the best parts and I as long as I keep my tune and afr at the right specs I don't see and parts breaking with 500-600 wheel horse power, which is were I am hoping to be at 20 psi.  Don't worry the y-block world will be the first ones to know when I hit that mark or SCATTER my engine trying!!!!  No worries it's just a bunch of iron when it comes down to it.  (and a little money too) but that's PAPER!!  LIVE FOR NOTHING OR DIE FOR SOMETHING.  (STALLONE)

I like your attitude, Hutz! Keep going .

 Seppo from Järvenpää, Finland
www.hollowheads.net (just click the hole in the head to proceed)

There is some good info about spark plugs and heat ranges here

http://www.championsparkplugs.com/charglossary.asp?kw=Heat+range

As, we have had Champion RF14YC plugs now and when we took those of, they were very close to be melted if those pictures are exact . So, we will definetely move to colder plugs but that means that we have to start the engine with hotter ones due E85 fuel and that we don't have any cold start enrichments. Then, after engine is warm, we can change to colder ones

 Seppo from Järvenpää, Finland
www.hollowheads.net (just click the hole in the head to proceed)