New Prop

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The Spook
Posts: 198
Joined: 20 Jun 2009, 15:49

Re: New Prop

Postby The Spook » 13 Nov 2016, 15:30

There is a two day event on in Taree on the 3rd and 4th of December which I have penciled into my calendar. It would appear the TAPBC has sought permission to run vintage and special interest boats at that event and it has been granted.

Should be an interesting weekend.

Bob

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bootlegger
Posts: 1472
Joined: 09 Mar 2009, 20:18

Re: New Prop

Postby bootlegger » 14 Nov 2016, 08:47

So do we have to buy a full day licence or is there some sort of deal for the vintage stuff?

The Spook
Posts: 198
Joined: 20 Jun 2009, 15:49

Re: New Prop

Postby The Spook » 14 Nov 2016, 16:49

Dave

I don't know what the deal is. I would like to think that it will be like Forster, but who knows with the APBA.

If they try to charge full fees for running a non competitive demonstration class it's only a two hour drive back to Newcastle for me. I will have at least enjoyed a cruise up the highway with the boat on the back and that's more than I've done for the last twelve months.

Bob

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loco1
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Joined: 22 Jan 2013, 22:58

Re: New Prop

Postby loco1 » 24 Nov 2016, 23:34

Bob,
PM sent.

Graham

The Spook
Posts: 198
Joined: 20 Jun 2009, 15:49

Re: New Prop

Postby The Spook » 25 Nov 2016, 00:41

Dave

I have heard that the entry for the weekend will be $100 plus a safety levy. Don't quote me, that's just what I've heard.

Apparently last year the vintage guys that attended got a fair number of runs.

Bob

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bootlegger
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Re: New Prop

Postby bootlegger » 25 Nov 2016, 08:19

Im out. I just got another massive bill from my lawyer. Ill be cleaned out again.

The Spook
Posts: 198
Joined: 20 Jun 2009, 15:49

Re: New Prop

Postby The Spook » 13 Dec 2016, 20:48

Hi guys

I've been to Taree on the 3rd and 4th of December. The boat ran well and it would appear that I have the mixtures pretty well on the money. The EGT showed around 1320 to 1335 on both days, 1350 apparently is getting too lean.

The major problem that raised its ugly head is the amount of oil coming out of the rocker covers. It was enough that on the Saturday it filled one of the catch cans and about two thirds filled the other one, spewed oil out of the one that filled up, all over me and inside the boat. Not very pleasant.

The problem appears to be complex in that these engines are designed to provide oil to hydraulic lifters and sufficient oil to lubricate the top end at 2 to 3 thousand rpm and at maybe 5000 rpm under a big rev. I have solid lifters and roller rockers which don't need that much oil and am revving the engine to 7000 rpm, so the amount of oil going to the top end is just ridiculous. Up until now no one has been able to tell me how to stop it, I also have to say that this engine is the worst one I've had for this problem. This is the first time that I've ever filled a catch can up. On the Sunday we went to 5 ltr catch cans and didn't' overflow them thankfully but put about 2.5 liters of oil in the right hand one. Thank god for 10 liter sumps.

It would appear that there is a solution, and it comes down to the size of the hole which runs through the push-rod. The standard push-rod has a .100" hole through the middle of it and this is too big so it allows too much oil to flow to the rocker gear (remember we are not feeding hydraulic lifters as well as spinning more rpm) so some smarties have come up with a solution. A 2.5mm roll pin fits perfectly inside that .100" hole and the ID of the hole in a 2.5mm roll pin when fitted is about .050" to .060", is a tap fit into the end of the push-rod and will not move once it's in there. This reduces the flow of oil through the push-rod by about 60%. The smarties have been using this trick in sprintcar engines for years to the point where now push-rod manufacturers make push-rods with these small holes so that you can buy them off the shelf. If you cant buy one with the small hole to suit your engine go to your friendly bolt shop and buy some roll pins.

It took a discussion with a mate of mine that runs a vintage sprintcar to get this information and his comment was "how come you didn't know about this trick", my comment was "you're the first person to ever mention this solution to me and I've heard just about every crackpot idea there is to solve this issue". Just goes to show that what one person considers common knowledge is another persons secret.

2.5mm roll pins are now fitted

Bob

screwit
Posts: 1063
Joined: 09 Apr 2010, 21:29
Location: Stratford vic

Re: New Prop

Postby screwit » 14 Dec 2016, 13:22

Thanks bob
This may be the fix i need
Ross

The Spook
Posts: 198
Joined: 20 Jun 2009, 15:49

Re: New Prop

Postby The Spook » 15 Dec 2016, 02:10

Ross

Just a word of warning, the hole in the end of the push-rod may not be .100" in all cases. I have been doing a bit of research and different brands may have slightly smaller or larger holes. All the push-rods that I have from crow are .100" another set which came from camtech have a slightly smaller hole which the 2.5 mm roll-pin wont fit in, but a 2 mm roll pin will. The set in the motor are crow.

However the concept sounds promising. A second thing that I am planning is to reduce the amount of oil in the sump. My sump is a ten liter setup but there is a suspicion that the stroker crank is hitting the top of the oil in the sump and splashing some of it around inside the motor, this may explain why the right catch can fills up more than the left hand one. I feel comfortable with dropping back to 7.5 liters and trying that as well at the next run of the boat. My vintage sprint car mate reckons that ten liters is unnecessary and 7.5 should be plenty. He runs his sprint car engine to 8000 rpm with 6.5 liters and it is every bit as bouncy and unsettled around the track as a hydro and they pull huge Gs in the corners. He has driven vintage hydros as well so he is familiar with how they work and what they do to engines.

Roll pins come in imperial and metric starting at 1.5 mm and going up in .5 mm increments or starting at 1/16" and going up in a variety of increments. A roll pin of the correct size should be do-able.

Bob

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bootlegger
Posts: 1472
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Re: New Prop

Postby bootlegger » 15 Dec 2016, 19:39

Bob I hope one of those restrictors dont fall out.. id be brazing them up then drilling the hole you want.
On one my 308s I ran lines from the rocker covers and ran pipes back into the sump.
I also drilled larger holes I the valley for the oil to drain back


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