Null


540" BBC Build questions

  • 34 Replies
  • 9988 Views

Beaveretriever

  • Join Date: May 2008
  • Location: Fullerton, Ca
  • *
  • SCJB Plus Member
  • Macho Member
  • ********
  • Posts: 2,752
  • Karma: +34/-0
    • View Profile
  • Liked:
  • Likes Given: 87
« Reply #25 on: January 15, 2014, 04:25:41 PM »
It's not "too big", it's just hard to see going out that far leaving one more possible bore left on a new block... that's just me though... I'm cheap and like being able to get several builds out of parts. Pistons are really not that expensive... you can get a set of small SRP domes or even flat tops for your combo fairly reasonable... so, in my opinion, the JE's would have to be a screaming deal to settle on using a less than common rod and going all the way out to 4.600.

.020 in the hole is really not a big deal since you can just have the block decked to whatever height you want... and seeing that you want to go about 10:1 on an iron head... you're gonna need a tight quench. Here's the thing... 10:1 on an iron head is fine... actually, I've gone as much as 10.4:1 without issues at 34* timing, but if you go aluminum, then you'll be leaving some compression and power on the table... I've run just over 11:1 with no problems on aluminum heads cammed correctly and with a nice tight quench... that was my point of making a plan before you start snatching up parts. As far as "fake compression"... I have no idea what your getting at. The Darts and Brodix are a much better cylinder head... actually I prefer the Darts and really like the Edelbrock Victors as a nice lots of bang for the buck head.... back to the point... so besides from a compression standpoint, the port design, and the fact that they are a shit ton lighter, they offer a better starting point, and have greater potential worked over... but again, if you have merlins, plan on running the merlins, then build accordingly and run the merlins... if you plan on running aluminum, then build accordingly and run them.

What I meant by "fake compression" is cylinder pressure that you can build with a cam. Like you said 11:1 cammed correctly.

I appreciate the advise. Like Danny said this isnt pb. Different people different attitude here. I will put something together on paper and pick your brain some more. Thanks bostick

Sent from my SAMSUNG-SGH-I747 using SoCal JetBoats mobile app

  • Boat #1: 1981 Eliminator Daytona 19' Jet
  • Boat #2: 2003 22' Placecraft Deck boat



Six-Oh-Nine

  • Join Date: Jan 2014
  • Location: El Cajon, Ca.
  • *
  • Sr. Member
  • ****
  • Posts: 439
  • Karma: +26/-0
  • Registered User
    • View Profile
  • Liked:
  • Likes Given: 0
« Reply #26 on: January 15, 2014, 07:18:27 PM »
This isn't pb. This is place is about people helping people without panties getting in a wad. I heard it as you giving us some damn good tech a voicing your opinion.  :beer:

I like to offer advice the best I can as to get the best bang for the buck and get people headed straight in the direction they want to go, rather the long, costly, roundabout way. :banghead:

Kinda on the topic... but not really at all...

I've backed way off giving unsolicited advice there. Not always, but a good amount of the time, you offer an opinion and it is guaranteed to be "the wrong opinion"... and people are more than happy to let you know that your opinions are "wrong". Over there... a 18' Tahiti that is someone's first boat and just looking to get to the sandbar, have some beers, and perhaps tube behind, will be told they MUST have a full race pump, blueprinted bottom by a professional, and a full tilt all forged, all roller, race built motor.

I still dig a lot of the folks, still will gladly participate, but I've noticed a little different vibe.
The Bostick

Some people play hard to get, I play hard to want.

Six-Oh-Nine

  • Join Date: Jan 2014
  • Location: El Cajon, Ca.
  • *
  • Sr. Member
  • ****
  • Posts: 439
  • Karma: +26/-0
  • Registered User
    • View Profile
  • Liked:
  • Likes Given: 0
« Reply #27 on: January 15, 2014, 07:20:10 PM »
What I meant by "fake compression" is cylinder pressure that you can build with a cam. Like you said 11:1 cammed correctly.

I appreciate the advise. Like Danny said this isnt pb. Different people different attitude here. I will put something together on paper and pick your brain some more. Thanks bostick

Sent from my SAMSUNG-SGH-I747 using SoCal JetBoats mobile app

No problem guy.
The Bostick

Some people play hard to get, I play hard to want.

Flusher

  • Join Date: Sep 2011
  • Location: Colton, CA
  • *
  • Macho Member
  • ******
  • Posts: 2,109
  • Karma: +79/-0
  • The Machinist
    • View Profile
  • Liked:
  • Likes Given: 26
« Reply #28 on: January 15, 2014, 08:41:35 PM »
Hi six-oh-nine,

Great posts.  What quench clearance do you like to see?

Thanks in advance,

 Joe

Sent from my DROID RAZR using SoCal JetBoats mobile app

"I want to roll with my brother Joe" - Joe Bateman - January 29, 1950 ~ November 27, 2013

lupo1904

  • Join Date: Jun 2010
  • Location: santucky
  • *
  • Hero Member
  • *****
  • Posts: 1,189
  • Karma: +9/-0
  • jet boat life
    • View Profile
  • Liked:
  • Likes Given: 0
« Reply #29 on: January 15, 2014, 10:03:38 PM »

Btw... sorry if I seem like a dick and being negative on your build... that is not my intention.
your dog is a DICK


Sent from my iPhone using SoCalJetBoats

Sicaz66

  • Join Date: Sep 2012
  • Location: Lakeside
  • *
  • Full Member
  • ***
  • Posts: 231
  • Karma: +0/-0
  • Registered User
    • View Profile
  • Liked:
  • Likes Given: 14
« Reply #30 on: January 15, 2014, 11:41:40 PM »
What kind of compression you trying to go with? What heads? Figure out what you want instead of buying something because you got a deal on it. Typically, I like to stick to common size shelf items like pistons and rods whenever possible... (6.535 or 6.700 or 6.800 in the instances of a tall deck) there is such a great diversity of parts available that there is no need, in most cases, for custom, and makes for the ability to get exactly what you want. Also... it seems damn near a sin to mow a brand new block all the way out towards it's outer limits the first go around. Unless you have a particular cubic inch limit class you're trying to build and eek out every last bit of power, it's nice to allow yourself a few bores/rebuilds. I haven't seen much difference (albeit quite slight) between let's say 4.560 and 4.600 bores... but the 4.560 will allow for several bores left in the block.

Seeing that you are expecting this to be built over a period of time, create a game plan on exactly what you want to build, and then just pick up parts as you come across exactly what you want as you can afford them. I'd say that easily half the people I build engines for can't really afford exactly what they want right then and there... most of us, and I'm sure your in this boat as well, have to work for a living and pay bills and building a jetboat motor comes a little far down the priority list... 8-10-20K to drop is just not gonna happen... but the way we make it work is come up with a plan of exactly what we're gonna build, right down to a parts list, and then just start buying parts and doing work as the wallet will allow... it takes a little time (which you have)... but as long as you stick to the plan, you get exactly what you want, that will work as you want it, in a manner that you can afford.
exactly what the great bearded one relayed to me. now a couple of $ and not a whole lotta time later i will be putting a(my) dream motor in my float. all around good advice and a solid dude.
  • Boat #1: 2001 placecraft sport cruiser( laid up by rpm).
  • Boat #2: 26' Blackman billfisher,fish machine.


Null


Sicaz66

  • Join Date: Sep 2012
  • Location: Lakeside
  • *
  • Full Member
  • ***
  • Posts: 231
  • Karma: +0/-0
  • Registered User
    • View Profile
  • Liked:
  • Likes Given: 14
« Reply #31 on: January 15, 2014, 11:53:10 PM »
your dog is a DICK


Sent from my iPhone using SoCalJetBoats
and he looks like one ...with legs. FRANK will check a fool.
  • Boat #1: 2001 placecraft sport cruiser( laid up by rpm).
  • Boat #2: 26' Blackman billfisher,fish machine.

Six-Oh-Nine

  • Join Date: Jan 2014
  • Location: El Cajon, Ca.
  • *
  • Sr. Member
  • ****
  • Posts: 439
  • Karma: +26/-0
  • Registered User
    • View Profile
  • Liked:
  • Likes Given: 0
« Reply #32 on: January 16, 2014, 09:34:28 AM »
Hi six-oh-nine,

Great posts.  What quench clearance do you like to see?

Thanks in advance,

 Joe

Sent from my DROID RAZR using SoCal JetBoats mobile app

Bore size, clearance, and application will dictate some variants in desired quench... but a general rule on a typical aspirated deal, .040-.045ish.
The Bostick

Some people play hard to get, I play hard to want.

Beaveretriever

  • Join Date: May 2008
  • Location: Fullerton, Ca
  • *
  • SCJB Plus Member
  • Macho Member
  • ********
  • Posts: 2,752
  • Karma: +34/-0
    • View Profile
  • Liked:
  • Likes Given: 87
« Reply #33 on: January 16, 2014, 11:37:58 AM »
Bore size, clearance, and application will dictate some variants in desired quench... but a general rule on a typical aspirated deal, .040-.045ish.

When you talk about quench are you talking about the head gasket being smashed? I know that's not the right term but like I said I'm a volkswagen guy and we don't use head gaskets 

Sent from my SAMSUNG-SGH-I747 using SoCal JetBoats mobile app

  • Boat #1: 1981 Eliminator Daytona 19' Jet
  • Boat #2: 2003 22' Placecraft Deck boat

Six-Oh-Nine

  • Join Date: Jan 2014
  • Location: El Cajon, Ca.
  • *
  • Sr. Member
  • ****
  • Posts: 439
  • Karma: +26/-0
  • Registered User
    • View Profile
  • Liked:
  • Likes Given: 0
« Reply #34 on: January 16, 2014, 12:24:52 PM »
The quench is the distance between the head and piston... so how far in the hole (+) or out of the hole (-) the piston is from the deck surface, plus the compressed gasket thickness. So a piston .005 in the hole, plus a .041 thick gasket would be .046. Or a piston out of the hole .003, plus a .041 gasket would be (-.003+.041) .038.

Ahhh Volkswagens... I done my time with those things... got over that sickness for the most part. Hahaha!
The Bostick

Some people play hard to get, I play hard to want.


Null


 


Website Security Test
Powered by EzPortal

Null

Website Security Test