Go Back  Offshoreonly.com > Owners Forum > Formula
311 Engine Upgrades >

311 Engine Upgrades

Notices

311 Engine Upgrades

Old 11-02-2020, 10:56 AM
  #81  
VIP Member
VIP Member
Thread Starter
 
TomZ's Avatar
 
Join Date: Feb 2001
Location: Virginia Beach, VA
Posts: 2,559
Received 206 Likes on 150 Posts
Default

Originally Posted by TylerBurich View Post
Tom, did you decide on lifters yet or did I miss that part?
Tyler, Iím using Crane long-body lifters that work with the factory dog-bone guides and retainer.
TomZ is offline  
The following users liked this post:
TylerBurich (11-02-2020)
Old 11-17-2020, 12:10 PM
  #82  
VIP Member
VIP Member
Thread Starter
 
TomZ's Avatar
 
Join Date: Feb 2001
Location: Virginia Beach, VA
Posts: 2,559
Received 206 Likes on 150 Posts
Default

No real updates to share... just waiting on some parts to come in. Machine shop is a little slow, too.

Just keeping the thread up-top.

TomZ is offline  
The following users liked this post:
TylerBurich (11-17-2020)
Old 01-04-2021, 06:57 PM
  #83  
VIP Member
VIP Member
Thread Starter
 
TomZ's Avatar
 
Join Date: Feb 2001
Location: Virginia Beach, VA
Posts: 2,559
Received 206 Likes on 150 Posts
Default

Some updates...

One short block is together. .030 over with factory crank, Eagle rods, and 4.50 SRP pistons that are .012 in the hole. The other block is at the shop getting the same treatment.

I changed direction with the cams. I sold the 500 EFI cams and picked up a set of hydraulic rollers that Rookie had for sale. 235/241 @ 050, 647/647. These will be a better match for my AFR heads vs the 500 EFI cams

Heads... kind of a mess but getting through it. I got a very good deal on them, but finding that they really do need a good amount of work. Iím replacing exhaust seats on both sets, and to clean up the decks, theyíll probably need to shrink down to 112 cc chambers. Ouch. I was hoping that I wouldnít have to go that far, but theyíve been decked before (one set measures at 114 cc and the other 115cc). Compression will come in between 9.3/9.4 using a .039 gasket. I think weíre still doable with 87/89 at this point, though honestly Iíve contemplated selling these and buying a set of EQs so I could avoid the complexity of closed cooling. Oh well, itís only money and this is what I love doing. Theyíre going to be beasts when done.

In other news.... steadily making progress on the Bullet. One engine is wired with the other not too far behind. Iím waiting on some fuel fittings that were backordered to come in and need to wire the ignition boxes. The wiring harnesses for the boxes will done using weather-pack connects so those will
be nice. And the hydraulic steering made it in over Christmas.

Iím not sure my neighbors appreciated having a boatyard on their street... so far no one has complained. That might change when the Bullet gets fired up!

Hope everyone is getting a nice start on the new year.
TomZ is offline  
The following users liked this post:
TylerBurich (01-05-2021)
Old 01-05-2021, 08:26 AM
  #84  
Registered
 
Join Date: Mar 2019
Posts: 622
Likes: 0
Received 94 Likes on 61 Posts
Default

I wish we lived loser, I would love to learn/watch/help with this project.
Tom B.
F14A water jet is offline  
Old 01-06-2021, 10:01 AM
  #85  
Registered
 
Join Date: Jul 2006
Location: Charleston, il
Posts: 781
Received 13 Likes on 9 Posts
Default

What amount of quench are you shooting for? I believe if you focus on that your dynamic compression shouldn't be as much of an issue.
TylerBurich is offline  
Old 01-06-2021, 10:55 AM
  #86  
Platinum Member
Platinum Member
 
mcollinstn's Avatar
 
Join Date: Sep 2001
Location: tn
Posts: 5,655
Received 57 Likes on 40 Posts
Default

I wish I had seen this thread before your block work was done.
If your squish height (clearance between the piston quench pad and the head) was .036" to .040" you would have no trouble running 87 octane with 9.8:1 CR with a 741 cam.
Having your pistons .012 in the hole pretty much kills your ability to induce enough "quench turbulence" to benefit you unless you run .027" Cometic MLS head gaskets (since you are closed cooling, I would probably go that direction if it were me).
The difference in running .036" squish vs anything over .045" is amazing regarding how it suppresses detonation and allows you to run optimal timing with lower octane fuels. It shocks me how so many machine shops choose to ignore this fact.

Here's what I come up with on your combo.
SRP 4.500 pistons with -3cc dish
112cc heads
4.540 gasket ring diameter
.012 in the hole
.039 gasket thickness
RESULT 9.51:1 with .051 quench distance.

Here's what I recommend
.027" Cometic MLS gasket - 4.540 diam.
Same everything as above
RESULT 9.74:1 with .039 quench distance.

You will NOT regret it.
Your cam specs also point towards a need for additional compression vs the 941. It's all a bouncing ball... One thing affects all the others...

There are plenty of guys out there fighting detonation, pulling out timing, searching for higher octane in order to keep their mismatched motors happy.
Then you've got a few really happy guys out there making great power on crappy pump gas with surprising compression ratios. ALL of those guys are running "tight squish" motors.

Mopar 440's in the horrible 1970's smog era were notorious for being knock-happy with traditional hop-up modifications.
They all came from the factory with pistons almost .200 in the holes. Dropping closed-chamber heads on them to bring up compression resulted in pinging knocking turds that required race gas to make it down the road.
The other option was to put big domed pistons in them (still .050 or so in the hole) which provided another knocking pinging turd unless race gas was used.

Past handfull of years, we have been playing with RB Mopars (440's) and setting them all up with .036 squish.
We've got a 509 aluminum head stroker set up at 11.3:1 with a 265 @ 050 cam that we can't make ping with 91 octane - and it's a snappy, responsive, happy beast.
We've got a 440 aluminum head set up at 10.5:1 with a 235 @ 050 cam that is the same story - AND on 91 octane, it PREFERS the timing to be set at 20 initial, 40 total, and 58 vacuum (cruise).
Chevys are the same story - set em up TIGHT and you'll never regret it.
mcollinstn is offline  
Old 01-06-2021, 11:25 AM
  #87  
Registered
 
Join Date: Jul 2006
Location: Charleston, il
Posts: 781
Received 13 Likes on 9 Posts
Default

Smokey Yunick devotes an entire page in his book "Power Secrets" to quench. His guideline is .040" for all around performance in a 4" bore engine. Maybe add a few thou for 4.500" bore but sticking to a quench that significantly increases turbulence will greatly help with knock/pinging. I'm sure someone smarter than me will have more to add along with what mcollinstn has stated which is great info as well. Double check your piston rock and if all is well go with the .027" cometic.
TylerBurich is offline  
Old 01-06-2021, 03:13 PM
  #88  
VIP Member
VIP Member
Thread Starter
 
TomZ's Avatar
 
Join Date: Feb 2001
Location: Virginia Beach, VA
Posts: 2,559
Received 206 Likes on 150 Posts
Default

Thanks guys. I appreciate all of the advice and guidance.

I had gotten myself all wrapped around the axle regarding the heads and compression that I totally spaced on the fact that quench with the pistons still deep in the hole was going to be an issue. Interestingly, I was thinking about this last night and the light bulb was starting to go off while going through the math and looking at head gaskets.

As it comes together Iíll get it right. Iím not in any hurry to get them done and they will be right and dynoíd properly.

I need to go back and reread everything what was posted.

Again, much much appreciated!
TomZ is offline  
The following users liked this post:
TylerBurich (01-07-2021)
Old 01-08-2021, 05:22 PM
  #89  
VIP Member
VIP Member
Thread Starter
 
TomZ's Avatar
 
Join Date: Feb 2001
Location: Virginia Beach, VA
Posts: 2,559
Received 206 Likes on 150 Posts
Default

Ordered everything for the bottom end of the second short block this evening.

Iím holding off on head gaskets until I have final measurements. But I have pretty much everything else in-hand.

Cantít wait to get on the dyno to see what they do!
TomZ is offline  
Old 01-08-2021, 05:23 PM
  #90  
VIP Member
VIP Member
Thread Starter
 
TomZ's Avatar
 
Join Date: Feb 2001
Location: Virginia Beach, VA
Posts: 2,559
Received 206 Likes on 150 Posts
Default

Any guesses? My buddy Wayne is thinking 580-590. Iím thinking 625.

??

** theyíll be dynoíd with CMI spit tops, etc.
TomZ is offline  

Contact Us - Archive - Advertising - Cookie Policy - Privacy Statement - Terms of Service - Do Not Sell My Personal Information -

Copyright © 2021 MH Sub I, LLC dba Internet Brands. All rights reserved. Use of this site indicates your consent to the Terms of Use.