Need advice on 455 build! - ClassicOldsmobile.com

Go Back  ClassicOldsmobile.com > Repair & Restoration > Engine > Big Blocks
Need advice on 455 build! >

Need advice on 455 build!

Need advice on 455 build!

Reply

 
 
 
Old November 7th, 2018, 06:20 PM
  #1  
Registered User
Thread Starter
 
Join Date: Jun 2018
Posts: 61
Need advice on 455 build!

I bought what turns out to be a pretty built 455 that I want to drop in my '68 442. Motor was built for drag racing and had 11 passes on it. I was hoping to make it more streetable by putting in a milder roller cam (already has the Harland sharp roller rocker setup). I worked with Mark (CutlassEFI) to select the custom ground cam and such and he was a gem to work with. Problem I'm starting to realize I have is that 11.5 - 1 compression cast iron heads will require much higher octane fuel than is readily available in Colorado Springs. I'm at about 7000' and my understanding is 11.5 compression is more like 10.5 up here. Before the motor is put back together and taken to the local dyno/tuning shop I need to know what my plan is for fuel. Pump gas is only 91 around here and I've seen options including dumping loads of octane booster in 91, to using E85 (blend or straight), or biting the bullet and putting aluminum heads on. To be honest I don't even know what octane fuel I need to use at a minimum but based on the compression ratio and the fact this motor will see WOT a lot, I assume I will need upwards of 100 Octane. Only place I can get the $9/gallon 100 octane fuel is quite a drive for me and I'm not sure it's worth the hassle or expense. Would love your input as I'm starting to lose sleep over this one.
teamwieland is offline  
Reply With Quote
Old November 7th, 2018, 09:43 PM
  #2  
Registered User
 
Join Date: May 2018
Posts: 139
E85/ END THREAD


You have Kum and Go gas stations all around you in Colorado springs, not like it is hard to get.

Every one of these stations has E85 for cheap and it is pretty good stuff from what friends have said and others who run hot Oldsmobiles say.

You can just step the cam down as planned and keep the high compression and buy your fuel for $2.20 a gallon..... for ~105 octane.


Buy a good E85 carburetor and install some Earl's Vapor guard fuel lines and run an electric fuel pump that is Ethanol safe and enjoy that 11.5:1 Compression!


With E85 only running $2.20 a gallon vs. $9 a gallon, you can quickly pay for all the upgrades to run it instead of buying super expensive race gas all the time, which means you won't drive the car much if it takes $180 to fill the tank with 100 octane vs. $40 a tank for E85.
Battenrunner is offline  
Reply With Quote
Old November 8th, 2018, 06:51 AM
  #3  
Registered User
Thread Starter
 
Join Date: Jun 2018
Posts: 61
Thanks Battenrunner. I will definitely look into the e85 route. Do you know if I can keep my current tank and lines with e85? I know I would need a pump and carb for sure.
teamwieland is offline  
Reply With Quote
Old November 8th, 2018, 08:54 AM
  #4  
Registered User
 
Join Date: May 2018
Posts: 139
I looked at the mechanical Rob MC pump , but it doesnít look to be E85 capable.

I know that tanks Inc has a nice tank that is deeper than stock, and it is made to hold a fuel pump inside.

They are nice people and knowledgeable.

i would give them a call and ask which of their fuel pumps will work reliably with E85 and run a low pressure bypass fuel regulator on a loop to allow excess fuel to return to the tank.

Because you are feeding pressurized fuel through the lines, you will need to remove any plain rubber sections and replace with Earls Vapor guard as well as making a flared end on the tubing to allow an AN fitting on it. You can probably flow enough E85 with a 3/8 steel line and -6 AN fittings.

You will need a return line back to the tank from the bypass regulator as well. You will probably want a 5/16 return line or larger.

There are several builders of Holley double pump carbs that are built specifically for use with E85. Since your engine combo should be pretty hot, and you are going to install a higher stall converter, donít mess with a Holley vacuum secondary carb in my opinion.



Battenrunner is offline  
Reply With Quote
Old November 9th, 2018, 01:07 PM
  #5  
Registered User
 
Join Date: Feb 2009
Posts: 152
Look up Mark Sullens for an E85 carb... One of the best in the business.. He should be able to help you out. He can likely convert your current carb. He has done two Holley DP's for me.
1arunem is offline  
Reply With Quote
Old November 9th, 2018, 04:22 PM
  #6  
Registered User
Thread Starter
 
Join Date: Jun 2018
Posts: 61
Thanks 1arunem. I am pretty much sold on e85 right now based on my situation. I do have easy access to e85 in my area. I'm going to pay either way to make this project come together so I might as well be able to buy cheap fuel when it's over. I was thinking of getting a Quick fuel e85 based on a few conversations, but after your thread wonder if I should consider converting my Holley 850 DP, or just having an e85 carb from the start. Would love to hear your experience with e85, and the carburetor/fuel system situation as well. I've got everything spec'd out at TanksInc.com, and need to make a carburetor decision asap. Appreciate your input.
teamwieland is offline  
Reply With Quote
Old Yesterday, 02:29 PM
  #7  
Registered User
 
Join Date: Aug 2012
Location: Colorado Springs Colorado/Thousand Oaks Ca
Posts: 334
I would find it hard to believe you can't run pump 91 octane @ 6000 plus feet, with a 23.50 baro, especially with the cam that was selected. A simple cranking compression test will tell you what you need to know, if its over 150 I would be very surprised.
VORTECPRO is offline  
Reply With Quote
Old Yesterday, 02:31 PM
  #8  
Registered User
Thread Starter
 
Join Date: Jun 2018
Posts: 61
All 8 cylinders were compression tested at 210 psi at 6500í.
teamwieland is offline  
Reply With Quote
Old Today, 01:04 PM
  #9  
Registered User
 
Join Date: Feb 2009
Posts: 152
I and several buddies run E85. The car I run it on is a drag only car. However a few friends use it in their street/strip cars.

The ONLY changes I made were getting rid of the fuel filter with paper media (bought one with stainless media), changed to a number 7 heat range plug and of course the carb conversion. The car has a plastic fuel cell.

Mark is great to work with IF you listen to what he tells you to do. He has years of experience with E85 and builds them for many types of applications.

E85 is more finicky, more sensitive to temp, etc.

If you run your car regularly, you should have no real issues. Letting it sit with fuel in it for long periods of time can cause issues. I have been running it for a few years with no real issues other than one time. I usually run the car out of fuel (turn fuel pump off) whenever I put it up for a while. However one time I let the car sit for months without being run and hadn't run it out of fuel. I had to take the carb apart and clean it. It will develop a chalky or even jelly like residue in the bowls if left too long .

I much rather pay $2.50 a gallon then $10 a gallon for 110.

I also run Lucas Ethanol treatment with every jug.
1arunem is offline  
Reply With Quote
Old Today, 04:26 PM
  #10  
Registered User
Thread Starter
 
Join Date: Jun 2018
Posts: 61
1arunem it sounds like you are pretty satisfied overall with e85 even with the idiosyncrasies of the fuel. Should have parts delivered and motor put back together in the next week or so and I'd like to get the motor over to the dyno tuner ASAP. As such I'll need to at least have the carburetor figured out for e85 by then and can deal with the rest of the fuel system over the winter. Mark (CutlassEFI) can help me out with a Quickfuel e85 if I go that route or it sounds like Mark Sullens is a great way to go if I want to rebuild my Holley 850 DP. Any thoughts as to just using my well functioning Holley 850 and having it converted to e85 or biting the bullet with a carburetor built for e85? Not sure on cost to convert but the e85 carbs look very pricey.
teamwieland is offline  
Reply With Quote
Reply
 
 
 
Related Topics
Thread
Thread Starter
Forum
Replies
Last Post
corvettetops
Racing and High Performance
4
May 31st, 2018 05:52 PM
AK71CutlassS
Big Blocks
8
May 14th, 2014 09:00 PM
EightballZ
Big Blocks
2
November 5th, 2013 06:56 AM
wildwillie1981
Racing and High Performance
5
April 24th, 2013 05:19 PM
TORTUS
Big Blocks
28
October 18th, 2012 05:50 AM


Thread Tools
Search this Thread