View unanswered posts | View active topics It is currently Fri Aug 18, 2017 12:17 pm



Reply to topic  [ 29 posts ]  Go to page 1, 2, 3  Next
 8896 2 curcuit E85 Conversion questions 
Author Message

Joined: Sun Jun 18, 2017 4:29 pm
Posts: 8
First I would like to thank Mark for help with my registering problem.

I have a old 8896 that I am wanting to convert on a budget to E85 and make a 2 circuit. I have read every thread I could find about this on the old MSV site. After some searching I discovered this one thankfully.

As stated I am working on the 8896, It is going on a 2700lb drag car with a 468 BBC which currently has another 8896 on gas. I have a good background working with carbs, as I have built a few for blow thru and E85 in the past.

After reading up for my current project (on the MSV site), I have a good understanding what needs changed, but mainly looking for help with a baseline setup to get started.

My main questions at this point are.
Is there any way possible to use the original standard boosters?
If not what ones and where is the best place to buy?
Anyone have some good baseline starting settings?

I have the 8896 along with a set of the green QF metering blocks already left over from another project.

Any help will be greatly appreciated Thanks.


Tue Jun 20, 2017 8:32 am
Profile

Joined: Mon Oct 21, 2013 12:15 am
Posts: 226
Location: San Diego, CA
You can reuse your current boosters, but you need to disassemble them and enlarge the holes in the inserts (increase holes by .005"), as well as the booster legs (Increase to .185"). You will need to buy new stake tubes, and have them sized to .180" from BLP. If you want to step it up a little, you can buy 12-hole billet inserts from BLP as well (Increase the discharge holes to .067").

The best thing to do is to remove the well caps on your green blocks, and spec them out:

Mainwell - .180" at the bottom, and follow it up with a #2 tapered reamer to the bottom

Exit channel - .170"

Emulsion - .018"-.020"

IFR - .046" (bottom)

HSAB - .024"-.026"

IAB - .052"-.055"

Jetting should fall in the .132"-.136" range (depending on horsepower and timing). If you give me the horsepower level, I can get you close.

This is a good baseline to start from. I would also recommend BLP bottom-feed N/S (.140"). I use the .150" bottom-feeds, and they work great.

If you plan to use a Power Valve, increase the PVCR to .089"-.096"


Tue Jun 20, 2017 11:39 am
Profile

Joined: Sun Jun 18, 2017 4:29 pm
Posts: 8
Thank you. My stock boosters are the standard non annular ones.

I will spec the blocks as suggested, when everyone relocates the IFR to the lower spot are they using a 8-32 size "jet"?

I would guess this engine to be in the 675 HP range.


Tue Jun 20, 2017 1:08 pm
Profile

Joined: Mon Oct 21, 2013 12:15 am
Posts: 226
Location: San Diego, CA
For the IFR, use 6-32 x 1/8" set screws.

Jetting - start at .136"

Boosters - I would recommend calling BLP, and getting annular non-skirted boosters with billet 12-hole inserts, and stake tubes. You will be much happier with them.


Tue Jun 20, 2017 2:10 pm
Profile
Site Admin
User avatar

Joined: Fri Feb 08, 2013 5:50 pm
Posts: 2359
Straight boosters can be used, you want to enlarge the passage all the way thru to around .180. Annulars would be better, booster banjos have to be modified to fit the old style bodies as the old ones are not available anymore. The ends are wider where they fit the body, I use a tool grinder or you can use a belt sander and fit by hand. For booster inserts I like more smaller holes, 16 hole .059 at least. .140 viton BLP N&S, I don't use bottom feed as they restrict flow. The rest of Rev's suggestions will be good, I find jetting between .138 and .144.


Tue Jun 20, 2017 7:25 pm
Profile

Joined: Sun Jun 18, 2017 4:29 pm
Posts: 8
Thanks again guys. Mark if you think its possible to get by with the standard boosters, I won't be out much if anything to get them a try.


Tue Jun 20, 2017 7:38 pm
Profile

Joined: Sun Jun 18, 2017 4:29 pm
Posts: 8
What size squirters .047? What size on the TSJ?


Tue Jun 20, 2017 8:39 pm
Profile

Joined: Mon Oct 21, 2013 12:15 am
Posts: 226
Location: San Diego, CA
Start your squirters at .045"

TSJ - it varies depending on slot length and exposure. I would leave it unmodified for now, and see where your tune leads you. I have played with different sizes of TSJ from .052" - .102", and what I have found is that the more you restrict the transfer slot, the bigger the accelerator nozzle gets, to cover up the lean spot. If you leave it alone for now, you can tune everything else, and come back to it.

If you are using an AFR gauge, you can do a steady throttle at 1800-2000 RPM, note the reading, and reduce the size of the transfer slot feed hole by the same percentage as your desired increase in AFR/LAMBDA.


Wed Jun 21, 2017 12:31 am
Profile
Site Admin
User avatar

Joined: Fri Feb 08, 2013 5:50 pm
Posts: 2359
Usually in the .070's for a t-slot jet, , .050-.060 for the idle bleed to go with it. .040-.050 for squirter, whatever the least amount to cover any stumble.


Wed Jun 21, 2017 1:59 pm
Profile

Joined: Sun Jun 18, 2017 4:29 pm
Posts: 8
I am currently waiting on parts. I have the boosters drilled, the metering blocks ready with the IFR relocated to the bottom. I am setting up per Rev's and Mark's suggestions.

The overall jetting and emulsion seems rich to me, I didn't expect to use this large of jet along with such small emulsions. Lol


Thu Jun 22, 2017 3:29 pm
Profile
Display posts from previous:  Sort by  
Reply to topic   [ 29 posts ]  Go to page 1, 2, 3  Next

Who is online

Users browsing this forum: No registered users and 1 guest


You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot post attachments in this forum

Search for:
Jump to:  
cron
Powered by phpBB® Forum Software © phpBB Group
Designed by ST Software for PTF.