E85 Safe/Max Dynamic Comp Ratio

General engine tech -- Drag Racing to Circle Track

Moderator: Team

Dave B
Pro
Pro
Posts: 359
Joined: Fri Jan 20, 2023 10:07 am
Location: Midwest

Re: E85 Safe/Max Dynamic Comp Ratio

Post by Dave B »

Orr89rocz wrote: Sat Sep 02, 2023 7:32 pm You are doing things i never heard anyone else do on that fuel. Hats off
I don't think we have anything different than most. I think where allot of guys have problems is in general block and parts prep. I see so many pistons from Diamond,je,wiseco etc that need huge dome and edge work. I think guys spend 1500.00 on pistons and think they are good to go. Boring blocks on centers, just proper block blueprinting in general. Most guys don't have their engs sealed up. Oil, and heat don't mix well I'm comb area. Allot of engs have head sealing issue and I bet it's 95 percent builder error. Even this sprint engine is oring sealed with receiver grooves. Proper fasteners and torque process seem to still be a huge issue for several guys. If a engine is happy it will take some abuse etc. I really find much of what I'm told not to do in cam events, fuel afr etc is no where close to what really works. So many guys have issues and quit before they learn. My brother's and I have spent 1000s from supposed best in the industry to only be disappointed,so we didn't give up on race development,we just quit buying and listening to others, we do our own engs,trans,cars, shock development and converter work. You learn way more when you go this route.
skinny z
HotPass
HotPass
Posts: 2682
Joined: Tue Mar 11, 2008 8:42 am
Location: AB. CA.

Re: E85 Safe/Max Dynamic Comp Ratio

Post by skinny z »

Subject matter notwithstanding...

Cool.jpg

That's about as cool as it gets.
A 72 Chevelle wagon was my early teens car (my mother's actually which I proceeded to beat on unmercifully). 307 and all.
An SBC with a blower is icing on the cake.
Pie in the sky for me but still on the list.
I wish...
You do not have the required permissions to view the files attached to this post.
Kevin
Dave B
Pro
Pro
Posts: 359
Joined: Fri Jan 20, 2023 10:07 am
Location: Midwest

Re: E85 Safe/Max Dynamic Comp Ratio

Post by Dave B »

IMG_20230902_133246949.jpg
Or the view or lack of, cruising your blown and injected Vette down the ave. The smell of e85 rolling out of your 5" exhaust. When you lite it up at speed, you better learn to look a block ahead or so.lol.
You do not have the required permissions to view the files attached to this post.
bob460
Expert
Expert
Posts: 571
Joined: Thu Sep 26, 2019 6:19 am
Location: Australia

Re: E85 Safe/Max Dynamic Comp Ratio

Post by bob460 »

I'm a big fan of E85, love the smell.............at a recent car night meet down here, their was a blown bronco 1,200hp on E85. As we were leaving i just followed the bronco with my window down and the smell was heaven...lol. As soon he put his foot down that bronco was moving.

Time for me to up my comp and run E85!!
skinny z
HotPass
HotPass
Posts: 2682
Joined: Tue Mar 11, 2008 8:42 am
Location: AB. CA.

Re: E85 Safe/Max Dynamic Comp Ratio

Post by skinny z »

Dave B wrote: Sun Sep 03, 2023 7:39 pm ...blown and injected Vette down the ave.
What generation Vette?
Kevin
Dave B
Pro
Pro
Posts: 359
Joined: Fri Jan 20, 2023 10:07 am
Location: Midwest

Re: E85 Safe/Max Dynamic Comp Ratio

Post by Dave B »

C3 on that one.
skinny z
HotPass
HotPass
Posts: 2682
Joined: Tue Mar 11, 2008 8:42 am
Location: AB. CA.

Re: E85 Safe/Max Dynamic Comp Ratio

Post by skinny z »

Dave B wrote: Mon Sep 04, 2023 12:23 am C3 on that one.
Also cool.
My experiences driving a 1970 example was that of visibility, or lack thereof in this case, past that long hood. I can see that a blower does little in the way of improving that!

Question: Looks to be the injectors are above the blower. Is there a benefit to charge cooling if that's the case?
Kevin
Dave B
Pro
Pro
Posts: 359
Joined: Fri Jan 20, 2023 10:07 am
Location: Midwest

Re: E85 Safe/Max Dynamic Comp Ratio

Post by Dave B »

skinny z wrote: Mon Sep 04, 2023 11:11 am
Dave B wrote: Mon Sep 04, 2023 12:23 am C3 on that one.
Also cool.
My experiences driving a 1970 example was that of visibility, or lack thereof in this case, past that long hood. I can see that a blower does little in the way of improving that!

Question: Looks to be the injectors are above the blower. Is there a benefit to charge cooling if that's the case?
I think it's a good thing to have them up there for heat. But a blower manifold is so short in runners that makes for little room to mount them there. You have no clearance at valve cover or linkage etc. EFI is nice for street but on our blower stuff that runs hard ,I would soon have mfi.Blower itself needs fuel run through it to keep it from eating itself. Our good running mfi stuff has 8 lines into blower and 1 line per intake runner.
djr48312
New Member
New Member
Posts: 14
Joined: Mon Nov 13, 2023 2:12 pm
Location: Dallas

Re: E85 Safe/Max Dynamic Comp Ratio

Post by djr48312 »

Hi all. I was talking about max cr for e85 naturally aspirated and i was confident 14:1 is not a big deal. I was looking at an article that says up to 16:1 on e85...

Someone asked "why" would we want to do this. If you live in an area where e85 is plentiful, we would build a 14:1 e85 naturally aspirated engine because we want to make more power and more torque than a 10:1 or 11:1 engine. Each pt of cr is said to be around 4% torque increase as per David Vizard building horse power volume 1. So from 10:1 to 14:1 is 16% increase, perhaps more with a good tune.

It's already proven in turbo and boosted applications that e85 is a big deal. Where you can run full timing in boost and make 50-60rwhp gain on evena 7-9psi application and over 100rwhp gain on something that is 16psi or higher. e85 also is very hard to detonate, so the chance of blown gaskets or pistons is reduced greatly.

We would also want to run 14:1 on the street because it SOUNDS better. Some people care about the sound of their ride and higher compression sounds more radical and sexy.
Post Reply