What brands are available?

Looking for a comp of 12:1 or higher...

 

To answer that, it would be nice to know what type of piston (flat top, domed, valve reliefs size), and in which motor size.

 

stock LS1

 

In that case, 62cc or 59cc chamber heads milled would achieve that. Notching pistons would be required to fit bigger cams.
To be more specific 57cc with .040 gaskets will yield 12.1:1

Just be aware that DCR should be taken into consideration to run pump fuel, but if race fuel (or other) available with enough octane it is not that hard.

 

11:1 = 93 all day

 

Thanks for the answer... I want to use a 224/228 cam. Do i have to Notch the pistons?

I have talked with AFR about the 205 heads milled down to 58cc. But i´d want to see whats more on the market.

What do you "high comp guys" use and have you had any problems?

 

224/228 and what LSA/ICL (like 112+4)

 

your dcr will be through the roof with a 224/228. i had 9.0 dcr with 11:7 scr with a 228 on a 112 +2. it ran fine on 93 but i have no idea how that e85 stuff is.

 

That´s what i am going to try to find out

With an octane of 105 i dont think there should be any problems.

What type of heads and cc do you use?

 

RUNN,

DCR is dynamic compression. On a 105 Octane, 9>9.2 DCR would be the max I would run. To find your DCR first you need to give us at what LSA and ICL would the cam be. Based on that, you choose your CC on heads. Differen LSA and ICL will reduce or augment DCR.

 

The stuff I wanted to know in my thread, but no answers yet...they must like you better than me

So it takes a 57cc head to reach 12:1 huh...don't think you can mill much more than that?

The cam in question here is a 110+0 grind.

 

224/228 110+0 on 12.16:1, 57cc heads, .040 gasket and stock block is around
9.53 DCR, too high IMO even for Ethanol

 

Wow that's pretty high.

Does the DCR drop much if you go 226/230?

Patrick G runs a 224/228 110 and has around 8.7-8.8 DCR but his motor may not be stock.

 

Thanks for the help...

224/228 .581.588@114 this is the cam... What cc should i have on AFR 205 heads?

 

BTW did you read the link here https://ls1tech.com/forums/showpost....2&postcount=52 about an engine with 19:1 that runs on E85, And the cars in Brazil use 15:1 to 16:1 but i dont know the DCR on those

But E85 is different than gas since E85 cools the intake charge more and therefore it´s more knock-resistent and can tolerate more boost or a higher CR. And it also makes the engine run cooler and to some degree, even safer.
On e85 you cant only look at the octane.

I dont know, Damn we need more info on this

 

That cam does not fit the "torque cam" description that you mentioned at all.

It needs to be on a 110.

 

I havn´t mentioned any torque cam. This is the cam that AFR recommends to use with there heads. But i´m not a camexpert I´m not sure of what cam i should use I just figured it would be a good choice since AFR heads have gotten good numbers with it, i think AFR 6016 is the correct name.

But what cam should we (you and i )use to get a high DCR that we want.

This is an interesting thread https://ls1tech.com/forums/generation-iii-internal-engine/481382-torque-coming-out-my-ears-cam-change.html

" I asked Thunder Racing to grind me up a Super Torquey cam that would have excellent street manners. Here's what they came up with:
224/228 .637/.639 110LSA (+0)."
"My dynamic compression has risen from 8.34:1 to 8:73:1!"

That might be a much better choice.

 

Sorry I swore you did. That is more what i'm talking about

 

I´ve posted a couple of questions about DCR with E85 on a couple of forums, See if i get any respons.

But if we look at FI cars that have swithed to E85 they can increase there boost way more over gas so i dont think why it shouldn´t be the same on NA. I think a DCR over 9:1 shouldn´t be any problems but it would be nice to have some facts