the redtop and iron eco combustion chambers are both 43cc :(

Pir0 · Post by **Pir0** » Sat Dec 01, 2007 12:37 am

So , technically if you bolted an XE head straight onto an XEV block, the CR should be lower?

This is realllllly interesting, how much lower do you reckon it would be like this? It could save doing the 2 head gaskets when turbo'ing a redtop as the ecotec blocks are a dim in a dozen over here.

[EDIT]: Or is this where that +/- 1.5:1 CR comes into play? Seeing as the X in the engine code is from 10:1 to 11.5:1

gse_turbo · Post by **gse_turbo** » Sat Dec 01, 2007 12:58 am

actually IF, and its a big if... IF the head volumes where different that would be perfect. i have yet to check my numbers and do all the math but hope full i can do it tonight and have a straight answer. i like the potential of this, redtop head on a eco block would be a nice combination.

garrett

Pir0 · Post by **Pir0** » Sat Dec 01, 2007 1:03 am

I'm liking this new find aswell, I always thought the eco bottom end was the same as a redtops. Partially because the mechanic i know uses eco bottom ends for redtop heads when he has no xe bottom ends.

I assumed they were the exact same

Well, it's too late for me to do all the maths, so i'll read up on your finds tomorrow after work, and see what I can come up with myself.

I'm still not 100% sure about CRs in relation to turbos, I know c20LETs run a CR of 8.5:1-9.0:1 so, maybe the eco block [or just pistons] could bring it down to that? If not looks like the trusty 2 head gasket's the way to go when turbo'ing it...

One last question before I hit the sack, in relation to turbo'ing a car, less CR = better for larger turbos? Orrrrr how does that work exactly?

Cheers in advance, and glad you got what info you needed so far, hope those pics etc helped a bit, g'night

gse_turbo · Post by **gse_turbo** » Sat Dec 01, 2007 1:20 am

the specs and dimentions on the eco and redtop bottom ends are identical.

as for the CR on a turbo car you want lower copression to reduce the change of detination. you could run higher compression on a turbo build but you'd have to run a higher octain petrol or and alcohal based fuel like E85. the reason most builder shoot for 8.0:1-8.5:1 is because 87-91 octain is easy to find world wide.

lower compession is a safey/longevity measure. if you were to run E85 with a turbo at 9.5:1 you would get more HP then the same setup at 8.0:1. this is the biggest reason that i'm trying to sell the 2.2 eco bottome end i have. i started the build with petrol in mind and then desided to switch to E85 and my current CR is 8.0:1.

Pir0 · Post by **Pir0** » Sun Dec 02, 2007 12:15 am

Is the 2.2 eco block the same as the 2.0? Lower compression pistons to make up for the limited space in the head combustion chamber?

[EDIT]: I sent you an email/pm btw, forgot to say

gse_turbo · Post by **gse_turbo** » Tue Dec 04, 2007 5:44 pm

Pir0 wrote:Is the 2.2 eco block the same as the 2.0? Lower compression pistons to make up for the limited space in the head combustion chamber?

quite, that is with the iron 2.0/2.2 eco's, the aluminium ecotec is a whole other storry. the 2.0 and 2.2 are both at 9.6:1, they basically use the same pistons with different rods and block height.

Post by **Efratech** » Tue Dec 04, 2007 6:49 pm

whats the cc on the ecotec head?

gse_turbo · Post by **gse_turbo** » Tue Dec 04, 2007 7:09 pm

i forgot to measure that this week end, i'll see if i cant do that here i a a little while.

gse_turbo · Post by **gse_turbo** » Wed Dec 05, 2007 5:51 pm

well i cc'd the head last night and... well.... the redtop and the iron eco heads are both 43cc!

sorry for speculating but i did get the info i was looking for.

so the pojects continue....

Pir0 · Post by **Pir0** » Wed Dec 05, 2007 10:30 pm

So this means the pistons from an eco bloc kwould fit a redtop block and run correctly @ roughly the same compression?

Is this a set back for you? I thought you were going to be running a higher compression ratio anyway for the E85 fuel

gse_turbo · Post by **gse_turbo** » Wed Dec 05, 2007 11:29 pm

Pir0 wrote:So this means the pistons from an eco bloc kwould fit a redtop block and run correctly @ roughly the same compression?

Is this a set back for you? I thought you were going to be running a higher compression ratio anyway for the E85 fuel

well now i'm fairly sure they are even the part number providing the XEV uses a floating pin.

it's not really a setback for me, it actually make plenty sence, it just would have been nice to find a little known upgrade.

i did get the info that i was originally after, i plan to use XE pistons in an iron eco motor. i also had a couple other things in mind which the two pistons being the same helps but i'll get into that another time.

Post by **Efratech** » Thu Dec 06, 2007 2:27 pm

the iron ecotec is basicly an 8v with a 16v head

Pir0 · Post by **Pir0** » Thu Dec 06, 2007 4:00 pm

Is what way is it an 8v? Wouldnt the valves foul the pistons if the pistons were like an 8vs?

gse_turbo · Post by **gse_turbo** » Thu Dec 06, 2007 5:33 pm

Efrain A. wrote:the iron ecotec is basicly an 8v with a 16v head

i'll agree and disagree... the rods on all the iron ecotecs are the same 'weaker' style as the 8v motors but that where the similarties end, for the most part.

ALL the "R90" motors (1.8/2.0/2.2 SOHC & DOHC motors '85-current) are based on the same basic casting with each having its own small veriation. so to say the eco favors one motor or the other isn't really the case. the eco does have valve releifes/pockets like the redtops but because of the smaller valves in the eco they only cut two instead of four.

Post by **Efratech** » Thu Dec 06, 2007 7:24 pm

thats why i said, an 8v (block)... with a 16v head