Main Cap strength

decyphex · Post by **decyphex** » Mon Jul 23, 2007 1:36 am

How strong are the main caps in the T20SED and similar motors? Do the C20LET motors have main cap cradles or something to make it stronger?

gse_turbo · Post by **gse_turbo** » Mon Jul 23, 2007 7:05 pm

none of the 2.0's have a main support but i can make you one on the CNC.

the 2.2 comes with a main support but the bottm end of the block is cast completely different. you'd have to use a 2.2 block in order to use the support.

garrett

Post by **PrecisionBoost** » Tue Jul 24, 2007 4:34 am

I'm pretty sure the U20SED has the cap cradle as well..... basicly any of the 2.0L and 2.2L engines with the aluminum oil pan will have the extra support.

It would probably be a pain to install a support like that afterwards..... it could be done.... but it would be a bit of a pain to line up everything and drill and tap it to fit.

I don't remeber what the C20LET has for support..... the C20GET had nothing.... so I'd assume that the LET didn't have anything either.

I remember seeing some nice conversions on high horsepower 2.0L engines..... they basicly had completely new caps made and integrated a solid plate (with slots for the crank) that connected the mains to the block.

Post by **Efratech** » Tue Jul 24, 2007 5:33 am

XE/LET dont have that.

gse_turbo · Post by **gse_turbo** » Tue Jul 24, 2007 4:09 pm

PrecisionBoost wrote: I remember seeing some nice conversions on high horsepower 2.0L engines..... they basicly had completely new caps made and integrated a solid plate (with slots for the crank) that connected the mains to the block.

this is what i'm talking about when i say i can make one on the CNC. i already have the blue prints, just haven't made one yet.

you're right about the aluminum oil pan, i just didn't remember which motors came with the aluminum pans.

garrett

decyphex · Post by **decyphex** » Thu Jul 26, 2007 7:24 pm

Hmmm.. Mine doesn't have a support, does that mean it's not an aluminum pan?

gse_turbo · Post by **gse_turbo** » Thu Jul 26, 2007 7:35 pm

you would have to use something like this

let me know if you're interested in it.

you will have to use arp studs.

you might need to use spacers like what Tom did and use opel main studs and not the VW studs i've writen about.

garrett

gse_turbo · Post by **gse_turbo** » Thu Jul 26, 2007 7:39 pm

are you building a T20/T22 or the C20 that came in the Sunbird?

if you're using the C20 from the Sunbird then you'll have to get the caps flycut with them installed on the block to make then level with the bottom of the block.

garrett

decyphex · Post by **decyphex** » Fri Jul 27, 2007 3:05 am

gse_turbo wrote:are you building a T20/T22 or the C20 that came in the Sunbird?

if you're using the C20 from the Sunbird then you'll have to get the caps flycut with them installed on the block to make then level with the bottom of the block.

garrett

T20 is what Im building. At what point is a brace like this necessary?

Post by **PrecisionBoost** » Fri Jul 27, 2007 4:52 am

That's a damned good question..... I don't think anybody knows for sure.

I know that there are 400+hp C20GET and C20LET engines without the brace..... but the general concensus is that these newer blocks are not as strong as the old blocks.

I don't know if there is anything to that... but you would think that GM would avoid installing an expensive aluminum pan and support system if they could.

After all... the old pressed steel pans probably cost them about $1 each.

With regards to the CNC plate.... yes... that's basicly what I'm talking about.... except that they don't use the factory caps... they install bigger ones with more metal on them... and the one set I noticed had four cap mount points instead of just two.

decyphex · Post by **decyphex** » Sat Jul 28, 2007 4:05 am

But if I'm looking at maybe 250hp or so.. Would my stock mains be fine?

Post by **PrecisionBoost** » Sat Jul 28, 2007 4:34 am

I don't see why not.... at 250hp your barely pushing it past 100bhp/L. but you could allways convert them over to ARP studs if you were concerned.

I have a feeling the main brace was more for supporting the block than the mains.... but I could be wrong.

decyphex · Post by **decyphex** » Sun Jul 29, 2007 12:44 am

PrecisionBoost wrote:I don't see why not.... at 250hp your barely pushing it past 100bhp/L. but you could allways convert them over to ARP studs if you were concerned.

I have a feeling the main brace was more for supporting the block than the mains.... but I could be wrong.

The other reason I asked was that my machinist seemed to show some concern for the strength of the mains when used in a turbo setup. So I don't know, I guess they'll be fine then. I'm not aiming for 500 or anything lol. I've seen that kind of number out of one of these motors before though!! In a Vauxhall Calibra. It went from 0-100mph in about 9-10 seconds. All wheel drive too!! THAT REALLY HELPS!

I have ARP rod bolts and head studs right now, I should have got mains, but I will if I go turbo.

gse_turbo · Post by **gse_turbo** » Tue Jul 31, 2007 4:44 pm

what block are you using?

garrett

decyphex · Post by **decyphex** » Tue Jul 31, 2007 5:42 pm

Im using a T20SED block from a 2000 Daewoo Nubira.

I also have a C20NE block here from a 1992 Pontiac Sunbird. This engine was replaced with the T20.

Oh.. Do you guys all have windage trays built into your oil pan gaskets?