Help me pick the best JunkYard Sirius Engine for me

[CallMeCrazy]

I am doing an e30 4g63 500rwhp build and I have started to doing my homework for the engine. I am wanting to source my engine from a junkyard and build it myself. (I'm looking for the best value). It seems to be a lot harder to find a DSM in the graveyard these days so I have started looking at the variant style engines. Currently I am looking at the G4JS, it seems to be readily available for next to nothing, evo style head, oil squirters, and of course 2.4L which would produce better torque.

If I am to go with this engine, I need to know what compression ratio will be best for boost, and what internal parts I will need to replace on the bottom end, as I will replace all the top end with Evo parts.

If the G4JS is not a good choice for me, which Sirius engine would be? It looks like I will have to find a N/A engine and modify it to handle boost (oil squirters ect…) so I am just trying to figure out which piece of junk will be my treasure!

 

[Hickory-NC-2Ggsx]

The 4g64 is a great engine, I myself have ran the 4g64 stock bottom end to 410whp with just a 4g63 head and headstuds. For 500 i would do some basic off the shelf rods and pistons 9.1 c.r.
For oil squirters its not needed. I wouldnt worry about it at all. As far as the head goes a 6 bolt head to help it breath through out the rpm.

 

[BLACK'98DSM]

I am doing an e30 4g63 500rwhp build and I have started to doing my homework for the engine. I am wanting to source my engine from a junkyard and build it myself. (I'm looking for the best value). It seems to be a lot harder to find a DSM in the graveyard these days so I have started looking at the variant style engines. Currently I am looking at the G4JS, it seems to be readily available for next to nothing, evo style head, oil squirters, and of course 2.4L which would produce better torque.

If I am to go with this engine, I need to know what compression ratio will be best for boost, and what internal parts I will need to replace on the bottom end, as I will replace all the top end with Evo parts.

If the G4JS is not a good choice for me, which Sirius engine would be? It looks like I will have to find a N/A engine and modify it to handle boost (oil squirters ect…) so I am just trying to figure out which piece of junk will be my treasure!

Pull-A-Part. Atlanta: North, South, and East all have a couple of DSMs. I know they provide you with an engine crane, just bring your truck. They have 3 2.0s, 5 2.4s, and 4 3.0s. https://www.pullapart.com/inventory/search/

 

[CallMeCrazy]

Thanks, Ill head out there this weekend. Last couple times I have been, the engines had already found a new warm home.

 

[ThunderChild]

I'll second the 4g64, 3rd gen block for availability and single serpentine belt ease, maybe with a g4js head. Basically an Evo 2.4 for you. Since you're doing rwd, make sure to grab the water pipe as well, the g4js has a unique thermostat housing as well. Will have to use dsm style cam gears too as the g4js uses a different timing belt profile and tooth pitch.
Only reason not to use the g4js bottom end is the front case is totally different, so none of the Evo/DSM stuff will work and you'd have to use all Kia optima accessories. You may have to block a couple oil drain back holes, but I believe the 3g 2.4 block affords bolt on capability.

Otherwise you can use whatever flavor Evo/DSM cams, valves, springs retainers, gears, turbos/exh manifolds and internals you want. Have to use Evo or Kia intake manifold, the Kia is touted to be better flowing (along with the head). I'd recommend ditching the plastic Kia fuel rail and find a used Evo one for piece of mind and easier afpr adaptation.

For 500, depending on the turbo desired, 8.5-9:1 should be sufficient with a moderate sized turbo, hx35 would make it fairly easy.

 

[kronus]

I have little to add except for NOT using the 6-bolt head. Nothing wrong with it, and it will flow a good amount, but the newer style heads like the 7-bolt and Kia heads are more efficient. It seems like all of the serious road guys start with a 7-bolt 2g head.

 

[ThunderChild]

I think alot of that depends on a few factors. I'd consider the 1g a good "mass flow" head, but considering the 2g+ heads can get very close to peak flow (stock for stock) and have much better low-mid velocity, it comes down to what you're building and what's available.

I still plan on using the 1g head for some stuff, but I'll agree the Evo/Kia heads are a great upgrade, for cheap with the kia head too.