1996 RVR super sports gear is similar to 1G or 2G engine?

[Starfire118]

First post so sorry if I mess somthing up. I have an RVR that I'm trying to fix up but I'm not certain what 4g63t generation I have. All the part numbers from online manuals read out to EVO III parts but the head is looking identical to the 2g head I have lying around.

Is it a mismatch engine from the factory and/or is there a way to tell from the diagrams which generation of parts I should be getting? Thanks.

P.S. I don't fully understand the 6 vs 7 bolt head differentiation, so it's hard for me to check that way.

 

[1990TSIAWDTALON]

6 bolt heads have 12mm holes for the head bolts/studs.
7 bolt heads have 11mm holes for the head bolts/studs.

When I use a 7 bolt head on my 6 bolt bottom ends, I have to enlarge the 7 bolt head holes to 12mm to accommodate my larger diameter head studs. Other than that, they have the same size combustion chamber volume and components.

A 7 bolt motor will have a slight "hump" on the oil pan flange just under the harmonic balancer and a 6 bolt will be flat from one side of the block to the other in that location. You might try looking at the oil pan and see if you see or feel a hump or not when running your hand on the oil pan flange behind the balancer.

Of course the true way to tell is to count the bolts that hold the flywheel on. Since the Sports Gear model was produced from 94-97, it looks like, I would bet it is a 7 bolt motor.

 

[Kryndon]

Marty's dead on the money, and I'm sure Hiroshi may chime in here with his exquisite knowledge on JDM vehicles if he sees this thread.

From my knowledge, the RVR simply has an Evo 3 motor, it even has the same intake manifold. The cams may differ but you need to check the stamps on them and refer to the camshaft identification thread to learn their specs. It is a 7 bolt motor for sure and would be the single thrust bearing type, so you could look at 2g 7 bolt DSM engine parts for it.

Personally I am still unsure if the auto trans from an RVR would work on a 2G DSM even with some modification, but that warrants its own thread.

 

[steve]

I don't know much on this topic but I will add that there is a difference in the intake port size between heads from 1G and 2G DSM's. IIRC, 1G 6 and 7 bolt heads have big ports and 2G 7 bolt heads small ports.

 

[Canadian_CD9A]

The RVR would be a 7-bolt. It's functionally extremely similar to the 2G DSM and Evo 123 engine, but with minor differences. Most parts for the Evo 123 or 2G DSM engine will fit the RVR engine. The 7-bolt cylinder head ports are smaller than the 6-bolt motors, which increases air intake velocity and makes it a bit more responsive at low RPM; the intake manifolds do not interchange between 6-bolt and 7-bolt. The RVR head is going to be essentially the same as the 2G DSM or Evo 123, with the possible exception of the camshafts, though the difference is too small to matter. If your head is the same as a 2G DSM, it's likely the original.

 

[1990TSIAWDTALON]

I don't know much on this topic but I will add that there is a difference in the intake port size between heads from 1G and 2G DSM's. IIRC, 1G 6 and 7 bolt heads have big ports and 2G 7 bolt heads small ports.

That would be correct, thanks Steve!

 

[DSMPT]

All 4g63 equipped RVR's engine is 7 bolt. The RVR which comes with a EVO engine (Not EVO 3 engine, it's the same as EVO 2) is only the turbo Hyper Sports Gear. That has 1g style oil squirters the ones with check valve on main oil galley. The other 4g63T equipped RVR's (like the OP's RVR) engine is like 95-96 2G DSM engine with 2g DSM style oil squirters. And non turbo 4g63 equipped RVRs come with CR10.5:1 pistons like Euro 2G.