Using 2.3 block with a 2.0 HOT K head?

[jcm]

I've read various threads about using different blocks with no answer to my Q:

I have a nice 80K 02 head from a K engine with a restorable 2.3 short block that I'd like to rebuild and match up. I know the block stroke and pistons are different but expect the head will bolt on fine. I believe the timing chains and and gearing to be the same. Is this configuaration similar or parallel to a viggen engine?

The ECU will remain from an 02 SE vert.

Does anyone see any fault in this marriage?

[Pontius DIO]

T5 and T7 are different, but T7 head can fit a T5 block. The 2.3 T7 and 2.0 T7 head are the same head.

[jcm]

I'm sorry I missed your reply to my post P. Please help me better understand. If the heads are the same, I need only concern myself with the ECU controlling more volume from the 2.3 block. Can you shed light on this concern?

[Pontius DIO]

If you mean you want to swap in a full T7 b235r, you'd need to have the ECM flashed to change timing and fuel. Should be straight forward. I've been considering the b234r (T5 block) with a T7 head myself. Figure doing the swap and some mild porting to the head, turbo's exhaust housing, port blending anything off, would net an extra 20-40 HP over a bone stock T5 2.0L in NA form (meaning I'm not including the HP the turbo would add). Add some better custom cams from an aftermarket company could probably add another 10-20 HP for the entire RPM range.

[BobSaabit]

Pontius:

The T5 cams in a T7 will add a rough 10HP but mostly top end according to the gurus. I believe the other aftermarket cams are similar - more top end than the bottom you are looking for

[Pontius DIO]

Originally Posted by BobSaabit

Pontius:

The T5 cams in a T7 will add a rough 10HP but mostly top end according to the gurus. I believe the other aftermarket cams are similar - more top end than the bottom you are looking for

If I go with custom cams, they'll be made for mid range, with low end being the secondary goal. You can call places like Comp Cams, tell them the weight and gearing of the car, the usable power band you want to operate in, as well as the compression ratio, etc. and they'll come up with a grind that'll have necessary lobe separation, lift, duration, etc. I think most guys decide to get higher RPM's with a custom grind, which would favor turbos that breath more on the top end, which I'm not interested in.

What makes most RWD V8's fast is they make lots of torque in the lower RPM's, and keep making it through the rev range. This is what I'm trying to copy. 95% of my driving is below 70 MPH, so I want the HP/TQ to come on as early as possible. I've looked at DYNO sheets where one of our cars makes literally nothing until 3500. It might make a peak of 400HP @6500, but it's a dog where it counts. I know my 168k mile cams are not the same spec a set of brand new never used T5 cams have.

Lots of people dismiss the little things that make HP in favor of a 1 size fits all HP maker which sacrifices too much for a daily driver. If a T7 head adds 10 HP, and I can get cams to add a total of 15hp/15tq to the entire power band (or maybe a couple more hp/tq depending on how the turbo likes it), and lets say another 5hp/tq+ from porting the head, manifold, etc.etc then it'll be worth it. Considering the car was out pacing mid 13 sec cars on 16 PSI with no ECM tune, worn out turbo, mild pipe porting, weight reduction; adding a tune, the larger compressor wheel, another 4-9 PSI, head + port work, cams, pulling another 50 pounds out; I'm oh so close to the mid/low 12's Even if it's 60' is horrible at that power level until the suspension work is done, it should act like a 320-350hp V8 in a sub 3k pound car, with a nice strong torque curve. Add a 100-150 shot of puff gas and it'll be an 11 sec DD with full interior

[ZaphodB]

Quick question.. where did the 2.3 litre bottom end originate? if it's from a non turbo car you will need new low compression pistons for it or limit the boost to 6 PSi or possibly less