Build 3.0 or 3.2l for boost?

[elijahcole92]

Hey guys,

I recently picked up a 3.2l longblock from a wrecked car and I'm trying to find out what the pros and cons are of building it compared to my 3.0l

I'm switching over to a custom turbo kit I made and would like to push 500-550 on 93octane + meth.

So few questions:
1. I know the factory 3l isn't good for more than low 400s what about the 3.2?
2. Are the heads interchangeable between the blocks?
3. Other than being bigger displacement are the sleeves or anything stronger on the 3.2?
4. Are the bigger intake valves on the 3.2 worth any noticeable gain?
5. Will a built 3l rev be able to safely rev higher than a 3.2?
6. Should I build the 3.2 or my 3.0

 

[drmikey]

I know we've already spoken but I'll state what I know to the best of my knowledge:1.

I dont think the 3.0 or 3.2 liners will be the issue with big boost, it will be pistons and rings which I think will be the same between the two. AMW In finland says you can run 450-500 on a low pressure 6psi setup no worries.

2. Ive heard different stories. Reliable contact in Japan has said that the valve angle is different and on built motor may be an issue with contact. But Jeff at SoS says it will be OK

3. No differences other than the liner coating (Im not sure if the 3 or 3.2 has any differences in liner thickness)

4. Any increased flow has potential to enhance performance with the correct cams etc. But you can enlarge the intake valves on 3.0 at quite small cost

5. No difference in revving as the stroke is the same

6. The big question - AFAIK no one makes FRM compatible pistons and rings for the C32. Even if they did likely to be stock bore as I dont think it is possible to rebore and hone an FRM liner (not without very specialised equipment)You could build your 3.0 at less cost than the 3.2. The 3L would just need an overbore to 90.5mm and a hone. Very cheap to do - set of low comp pistons and you are away.To reliably build the 3.2 you would need Darton steel liners which increases the cost somewhat. And then if there were any advantages of Darton liners you could do that to your C30 anyway - as if fitting Dartons - the core of the C30 or C32 are machined out anyway

 

[Mac Attack]

I'll take a stab at question 6:

Either engine can make 550 HP (wheel HP I assume). The question is how long do you want it to last? If it's a reliable 550 WHP, then you'll be spending money on sleeving the block (either engine), new rods and pistons (either engine), possibly new main caps (either engine), and new HG's (either engine, but this is cheap). The other stuff like engine O-ring kits, bearings, TB, TB tensioner, WP, ARP gear, Timeserted block, refreshed heads, etc are things that would cost the same with either engine.

For a still lowly 550 WHP, there shouldn't be any noticeable advantage going to the 3.2L heads.

I'd say build the 3.2L while you enjoy driving your car, then swap engines later and add the turbo. If something happens with the 3.2L, you can still put the OEM engine back in and have the car worth more to a potential future buyer.

Not to be a prick, but there have been a lot of threads on here over the years asking the same as your questions 1 through 5. There's a lot of info available :smile:

Good luck with the build!

 

[E-Nough Logic]

Stock to stock the 3.2 just has the displacement advantage but beyond that it isn't any stronger. The FRM sleeves are stronger but thinner so that may be mostly a wash. I would and am currently building a 3.2L Sleeved C30A. 93mm C32 sized pistons, C32 sized valves. The only consideration the C32 may have once build would be the cams. I would image the 3.2 has large cams? Anyone have the specs off hand?

 

[Valhalla]

And don't forget head bolts. The C32 has a weakness and is known for pulling bolts out of the block. If you are going C32, you will be doing timeserts. Sooner or later....

 

[RYU]

Honestly speaking.. here's my take FWIW.

Sell the 3.2L. It's worth more to someone stock than it being built. Parlay the money into a 3.0L and build that instead.

p.s. Hope you took the 6spd also but it's a generally accepted rule of thumb here that the 5spd can handle 500wHP+ better than the 6spd.

$0.02.

 

[Jinks]

^This...
There are hundreds if not thousands of 3L engines out there with far less 3.2L motors according to sales figures. It makes purchasing parts more obtainable. Also once you bore a 3L you're just a hair shy of a 3.2L motor anyways and the power yield between the two is very minimal in my opinion.

 

[peiserg]

3.2 worth way more. Sell it, fund your project. Also, a 3.2 much harder to source parts on. Ive got a 3.2, and its been an issue occasionally.

 

[scammy]

Hey guys,

I recently picked up a 3.2l longblock from a wrecked car and I'm trying to find out what the pros and cons are of building it compared to my 3.0l

I'm switching over to a custom turbo kit I made and would like to push 500-550 on 93octane + meth.

So few questions:
1. I know the factory 3l isn't good for more than low 400s what about the 3.2?

• 3.0 better for boost because as mentioned head bolts pull in the 3.2 and use newer HG or comtec

2. Are the heads interchangeable between the blocks?

• yes but most upgrade to 3.2 specs with different make valves etc

3. Other than being bigger displacement are the sleeves or anything stronger on the 3.2?

• 3.0 stronger than the FRM

4. Are the bigger intake valves on the 3.2 worth any noticeable gain?

• Yes but for FI maybe not much

5. Will a built 3l rev be able to safely rev higher than a 3.2?

• same it all comes down to valve train and intake, however because of bolts pulling 3.0 maybe handle it better

6. Should I build the 3.2 or my 3.0

• build the 3.0 sell the 3.2

as others have said see my comments in your quote

 

[scammy]

Stock to stock the 3.2 just has the displacement advantage but beyond that it isn't any stronger. The FRM sleeves are stronger but thinner so that may be mostly a wash. I would and am currently building a 3.2L Sleeved C30A. 93mm C32 sized pistons, C32 sized valves. The only consideration the C32 may have once build would be the cams. I would image the 3.2 has large cams? Anyone have the specs off hand?

same cams unless auto

 

[scammy]

And don't forget head bolts. The C32 has a weakness and is known for pulling bolts out of the block. If you are going C32, you will be doing timeserts. Sooner or later....

correct ask Coz he swears by building a 3.0 over a 3.2 because of this

 

[scammy]

I know we've already spoken but I'll state what I know to the best of my knowledge:1.

I dont think the 3.0 or 3.2 liners will be the issue with big boost, it will be pistons and rings which I think will be the same between the two. AMW In finland says you can run 450-500 on a low pressure 6psi setup no worries.

2. Ive heard different stories. Reliable contact in Japan has said that the valve angle is different and on built motor may be an issue with contact. But Jeff at SoS says it will be OK

3. No differences other than the liner coating (Im not sure if the 3 or 3.2 has any differences in liner thickness)

4. Any increased flow has potential to enhance performance with the correct cams etc. But you can enlarge the intake valves on 3.0 at quite small cost

5. No difference in revving as the stroke is the same

6. The big question - AFAIK no one makes FRM compatible pistons and rings for the C32. Even if they did likely to be stock bore as I dont think it is possible to rebore and hone an FRM liner (not without very specialised equipment)You could build your 3.0 at less cost than the 3.2. The 3L would just need an overbore to 90.5mm and a hone. Very cheap to do - set of low comp pistons and you are away.To reliably build the 3.2 you would need Darton steel liners which increases the cost somewhat. And then if there were any advantages of Darton liners you could do that to your C30 anyway - as if fitting Dartons - the core of the C30 or C32 are machined out anyway

TODA state their pistons are compatible with FRM lining Mike, and yes you can hone the liner but you do have to have the new equipment that is now available we are going through this now with a 3.2 rebuild. We will have more details soon on our experience also anyone that has built and tested believe 450hp is as much as stock can handle without other issues else ware

 

[sca037]

As to question 5, I would use a 3.2L crankshaft in your build since it oscillates less at redline (resonance frequency is well over 8K rpm).
You have probably read about 3.0L oil pump gear failures, I'm pretty sure that's due to crankshaft movement at high rpm's....
We used a 3.2L crank in our 3.0L (OK, now 3.1L ;-) purple car's turbo engine rebuild and couldn't be happier with the result (currently @ 619whp).

Brian

 

[peiserg]

As to question 5, I would use a 3.2L crankshaft in your build since it oscillates less at redline (resonance frequency is well over 8K rpm).
You have probably read about 3.0L oil pump gear failures, I'm pretty sure that's due to crankshaft movement at high rpm's....
We used a 3.2L crank in our 3.0L (OK, now 3.1L ;-) purple car's turbo engine rebuild and couldn't be happier with the result (currently @ 619whp).

Brian

only 619 rwhp? how positively pedestrian you need to step up your game lol

 

[Mac Attack]

Well, it looks like I'm in the minority on this one.

My recommendation was based on the need to sleeve either block for your power goals. If you have a pristine car and want to maximize it's value, then build the 3.2L and save your stock engine to someday have a "numbers-matching" car. That's a big deal with older cars. For example, on one of my Chevy muscle cars, having the correct unmolested engine raises its value by a good $50k compared to another similar vehicle that may not be "numbers-matching."

If the rest of your car is in "good" condition and can be returned to stock someday with minimal work, I would keep the stock engine in reserve. If it's down the path of no return (widebody, gutted, etc), then I would build the 3.0L.

 

[elijahcole92]

Thanks for all the posts. Confirmed some thoughts I had! Going to sell the 3.2 and use the 6 speed I believe. If I was to keep my 5 speed I'd need to rebuild it and do short gears which is close to what I paid for the 6 speed haha.

So at what point are sleeves necessary? Was already planning on doing rods and pistons, oil gears, arp everything

 

[v8killer]

I cracked a stock cylinder sleeve at the 528rwhp mark. This was a SOS stage 1 build with forged pistons that went 27k miles and 6 years. I sleeved it after that.