3.1 cost

[Jojoz]

The more I read, the more I toss back and forth the 3.1 vs sbc.

 

Can anyone who has done the 3.1 stroker, give me an idea what their approx cost ended up?

 

I am in Aus and from the searching and pricing I have done, it is comparable to do the sbc conversion.

 

I have a 73 240 with an L28 under the bonnet.

 

Please, opinions welcomed.

[Shuyun]

3 to 5 thousand US depends a lot on what you have and what you need.

Do you have a LD crank

Do you have a set of 9mm L24 Rods

Do you have a source for custom Pistons

Do you have a machine shop you trust to do all the machine work on the block, crank and rotating assembly in you area

Do you Plan to assemble the engine your self

Do you Plan run carbs or fuel inject, Turbo?

 

All of these questions have been toughly covered in various threads.

The crank can cost form 150 to 450 depending or how you get it. New they can run 1200.00 This is an example of how what you want out of the engine when finished is very important to the project decide what you want plan how you will get there and double you projected budget.

[OlderThanMe]

If you buy the whole LD28 engine for the crank you can probably sell off all fo the other parts to actually make a little money from it.

[1 fast z]

Cast pistons, cheap bearings, cheapo machine work, parts and all would be about 3500.

 

Forged, good internals, GOOD machine work and head work, 7-8 grand with labor.

[HizAndHerz]

I've had the V07 crank, 9mm L24 rods, cast KA24 pistons, F54 block, Nismo timing set, new oil pump, new water pump, rebuilt damper, ported/rebuilt P90 head, ported intake with 60mm throttle body, MegaSquirt-II all sitting in my garage for almost a year. I haven't done anything with them because I'm under the impression from reading the forums that it'll still cost another $3000 in gaskets, bearings and machine work, even if I assemble it myself.

 

It just ain't worth it. I'm pretty sure I'm about to give up on the whole idea even though it seems I have 95% of it staring me in the face. Very depressing

[garvice]

Mate,

 

As cool as it would be to have a L31 (I would love to stroke my turbo L28) it may be better to build an RB30DET. We live in aus and these blocks are cheap as chips here (because of all the beven/bogan (americans read this as hicks or rednecks) and there love for commodores).

 

The RB26 head bolts straight on.

 

This would be my choice over the SBC, just my opinion though, sorry if I got off topic.

[Daeron]

Mate,

 

As cool as it would be to have a L31 (I would love to stroke my turbo L28) it may be better to build an RB30DET. We live in aus and these blocks are cheap as chips here (because of all the beven/bogan (americans read this as hicks or rednecks) and there love for commodores).

 

The RB26 head bolts straight on.

 

This would be my choice over the SBC, just my opinion though, sorry if I got off topic.

 

seriously, i was gonna say the same thing.

 

beven and bogan? like, rhyming with seven and logan right? crazy.

[greenmonster80]

I spent just under 10K putting my L31 together. Granted I could have cut costs. KEW timing and ITB'S were not necessary. Stock timing set and triple carbs would have knocked off little more than half. I agree that being in AUS a Rb30 would be the reccommended way to go but I do love my L6.

[RIP260Z]

As already said, it can be cheaper if you do it yourself, but don't expect any great hp/torque numbers. The component short block parts were not designed to work together, so its the putting the engine theory/machining and assembly together that makes it work, either with a good machinist or assemlbler, or both.

 

What has not been mentioned, is the work/cam that needs to be done to the cylinder head to make the sort of power a stroker can produce.

 

If you want to go the 3.1 route, expect to throw some LARGE amounts of money at like Greenmonster80 has (and so am I [KEW timing and Dellortos]). There are other ways as have been suggested that will be cheaper.

 

Just my thoughts.....

[OlderThanMe]

As already said, it can be cheaper if you do it yourself, but don't expect any great hp/torque numbers. The component short block parts were not designed to work together, so its the putting the engine theory/machining and assembly together that makes it work, either with a good machinist or assemlbler, or both.

 

I would have to disagree with the first part. just look at Big-Phil...

He built his own motor(s) on a tight budget and made 20 PSI of boost on stock pistons. DIY is definitely the way to go. Just find a competent machinest to do the work for you that you can't do.

 

I'd rather know how my motor was assembled then have a mystery box in the car that you don't know about.

[HizAndHerz]

If there is anyone out there that has done a budget stroker build, sucessfully or otherwise, I'd sure wish they would chime in. In all my searching, I haven't been able to find anyone on the forum who built a budget stroker.

 

...just look at Big-Phil... He built his own motor(s) on a tight budget and made 20 PSI of boost on stock pistons. DIY is definitely the way to go. Just find a competent machinest to do the work for you that you can't do.

I would like to believe that the same method could be applied to a stroker. You'll often read on the forum that for the bang for the buck, there's no comparison between a stroker and going turbo. Phil did a lot of the work himself and used throw-away blocks but he's blown his engine at least twice. He's okay with that since his goal was to get all the externals working and use a low-budget bottom end to have some fun. That's very different than pouring all the money into the internals and having major machine work done for a stroker.

 

So, what really are the extra machining costs involved over a standard engine build? Boring the cylinders over .120 and having the flywheel, crank, rods, pistons balanced individually, then as a whole? If so, assembling the bottom end is not a DIY job.

[OlderThanMe]

So, what really are the extra machining costs involved over a standard engine build? Boring the cylinders over .120 and having the flywheel, crank, rods, pistons balanced individually, then as a whole? If so, assembling the bottom end is not a DIY job.

 

 

Boring an engine over should be the same cost no matter what bore you want. You may have to do it anyway on a rebuild.

Stroker crank USUALLY goes in with no preoblems. Some L28 blocks have to be clearanced though. You can check the oil clearance on your own with some plastiguage before going to the machine shop so you won't get any suprises.

You can do most of the balancing yourself. Just need a balance or an accurate digital scale. For the rods you just need to make a jig to hold the rods for measuring the weight on each end.

The flywheel and crank you can't really do. You can polish the crank though.

 

Buy an entire LD28 and sell off the parts to the diesel guys...they pay for the stuff. That leaves you on top for the crank rather than $400 in the hole for an ebay crank.

 

The 9mm bolt 240Z rods you can find in a junkyard usually for a good price.

 

The pistons will probably cost the most as being forged slugs and probably custom to get a nice dish to match your combustion chamber.

I could probably get all the parts for a stroker L28 shortblock for around $600 after you sell off an entire LD28.

[DHale_510]

There are three more or less equal parts to consider;

1. The short block has been well discussed. Figure $500 to $2500 depending upon what you want to rev to, and of course the resulting power. The $500 short block is maybe a 200hp set up. Maybe.

2. The cylinder head is a big deal. Pretty much any stock head will only flow about 175hp. If it is well assembled. Porting, big valves, and such can double that, but again the price varies. Figure about $500 to $2500 again. Some of us have spent more....

3. All the other stuff. SU carbs will work up to about 200hp. Maybe. Factory FI maybe 225hp. DCOEs and the like take you to about 250hp. Fancy FI setups go to 350hp. Ignition setups enter into it too. No stock setups really work with a 3 liter setup. Too much advance, too quickly arriving. A 200 hp motor will work OK with stock electronic distributors, but that fancy 350hp beast must have a fully setup crankfire unit. Any motor will benefit from a well tuned ignition, they all require custom tailoring to get there though. Say expensive dyno time.... That familiar $500 to $2500+ budget arithmetic has come back again.

I wish I could have kept my 350hp 3.2 under $7500. I "started" with that budget, plus I already had the new crank and an expensively ported head, fancy pan, carbs, etc.. I guess somewhere in there I still managed to double all of my budget allowances. But then isn't that a normal deal in this hobby? Set a budget and double it....

 

Since you asked......

[JMortensen]

I think it is possible to do most of the expensive stuff at home. The work that I had done at the machinist was: 1. Hone the block 2. Balance the bottom end. 3. Valve job. 4. Install 280 valves in the E31 and port the bowls to match. That was it. The rest I did myself.

 

You might not get all 10/10ths of the potential power out of the head, but you can easily get 8/10ths, and maybe more if you take your time with what you're doing. The engine I built in my garage is a 2.8, I had larger valves installed in the E31 and the machinist smoothed out the bowls when they installed the larger seats. I did all the rest of the headwork, unshrouding the valves, cc'ing the chambers, mildly reshaping and polishing the chambers. I did a little work on the short side radius and cleaned up the casting marks in the ports, but the ports are basically stock diameter. I also port matched my Cannon manifold to the head and tuned my Mikunis with a narrowband O2 sensor. I did some work to the block polishing and notching it so that the unshrouded area of the head matched the block, giving a nice area for flow around the cylinder wall side of the valve at higher lifts. I chose a cam that is really too small at .490/280. This engine makes about 240whp. I didn't bother with a flowbench although I did find DIY plans to make your own, that was just too much work for me to justify.

 

It is also necessary to keep in mind that Dennis is talking bhp when he says 350 hp, and most people will put hp in terms of whp around here. So if you take my 240whp for example and add 15% for drivetrain losses (I know that's not accurate, might be high or low, but this is just an estimate) you get 276hp, and then size the engine up to 3.2 (+12.5%) you get 310.5 hp. Maybe not the whole 350 that Dennis got, but I spent about $2500 total and got roughly 88.7% of the power per liter that he did.

 

Just out of curiosity Dennis, how much power do you think Larry Butler's L18 is making? I know it's not making what Pinky makes, but he ported his own head and built his own bottom end too, and it's not slow. I think Cary built his motor too. DIY doesn't necessarily mean crap.

 

On the other hand, we had a member zredbaron, who built a stroker and put down 157whp: http://forums.hybridz.org/showthread.php?p=458664 and then he had Sunbelt build him a head with all the cool stuff for $3K and he put down 197whp afterwards. My impression of his problem is that his 40mm carbs are holding that motor back, maybe his flowmaster muffler too, but those are just guesses really. His example does prove that you can have a VERY nice head and crankfire ignition and and still not make power if the induction is not optimal.

 

There is no magic bullet, other than sending an engine to Rebello or Sunbelt with a blank check and asking them to make it the most powerful engine on the block. Dennis can do that but most of us can't. That doesn't mean that we have to suffer with no hp though. You just have to be creative and willing to put some man hours and elbow grease into it.

[randy 77zt]

how hard do you want to work-how dirty can you stand to be?the local pick&pull is where i score my parts.i paid $200 for my diesel crank but that was in a short block that i had an apprentice pull and bring to the dealership where i worked as a tech.the apprentice made $80 for the pull job but to me it was worth not rolling on the ground at p&p.i stripped the crank out at work and avoided the greasy mess at my house.my l24 rods were pulled by my-i found a 810 with head allready pulled so i pulled the pan and got the pistons &rods.my pistons are 87mm vg30dett donated from member 510six.my machinest bushed the rods -the vg pins are 1mm bigger.my machinest bushed the rods,bored out 1 of my l28et blocks,balenced it,hottanked it ,assembled short block for $500 cash.so i probably got $1000 or $1200 in a 3l short block.if you just throw out your credit card somebody will be there for you.if you can load up tools and go out to local pick&pull you can save money.its all up to you.

[Jojoz]

Thanks everyone for the input.

One train of thought I have had is if I go and work my l28 to make some high bhp, how reliable and what life will I get out of it, as opposed to a shelf LS1. That rb30 bottom end with the 26 head sounds good though.

 

I am also cursed with the all or nothing bug.

Either way I go, it's going to hurt my pocket.

 

I really wish I knew someone that had the L31 over here so I could give it a run, just to experience it and get a better idea of what outcome to expect.

[JMortensen]

L28 vs LS1??? No comparison. You'll make buttloads of power with the stock LS1 and the L28 (or L31) will be pushing it's max to make the same hp number. Once you start looking at the torque and hp curves, it becomes immediately apparent that the LS is going to have WAY more power in most of the rpm range, and the torque curve on those suckers is flat as a pancake. The LS is also capable of a LOT more power with a couple simple tweaks like a cam swap and some valve springs to complement it. There's just no comparison if you're looking for max power output.

 

If that's the decision you are trying to make, L28 vs LSx, you really should do a LOT of searching and reading before you decide. They're SO different it's hard to understand why you would compare those two engines, had we not known that this was going into a Z that is...

[Jojoz]

Jon, I think I'm trying to justify going the LS1 over tinkering with the L28.

Nothing wrong with the L28 I have, but bit of extra punch could be the go. Maybe just turbo and get some nice efi rather than go all out.

[JMortensen]

You're asking the wrong guy I guess. I'm ditching my L ASAP for an LSx instead. I'm tired of trying to squeeze blood from a stone and I'm not a big fan of turbo lag.

[speeder]

I keep hearing people talk about how expensive an L stroker is to build and will submit this and shut up:

 

Over the cost of a proper performance rebuild, the stroker is going to increase the money spent only by the cost of obtaining the crank and rods, plus the slight cost of block clearancing( if required). This assumes that the builder is upgrading pistons, building a performance head, and upgrading the fuel system to support the desired power level. The rebuild process, including boring, balancing, and setting bearing/ ring clearances will otherwise cost the same regardless of the crank and rods used. So being a stroker isn't the issue. Being an L is.

 

My 430 whp 3.0L turbo stroker L's long block cost about $4000.00, excluding turbo and fuel management hardware. I would probably not want to add up my costs for that stuff.

 

I'm sure building an RB30 would be cheaper in Aus.- Less machine work required for a hybrid built with compatible components, and probably little or no head work needed to get comparable power to the L31.

 

This said, talking 275 or so reliable and streetable whp , there is probably no argument that an LS1 would be the cheaper route to the same number.

But, as Jon said, a torquey V8 would have a very different feel than a high revving L6. This dynamic, with cost considerations, is very individual choice.