Who has the best 3.4L conversion ?

There are now a few choices out there for enlarging the 308 engine to 3.4L (or some other displacement). It seems like several owners/members here have had it done. I am sure others have checked into it. Based on experiences and specifications, what is the consensus on who has the best overall approach an why ???

The following factors are relevant ----

Performance
Reliability
Quality of workmanship
Quality of parts
Total cost
Turn around time
DIY options for some of the labor
Availability of parts
EFI compatibility (if added later)

 

Newman is hands down doing the best 3.4 QV engine ever done. No question. It will push 400bhp at the flywheel when done.

For 2v carb engines I believe I hold the known bhp record as neither of Paul's have been to the dyno although I believe they would undoubtedly equal mine. I have a very reliable and street driveable 272bhp at the wheels with 225lbs tq. That's about 330bhp at the flywheel. Carobu's 2v carbureted engines came in at about 280bhp at the flywheel.

Nick's 3.5L 2v engine is on another planet, huge amounts of head porting, very custom cams, ITB injection, it's very impressive making probably around 380 or so bhp at the crank with a vast amount of torque, probably around 300lbs torque.

 

Since this is becoming a known practice. What is the cost associated with this project?

 

Carobu does a 3.5L conversion not a 3.4L. The 280bhp comes with 250 foot pounds of torque and is for stock injection on a 2 valve with very mild cams. If you have a 4 valve, the numbers go up because of better flow through the heads. If you convert to EFI or have carbs, the numbers also go up because you can use more aggressive cams. Carobu has done several 4V cars with EFI that came up with over 345hp at the fly wheel. The torque doesn't go up as much though and peaks around 265-270 foot pounds.
Make sure you are comparing apples to apples when looking at who is doing what.

 

Carobu starts at $25k but is time and material. The cost can go up if you need extra work.
Nick's is considerably more expensive. He probably has $20k+ in machine work alone on his heads but no one can touch his performance.
If you do everything yourself and send your block to Steve D. or someone, you can probably get away for under $15k.
I called Norwood and asked them how much they charge and I can't honestly remember. Though I do remember the guy on the phone telling me to just buy a 355! He makes a good point unless you just HAVE to have a 3x8.

 

well, I'm a bit biased as I do the assembly and engineering for Nick, though the 3.5L project was before I was doing anything with Nick. however it's an apples and oranges comparison. While I have no direct knowledge with Newmans work from what I've seen posted and from second hand info from people I consider knowledgeable and trustworthy, he does good work and puts attention into what he does, looks nice and pretty too And he works in the snow, crazy Canadians! probably plays in it too...

given that there are many ways to skin a cat or re-build a 3x8 motor it really comes down to what one is looking for.

I can really only speak to what I do for Nick,
The block is machined and new custom liners are installed by THE man and legend Steve D. I use new custom made rods, custom pistons. head work is per request, so anything from mild to wild. same goes for intake plenum and fuel management.

I don't have a 'production' type of build, no two are the same so it's difficult to compare directly the build options between those of us who do this.

I'd also like to submit that there are many times I really question my sanity doing this, there is next to no money in it after you factor in the time involved and the surprises one may find in a tear down, parts sourcing and/or fabricating, etc.. I like it though, the challenge and the unique opportunity to build something that causes gear heads to pause and go oooo nice, or even the occasional, have you thought of.... and the favorite, can you do this? it's this or go back to the DoD...

there are few things that in my opinion I do not make exception on, Steve's liner work, new rods and larger gudgeon pin dia. the reason for the liners is simple, Steve's experience backed by results have proved that it works without worry. the larger bore dia and increased loads on the piston absolutely require an increased gudgeon pin dia, and new rods also utilize far superior bolts that I don't have to worry about letting go at 9k+ rpm.

As to HP/TQ, the 4v will outperform the 2v every time, it has better head flow. the 2v just doesn't have the ability to support 400hp due to the head flow problem in NA form.

Now if our old buddy the infamous MarkE ever got into doing rebuilds and out of his basement, I'd quit, I don't want to compete with him, he's too nice and waaaay over educated/qualified.

And now the all important tag line in racing,
Speed costs money, how fast do you wanna go?

 

exactly!, for the money on some of the builds you could go buy a 355/360.

Nicks 2v heads had an amazing amount of work done to them to get the most flow possible out of them, shim under bucket, Ti keepers, locks, custom springs, custom valves, custom massively aggressive cams etc.. obscene the amount of time and effort put into them really, don't get me wrong, beautifully done though.

I think the least amount one would spend all done soup to nuts is around 20~25k, parts keep going up. and you don't want to overlook the gearbox and clutch when pushing the Tq envelope.

 

Mark E did Rob's (Crowndog) heads which Paul has now. The flow they yield is absolutely nuts, I couldn't believe what I was hearing regarding those flow numbers, it's just bananas. Hence why this build Paul is doing with those heads will just be on another planet lol. Lots of lift from the cams too, the engine will be certifiable *insane* for what it is. The only thing that would push it into the really really nuts category would be if Mark built a ITB manifold for it too.

And yes, you're absolutely right, this stuff takes a huge amount of time. Labors of love more than anything else it seems.

 

I remember Black Horse Motors in LA had a project few years ago, a 308 with a 355 motor conversion. I believe the car is up and running well. I think this would be a good upgrade without the turbo.
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Sheesh... That looks like quite a machine! Definitely the stuff daydreams are built from... Of course, in my daydream I would have taken the time to find a GTB to stuff all that horsepower into...

 

2V right? I honestly haven't looked, I know Mark has been doing some heads and couple things here and there between his own projects and the honey do list.

Yeah the time is downright depressing, even if I wanted to there would be no way I could build every ones motor, it's take yrs heck maybe decades. you practically have to get the planets to align and have everything on hand before you start while knowing every contingency and also request zero further input from the customer to get a build done 2~3 months. and I'm not talking a freshen up build but a strip down to bare and remove and inspect every single insert, clean and chase threaded holes, esp those blind buggers. re-install with proper lubricants per the spec for the application, disassemble again checking clearances, re-assemble, rinse repeat. etc.. clean up, take pics, write down notes, fill out binder for notes. of course an apprentice would come in handy for that stuff, you know a tall leggy women that might be a bit top heavy.... course the wife never seems to agree with that one.

right now is the busy season for a lot mfg in the aftermarket auto world, rods are 12~18wks lead time, pistons now stretching into 6wks, and on and on.... winter is a great time to get this stuff done but most people seem to not want to and wait till spring/summer when it's near impossible to do in short time frames.

 

Nope, Mark did 4v heads. They flow like crazy.

 

How much does a drop out 355 engine go for?

These projects are awesome. If money was no object.... Drool!

Realistically us poor guys should focus on weight reduction. Lose the AC, heat, shave weight everywhere possible and "feel" faster.

 

SCOTT (or anyone else who might know) ---

I have heard that both a 355 and a 360 crank will work (with some mild modification, I would assume) in a 308 block --- is that true --- I further assume the bore centers match up ??

If so, I wonder how feasible it might be to machine a 308 block to accept stock 360 liners (the liners would have to be shaved I am sure), and then install stock 360 pistons, rods & bearings (along with the crank, of course) ? If this could all fit without the pistons decking out, the resulting compression ratio not being crazy, and enough liner wall thickness leftover to be viable and allow adequate cooling........hmmmmmm.......there are a fair number of used 360 engines out there for not a whole lot of money .

Probably it would not run too well with the stock 308 CIS and ignition, but add an EFI kit......get it mapped properly........and......

 

the cranks from the 308 thru to the 360 all share the same bore center and bearing dia, i.e. they all drop in fine. the issues vary, the 348 & 355 do not use flywheels but a splined input shaft to the gearbox. the 360 offers the best bang as it does utilize a flywheel and has all the proper machining for the pilot bearing and bolts. there is the need for a spacer since the 308 is not dry sump, pretty simple fix. I don't see the advantage to using the 360 liners, costly and if your stock liners are good just go with new pistons, I highly recommend using the 360 gudgeon pin dia though. the need for new pistons is due to the increased stroke, the deck clearance changes so a new wrist pin deck height is needed. now what you do for cams and lift will also effect the pistons as well.

Ferrari did not change a lot over the models, even the 360 waterpump housing will bolt the 308 block. the basic block architecture remained the same till the 430.

 

Excellent thread guys; Now lets add one more twist.

Who does the best dry sump conversion for these high out put engines in the traditional, transverse 308/328 position? Case conversion and factory like chain drive, external belt drive, or external electric pump? Who does the best oil pan and sump conversion pieces?

 

$25,000 for 100 more hp?

 

Yep and more importantly about 100 more pounds of torque (with a flat torque curve!). That is what is really missing on these cars and that is where you really get your improved feel.
Unless you do this yourself like FerrariPilot, there isn't any cheaper way that I could find.

 

Wish it were so!

 

ditto

 

After getting the price to stroke my QV to 3.9 I decided a stock 308 was the way to go until one of Mark's old SC "kits" showed up.
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Only conversion to chain drive I know of is this one:

Osterroth-Engineering Ferrari Alfa Romeo

But it is not available anymore, at least for the time being.

Rgds

 

The 3.0 litre 2 valve running on Weber 48 IDF carbs in my 308 GT4 racer makes an easy 380 flywheel BHP . CDi ignition and Motec management control it all . I have a 360 crank and steel rodsto take it to 3.3 litres and it should make 410 plus on carbs and I expect 420 plus on 50mm ITB's . The shop building my engine have a larger capacity engine in build , still on 2 valve heads and carbs so I will try and get more info and photos as they expect great things from it.
Here's a picture from a while ago of me hunting down a 512M at Brands Hatch !!
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I bought a 348 engine with the cambelt snaped (heads are total loss) to tune my 4v 308 engine.
I'm planning to use the 348 liners,rods, pistons, cranck and the cams on my already flowed 308 heads and then put it on 44dcnf carbs with black stallion ignition also with the superformance light weight flywheel with dubble splitted clutch and short ratio drop gears.

That is my plan!

One of the troubles is that the studs are not easy to remove in order to get it drilled for the 348 liners.
2nd problem is that the liners are different to the 308 ones.
In order to solve that problem the block should have a full centimeter removed on top in order to match the 348 liners.
brings me to problem 3; with a 'shorter' block i will have to see for an extra belt tensior or something that can make the 2cm shorter turn right (1cm up, 1cm down)

That is what i'm suffering right now. My uncle is busy to get the studs out, from there it can be drilled and shortned at the machinestop...

advice or pointers on my project are welcome!

 

Wow I would love to get my hands on an IDA manifold for a 2v head. Let me know of they're available! Would love to see a pic of that setup. Impressive.