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Posted by: Mikey914 Nov 30 2021, 11:27 AM

Looking to make a larger motor (4) planning on a 2665, as I don;t really want to go over 103mm to make cooling easier.

The 80 crank is available for stock rods not the Chevy rods. It is my understanding that the Chevy option offers a significant upgrade to the strength. I'm tempted to do the stock.

My question is : should I wait an indeterminate time for the crank with the Chevy rod option? What am I really loosing here? or is this just a must for the larger motors?

My 1st engine build.

Posted by: VaccaRabite Nov 30 2021, 02:22 PM

What are your goals for the motor? Long drives, or short? Track use vs street use. Do you care if its somewhat short lived?

You've been in the game long enough to know a lot of this, but heat is your enemy and the big motors can produce a lot of it.

Zach

Posted by: 914_teener Nov 30 2021, 04:07 PM

I know it's not one of your questions but......

Just put in a six.

My 02.

Posted by: mepstein Nov 30 2021, 04:17 PM

You have a bunch of fours, time for a six.

Posted by: 914werke Nov 30 2021, 04:37 PM

Nickies?

Posted by: Superhawk996 Nov 30 2021, 04:55 PM

Seems like you're proposing a jump off the high dive, into the deep end, and planning to learning to swim once you're in the water.

Forgive me if that comes off as overly negative. It is not my intent to insult you by any stretch of the imagination.

You've asked a loaded question about big bore /4's which isn't an ideal build even or an experienced T4 builder. Not to mention the other aspects like rod choices, stroker crank, case modifcations, Nickies, RPM & inertia effects on the durability of a T4 crank and rods, etc.

I'm sure you can do it, it's not impossible. You just need to be aware of the negative trade offs associated with the big bore route and go into it with eyes wide open.

Posted by: Shivers Nov 30 2021, 05:34 PM

80 mm crank, wow lots of torque. In my bug days the chevy rod mod was popular with guys building drag engines. With a crank that big a little extra weight on the rod should not be a problem. Like said before heat would be my concern.

Posted by: NARP74 Nov 30 2021, 05:55 PM

I just went though this drill. Met a guy with all the parts to build a 2300ish engine, all the parts machined and ready to assemble. I decided it was not right for me and walked away, but your situation might be different. I can make a strong case for either side of the argument, just depends on your situation.

Posted by: Mikey914 Nov 30 2021, 08:04 PM

Well my buddy Allen who is a factory trained mechanic is going to help me assemble the motor. He was aware of the journal mod, but didn't think it was that big of a deal.
The issue is crank availability.

As far as heat and thermal build up. The consensus we came to was no larger than a 103mm on the bore in this configuration.

This motor will be utilizing heat dissipating and ceramic coatings, as well as some new biral cylinders we are working on.

It will have lots of sensors monitoring each cylinder for EGTs and multiple head sensors. We will be running fuel injection with a new setup that we are trying to make more plug and play for larger motors.

Will probably spend as much as a 6 when Im fone. But if it works as planned will be a blueprint for turnkey larger motors.

Posted by: NARP74 Dec 1 2021, 12:06 AM

Sounds like you are on the right track. Making it affordable, reliable and not needing a rebuild in 30k miles are the next big steps.

Posted by: BeatNavy Dec 1 2021, 07:15 AM

Just tell me when the group buy is scheduled, Mark

Posted by: Superhawk996 Dec 1 2021, 07:31 AM

Other big bore considerations beyond thermal effects:

T4 Crank only has 3 bearing journals to carry loads. Not ideal for lots of power reliably over long durations of time.

Rotating inertia of the crank increases as a function of mass and stroke^2 (exponential). Rotating mass and/or inertias may increase substantially due to bigger pistons and wrist pins, stronger rods, the added mass from the stroker crank depending on the components you use.

In addition to those inertial loads you now have more combustion based torque load applied to the crank with each combustion event.

Horizonallly opposed 4 cylinder engines - although they have perfect primary and secondary balance, the non overlapping combustion events contribute to torsional oscillation of the crank. Normally a harmonic damper would be used to damp these out. Not aware of a harmonic damper for T4's. The more power the engine puts out, the more quickly the crank will be fatigued by the increased torsional vibrations.

Posted by: Shivers Dec 1 2021, 07:40 AM

Have you considered a possible short stroke version, for people that like that type of power. A counter balanced 1.7 or 2.0 with 103's , a well breathing induction system
with the horse power a little higher on the band.

Posted by: Superhawk996 Dec 1 2021, 07:43 AM

delete - duplicated post

Posted by: Mark Henry Dec 1 2021, 09:03 AM

Toss the stock rod idea, they're heavy and a wider journal further weakening the crank. Chevy 2.0 journals and H beam rods are the way, one cam lobe where it meets the rod still needs major clearancing with 80mm. For longevity and an easier build I'd recommend the 78mm crank with type one journal size rods, the beefier T1 rod journal makes for a substantially stronger (less flex) crank.
Although there's no replacement for displacement depending on expectations I try to to talk peeps into a reasonable margin for safety.
My own engine (in a '67 bug) I built 78mm x 102mm (2.6L, nickies) mostly because I planned to put many street miles on my engine. When building my engine I had both a 78mm and an 80mm crank, I chose the 78 and sold the 80mm.

Biral cylinders...why?
Porsche abandoned biral's after only a couple years and LN found to make them properly they cost almost as much as nickies and also abandoned biral cylinders after just a couple of years. If the aluminum fins aren't perfectly (and I mean perfect) cast onto the steel it will have voids, at which point you may as well run no fins at all. LN found material separation to be be a huge problem in manufacturing. A china supplier working at a reasonable price point will fuch this up and a domestic supplier will be way too expensive. You will only be able to tell this by Xray and/or ultrasound of each and every cylinder further driving up costs.
I won't build a Biral cylinder engine (except stock 911), I don't give a flying fuch who made them. I'd rather walk away from the job.

For a street car my engines require a valve job at 60k and the bottom end must be good for 2-3 times that. An 80mm crank engine requires a full teardown at 50-60K regardless. The slightly detuned 2.6-2.7 engine is a much better overall investment.

Edit; Note the china cranks are softer than OE, I'm expecting that a full tear down of the bottom end will be required before 100K to check for center main wear.

Posted by: Jack Standz Dec 1 2021, 01:14 PM

Sounds like a very cool project. Best wishes with it. Similar to one we have planned.

Some things going into the 2.6 liter Type IV motor when time allows (so many projects to complete beforehand):

Type 1 Journal on crank - hard to find, but available 18 months ago when started assembling parts. Stroke is 80mm (78mm stroke crank wasn't available).

Nikasil cylinders with JE forged pistons, 102mm bore. Pistons are light, light lifters and valve train, along with lightened flywheel. Reducing reciprocating mass improves longevity, faster acceleration, more HP. Careful balancing very important.

Better than H-Beam rods (lighter and stronger):
https://www.thesamba.com/vw/classifieds/detail.php?id=2342801
EMPI New Pro Series I-Beam Rods 5.5 Length with ARP 2000 5/16" Bolts in a VW Journal. These are lighter and stronger than the H-Beam Rods.

Aluminum push Rods, custom length.

Type 1 tool steel lifters (lighter than Type iv).

Custom cam with extra duration on exhaust stroke (helps control motor heat). Lead time can be a project killer though.

Keep compression low to aid with heat control. Initial spark setting,to be 14 degrees BTDC, with 28 all in...subject to tuning and optimization. Probably starting with carbs because they're so tunable and easy, especially since the car is already setup for them. Maybe later, like you, it'll have injection?

As you already know, heat is an enemy in larger Type IV motors. So, stay focused on that (in addition to careful machining and assembly) and can't wait to see how she turns out!

Posted by: NARP74 Dec 1 2021, 01:23 PM

Did anyone consider getting this project going again?
http://www.914world.com/bbs2/index.php?showtopic=42456&st=0
Seems like some of the originals dropped out but might be salvageable.

Posted by: 930cabman Dec 1 2021, 01:38 PM

Posted by: Mikey914 Dec 1 2021, 02:19 PM

Thanks all,
This was the kind of feedback O was looking for. Definitely a few things to think on. We were looking at makung the biral cylinders here and had an idea for a twist on them that could improve cooling. I get that voids would be an issue. My idea was to utilize a process that we could replicate, and if the results were consistent, we would only have to to QC on a few in each batch.

The 78mm crank is a good point.

I think we can develop a pretty solid motor. The testing will be the most fun.

Mark

Posted by: 914_teener Dec 1 2021, 02:35 PM

Mark....

You are probably better off lookng at flame applied coatings rather than the biral cylinders.

There are some amazing thermal coatings out there now as I sure you are aware of being into aircraft.

This technology just wasn't as mature back when Porsche looked at it.

Kind of like the EV technology now....

Posted by: Mark Henry Dec 1 2021, 02:43 PM

My advice...don't. There's already too many players in that market.

Stick with your niche, if you need to expand cover the rubber/plastic (etc) parts for 356 and 911, venture into other cars, etc.

Posted by: NARP74 Dec 1 2021, 05:04 PM

New to the game here; so who are all of these players? I was just looking for them a while ago, needing a new or rebuilt engine. I found Raby, too expensive for me. I found some builders that went out of business. I found some builders scattered around the country but not convenient for shipping and expensive. I found a race shop several hours west of me, very expensive. I found one local builder that does a lot of VW stuff, he is booked out 6 to 9 months. And that has been the end of my work.

I am sure I have missed some. But from my perspective I would say go for it!

Posted by: barnfind9141972 Dec 1 2021, 09:39 PM

Everyone claims there’s tons of people who can take these jobs on until you look for them and everyone is too busy, too expensive, or ready to retire. The cars aren’t going away but the people who help keep them on the road on the business side seem to be

Posted by: 914_teener Dec 1 2021, 09:48 PM

I don't agree with Mark. I don't believe there are "too many people" .

What I believe is that things aren't like they were even 5 years ago. So to believe you can go down to your "local VW" shop and get a valve job for your 50 year old heads...have been gone for some time and since there is now a scarcity of people that are willing to take on that...the people that will, can't get paid what it is worth because it is "too expensive".

Try finding a really good used car now...strange times and they are a changing. I say go for it Mark...put something together....but good work and good engines have never been cheap.

That's the original purpose of this community to share experiences and experiment on your own and share them.....not as a social network to find who does work cheap.

Go for it.

Posted by: mepstein Dec 1 2021, 09:57 PM

There are probably reasons why the people go away. It's easy to love these cars but hard to make money on them. Money isn't everything, unless you are running a business and then it's pretty important. I bet there was very little profit from the $5K engine program so the builders moved on. Engine building, like all the other restoration projects, takes a lot more time than people realize. Not just the actual building but the initial customer consultations, parts purchase, engine tear down and cleaning, all the steps needed to get to the build, tuning and then the final steps to get the engine to the customer. It's a lot.
Then if the builder makes one mistake or uses a defective part, it can cost them thousands in time and money to make it good.

Posted by: 914werke Dec 1 2021, 10:47 PM

Posted by: wonkipop Dec 2 2021, 01:36 AM

actually thats true about the last 5 years.

its happening here too.
you want your 356 heads machined?
sorry. the good guy just closed. and he did. we just found that out here.
covid might have prompted something but it was going to happen?

it needs to get passed on generationally?

it will shrink for sure, the market.
but you are going to need someone or a few someone's who stay in the game.

so @http://www.914world.com/bbs2/index.php?showuser=3348 idea maybe is not so wrong.

but you are going to have to be good at it.
and i guess people are going to have to pay?.......

thats what i see ahead.

Posted by: Mikey914 Dec 2 2021, 03:05 AM

Well, I know for sure this is a long term project. It's not something I'm gonna get rich off of, nor do I really want it to be a cash cow. I'm interested to see what I can do here and play with some "improvements" I can make, then test them.

Posted by: Superhawk996 Dec 2 2021, 07:02 AM

Most "Automotive Technicians" are no longer mechanics and certainly not ones that have the tools or skill to do a valve job from scratch. Far too many are trained to simply depend on OBD dignostics and swap parts.

I know that is a unfair stereotype and there are still good mechanics out there. I don't mean to offend them. Even so, the "Techs" are generally better trained on how to diagnose and repair CAN related module and electrical problems than the historical mechanics so it really is a tradeoff that is a result of what they work on most and where they make their money.

For what it's worth, I thought Mark was referring more to the creation of big bore Biral cylinders and the associated manufacturing pitfalls of Biral vs. the tech that went into developing Nickies. Porsche didn't stay with Biral for long . . . there were good reasons for that.

Posted by: Superhawk996 Dec 2 2021, 07:06 AM

You forgot dealing with crazy customers. You know the kind.

They guy that has you rebuild an engine. Proceeds to miss a shift, over rev's it, and grenades it. Then sues the engine builder.


Yeah -- it happens. Sad state of affairs. But, explains why it is getting so hard to find a reliable engine builder.

My hat goes off the Mark and any of the others out there still making a go of it.

Posted by: Shivers Dec 2 2021, 08:24 AM

Just a thought from a guy that has to do his own work, to own this car. My last engine build I had parts from OC to Palm Springs being machined or made all together. Getting the (correct 1 over) bearing, gaskets/seals, shims (new 13 lb fw) You know how it is. But I was hunting the best part for the best price, that I could afford. I've seen engine build kits, gaaads. Just a thought

Posted by: Mark Henry Dec 2 2021, 08:42 AM

Yes I was talking about the biral's, I remember well when Charles (LN) made a go of them and the cost was too great to make an acceptable product to their standards. They had the product and all the manufacturing bugs worked out and they still decided to stop making them.

As far as building engines go... well have at it, good luck.
You might have some success if you're building a single stock engine line, but once into performance every customer has different needs and wants and no single engine line will satisfy every customer. I've personally never had much luck selling turnkey engines built on spec. other than stock engines.

Posted by: rhodyguy Dec 2 2021, 08:54 AM

Budget in brand NEW heads. The case work. Rotating assembly balance. Headers. A trans to handle the power. New CVs to handle the power. New flywheel and clutch package. It adds up quickly.

Posted by: mepstein Dec 2 2021, 09:23 AM

In the 911 world, it’s very common that owners with new engines over rev them, bend valves and then want the engine warrantied. Huge headache for everyone involved.

Posted by: Mark Henry Dec 2 2021, 09:45 AM

Years ago I had a kit 356 customer who wanted a kick ass engine, I built him a 2.7 nickies engine at least 180hp. I had it perfect sorted, quite the blast in a 1600-1700lbs car.

First he wasn't happy with the power, he implied he was expecting LS3 level power, even though I clearly told him a T4 will never have the power of a modern engine. I had also offered different engines like a subi, etc before the build.

Then even though he was told not to rev beyond 6500rpm he reved it so high he drove one valve guide into the port, fuched the head. He argued up and down that he did nothing wrong and then that a balanced engine should be able to go to 8K. In the end I wouldn't cover it, but I did repair it and as expected he was not a happy customer.

Posted by: 930cabman Dec 2 2021, 10:40 AM

Not every customer is a good customer.

I always interview a potential customer and often tell them "we are too busy" or just don't call them back. I have been known to fire customers because they are too much of a PITA

Posted by: NARP74 Dec 2 2021, 12:06 PM

If you need some high altitude testing, +6000 ft, let me know!

Posted by: NARP74 Dec 3 2021, 06:04 PM

Watched a TV show about Porsche bore score. They wound up going to this company in England for engine work. They are doing some cool tech on newer engines with liners and coatings for heat and wear issues. Might be worth checking out to see what they have.

https://hartech.org/

Cheers