What are the advantages of H-Beam rods over stock rods in a 2.0L motor? I know the H-Beams are lighter and stronger but in terms of performance what are the advantages of using the lighter rods?

Lighter rods would mean less rotating mass. Probably negligible improvement on a street motor.

I wouldn't bother unless a race motor.

Thank you two for your responses! I am surprised there were no pro H-Beam responses from anyone. I remember reading that Jake uses them in all of his engine builds so I figured there would be some responses in favor of using them. I'm still on the fence about whether or not to use H-Beams or get my stock rods reconditioned.

You need to keep in mind what kind of motors Jake builds, not your typical rebuild by any stretch of the imagination.

Street motor, or even slightly hopped up, I would not waste the money on h beam rods.
I would replace the rod bolts.
I would get the old ones trued up and balanced.

I would focus all my spending on the heads, camshaft, and push rods.
Get the heads ported, get them down by a pro with a flow bench.
You will not regret balancing the heads for performance....even on a stock motor.

Rich

They are better by being lighter and stronger. Depends on what your after.
I had a race 2.0 with lightened stock rods and 130-135 hp. It wasn't cost effective to use H-beam rods in hat one. But to go to 8,000 rpm I would.

Depends on the application

This is primarily for a street car. Maybe some auto x but 95% for the street. I have a set of KS flat top 94's but may bump it up to 96's for a 2056. I'm thinking of using a Webcam 494 cam and around 9:0 to 1.0 compression. I'll be running a pair of Dellorto 40's & SSI heat exchangers.

Used the H-beam rods in mine, 2056 with 96mm KB flat tops.

Raby 9590 cam, Ham heads. D-jet

Probably overkill for a street motor.

Can't say how they run, cause body work is still going on. Engine and trans are ready though.


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That cam won't make power over 6000rpm, H-beams are a waste of money.

Hi Mark! Thank you for your replies. From all your posts I've seen on here I can see you have a lot of experience and knowledge about Type 4 engines. I would like to squeeze the most performance I can out of this car while maintaining reliability and good street drive ability. I'd also like to keep heat in the car and I have a virtually new set of SSI 2.0 heat exchangers. I also have a pair of completely refurbished Dellorto 40 carbs. I have a couple pairs of 2.0 heads in great shape. What cam choice would you suggest that may be better? I live in the SF Bay Area so I'm basically at sea level. Any input will be appreciated. I have most of the parts needed and am not interested in a Raby cam kit for this motor. The Raby kits seem to be the Go To solution for many on here but I wish to have an alternate solution. I'm sure his stuff must be awesome but I want something different. Elgin or EMW cams are another option.

Nothing? I think this thread is dead in its' tracks!

Sadly the discussion of modified Type IV's is going to be less and less it seems as those that are in the know move on to something else

Thanks for the reply Mueller! Sometimes it's like trying to find hens teeth to get information. Unless one is upgrading to a motor from a 911, Subie or some V8.

How's your new 914 coming along? I read on here that you finally found another one. I met you at a 914 breakfast get together a couple months ago out in Pleasant Hill. I think you were driving a Range Rover as I recall. I'm surprised Jake did not pipe in since his name was mentioned.

Have you priced H beam rods recently? by the time you resize and rebush your own rods you're not that far off. I installed them on my 2056 and have been very happy. I am also using 96 KB pistons and a Webcam 86A. I'm pretty happy with the performance and will be adding a header system this spring. Also running Dell 40's
Joe

When you go to a stroked crank you must go to a CNC rod because the stock rod will hit the case. The CNC rod has a smaller big end.

Hi Joe!

Thanks for your input! I've considered a Webcam 86A. When does the power start coming on with that cam? Is it good for street driving? Does your car idle smoothly? I thought the 86a was better suited in the higher RPM range but I may be wrong about that. I believe that's the cam RacerChris uses in his racer which leads me to think it's best at high RPM's.

Yep agree, I've been building engines for over 25 years, I used to give lots advice, I got tired of being told I don't know shit from armchair engineers that read something on the internet.
I don't give much advice anymore.

I've had an 86a in my 2056 for years. It's street friendly and begins to make power in the 3-3500 range. I've been satisfied with it. I'm going more aggressive with my current build.


80mm crank and rods.

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Cool! Are your rods 5.325" or 5.4"? What cam are you using and are you sticking with 96mm P&C's?

The rods are 5.325. Cam is an 86b/86c on 105 degree lobe centers with a reduced base circle. Pistons are 98mm JEs with raised pins and biral cylinders.

I've seen those Biral cylinders on a couple of sites. Do you have any experience with them? I've not seen anyone that has used them on a 914. In theory that sound like a great option to me but some folks have said they don't stay round because the iron sleeves are too thin. Not that they've actually used them. I believe they came from the factory on some 356's and early 911's. I doubt Porsche would have used them if they were problematic and probably switched to iron to cut cost.

They switched to nikasil and alusil, in the 911 the birail cylinder was a transition part as the HP increased. I think staying round isn't the issue as much as separation of the two materials.

I have never used them before and haven't heard of anyone else using them either. That being said this is a race motor that will be getting yearly tear downs.

Good luck with the motor and your race season! Please keep us informed of your experience with those Biral Cylinders. I'm sure there are other people curious about those Birals! When will you have it up and running? What type racing will you be doing?

It's an autocross car but will see some track days. Hopefully it will be in and running by the end of March.

Actually, I removed that cam from my "B" engine last time I had it apart, and installed something slightly more aggressive.

I used the 86a for several seasons with great success.
Its very street friendly when coupled with stock heads & low compression.
However, the cam likes compression.
I pulled about 140 hp from a 1.8L by porting the heads and bumping the compression up to 10:1.
Those changes moved the power band up to 4000-6500 rpm - which required installation of better rods.

Better rods for the 1.8 are available? What about the 1.7's?

I can only seem to find them for the 2.0 motors.

I totally understand Mark! There are a few opinionated people on here! That's true in any forum. Most are very cool and helpful!

Hey Woody! Looks like you're off to a good start with your motor. How much is that flywheel lightened? Also what do you have mounted on the top end of your crankshaft?

I'm going with an upright fan conversion from Fat Performance so that is the belt pulley. The clutch and flywheel weight 14 pounds together, I think the flywheel is around 8 or 9 pounds. It's from Patrick Motorsports. I'm not convinced that the Fat kit was the best money spent when there are other options out there that would probably work better. I bought it years ago and decided to give it a try. Chris at Tangerine has a flat fan setup that I wouldn't mind giving a try, maybe next year when I recover from how much I've already got in this build. Jake also has his DTM setup that directs the airflow to each cylinder and head that may be the best option out there but I'm not a big fan of the aesthetics of it. My goal for this engine is a very light rotating assembly as there is a bunch of accelerating and decelerating in autocross. This will change the whole nature of the car. Here's a pic of the clutch and flywheel setup.

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The FAT kit is no worse than any other 911 fan kit, I just hate them because in a T4 into VW bug conversion they fit like shit. They sit too high.

I'm waiting for the 911/908 based horizontal fan for the Type IV...

I wonder how much HP that gear box for the fan sucks up!

I doubt it is noticed much on the motor below...claimed 900hp + !

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The worst ones are the guys who know enough to be dangerous. They have done a few things a bunch of times, and many things a few times, and know the theory, so they can sound really authoritative. But then you find out that their car hasn't run right in years...

Uh wait, where was I going with that??



BTW, I recall reading that the gear-driven flat-fan setup in the 935 sucked up something on the order of 30 HP at redline. Not a big deal if it helped your 700 HP motor live through a 24 hour race, but kind of a big deal to those of us with 100-200 HP motors.

--DD

Not the same as the Porsche solution, but Chris (Tangerine) has a horizontal fan set up for the T4.

Mine are Carillo.

Lowest hp draw Type 4 fan cooling system.
Retains the stock alternator, driven at a lower rpm than stock.

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That couldn't be further from the reality of things..

Its possible to know more than one thing passionately. Hell, some parts from watercooled Porsches are being adapted to the T4, including variable valve timing components :-)

I love the look of this system. It's pretty badass like most everything Chris makes!

Woody,
I love 5.325" rods with an 80 crank, it'll snatch your head off. I've been using them since around 1995 :-)

Thanks Jake I appreciate the input. I sure had an adventure making the rods clear the cam. The cam is on a reduced base circle and the rods are 2" on the big end. I don't see how you could go much bigger on the stroke. Now to get the rods balanced again. The nice thing is the deck height is right at .005 without shims. I'm going to run it at .040.

The magic number for a reduced BC on a T4 cam with up to .390" lobe lift is 1.045"

I can make the rods clear with 1 gram removed from each corner as long as they use 5/16" bolts instead of 3/8".

This combo will drop in, generally.

I went with the 3/8" rod bolts. Kicking myself now but I got them to fit. Just had to take off more than I wanted. I would like to be able to twist this thing to a safe 7,000 rpm and I was leery of using the smaller rod bolts with a 98mm piston. I'm sure they would have handled it in stride.

The issue is all the material removal makes for a weaker rod than one that has a 5/16 bolt with less clearancing... Guess how I know.

The smaller bolt is no problem if you use an ARP 2000 custom aged bolt, or a SPS- CARR bolt.

I have one engine with 5/16 bolts that puts down 595 RWHP at 35 PSI boost. The rod bolts are changed once per year. It's all in the combo!

That's certainly what it's look like. I am using ARP 2000 bolts. 595 hp is very impressive. Yearly teardowns are part of the plan. It's not too late to go with 5/16" rods. Maybe I'll do that for more piece of mind.

I think I would. I've ripped the threads out of a rod cap in the past when doing it the way you are now.

it looks like there's plenty of thread engagement but I had to take off more than I am comfortable with. I'll try the 5/16 rods and report back. I've got enough money in this one to not take any chances. Thanks Jake.