Anyone using titanium engine parts??

[Doug S.]

I developed a healthy respect for the light weight and strength of titanium when I started riding mountain bikes. It seems to me that given those characteristics it would be a good material for certain engine parts, and so far I have heard about valves and wrist pins, but not much else.

I'd like to hear from those of you who have used titanium in your engines--durability, strength, cost factor, whatever you think was important.

I'm buying small parts now, but once my "friends" at the IRS send me my annual winnings next spring I buy the reciprocating assembly and valvetrain.

Thanks for whatever helpful suggestions you may have, guys. Y'all RULE!

Doug

 

[Lynn Larsen]

I am using Ti valve retainers just to help in keeping moving mass of the valve components down.

I have looked at other Ti parts and just couldn't justify the costs; although, if I had the money, I'd have a hard time saying no to some of the stuff.

Regards,
Lynn

 

[Sandy]

I have Ti valves on one motor going together, and the RCR motor has them on the intakes. Also the Retainers on all of the motors. Keith Craft also said that the wrist pins in the motor were Ti but not 100% on that.

Ti rods as last check were at least double that of good billet one (Olivers, etc) I think you can even get them from some of the chinese manufacturers, I think a company called Facttop who looks like they OEM loads of con rods and other hi-perf parts had them. One issue with Ti is that it doesn't like to rub up against itself... I here the comments now ;-) and most have molybednum (sp) plasma sprayed on the sids of the big ends. Only seen a bent up one at one of the engine shops seemed light but had no frame of reference. Ford Performance in Anaheim has them also at Ty-Lites or some trade name like that.

Hmm, a 3" stroke motor with Ti rods... I had Better start taking some $$ from the kids college fund

Sandy

 

[Mesa]

We have used ti a lot in the race bikes. Of course the NSX has ti connecting rods but, that's not my fault. Had some custom ti rods made for one of my 1000's, they had some kind of design defect, sides of the big end wore out fast! Used ti valve retainers in many engines and currently the race bikes sport full ti exhaust systems. Gotta keep the weight down ya know?

 

[Jac Mac]

My use has been limited to Valve spring retainers etc.

I seem to remember reading that Ti has problems where lubrication is marginal or where it moves in relation to another component. The face of the retainer that contacts the valve spring can show quite high wear rates if there is movement between spring& retainer. This may explain the wear Mesa mentioned on the thrust faces of his con-rod's.

Jac Mac

 

[Doug S.]

All good info!!

That's good info, Jac. Do you think a high volume oil pump might eliminate the scuffing? I'd like to build this motor with lightweight parts so it revs freely, but of course durability is a critical issue, too. I don't want to have to pull the motor apart every 10K miles to do a rebuild, that's for sure.

I've wondered about con rods, Sandy. The thing I like about Ti for bike frames might be a bad thing for con rods or push rods--anything under pressure. Ti flexes and returns to shape very well, so in effect the entire bicycle frame becomes somewhat of a shock absorbing structure, but that very characteristic might cause a push rod to deflect significantly under the load of high pressure valve springs or a con rod to flex under the load when the spark plug fires. Ron Earp and I both have this fascination with short stroke motors, and I can envision a 302 block with a good forged 289 crank--even shorter than the 3" stroke of the 302 and lightweight, too. You're right--the kids may need to fend for themselves!!!

So far the best use seems to be in the valvetrain. Anyone else out there have any experience with Ti?

Thanks, guys!

Doug

 

[Mark Worthington]

Titanium galls easily and is highly notch sensitive - that's why you generally don't see it used in fasteners. However, it's great stuff for reducing reciprocating mass (e.g., Ti rods) and valvetrain inertia (e.g., valves and retainers) for a high-revving engine.

 

[Ron Earp]

, and I can envision a 302 block with a good forged 289 crank--even shorter than the 3" stroke of the 302 and lightweight, too.

Anyone know what the largest displacement / shortest stroke that anyone has built? Obviously burning both ends there, but I think you get my idea. Like, say, a Dart aluminum block at 4.125", and a short stroke, what would that get?

2.87" stroke, 4.125" bore, that'd make 308 inches wouldn't it? All forged, lightweight components, good sized heads and valves for upper RPM, and a solid roller cam that doesn't come in until about 3500 RPM. Woo weee!

Sorry to digress. No Ti for me except for retainers, and they seem to work there. Seems that Honda figured something out if they used Ti rods in the NSX, don't recall that motor having lots of issues or anything like that.

 

[Lynn Larsen]

Ron,

According to my motor math spreadsheet it would actually be 306.8383727.
So, probably more accurate to call it a 307, but 308 is close enough for government work.

But also keep in mind that the dart can go to 4.185" bore which would give you a 316 (315.8294978). If you checked the wall thickness with ultrasound, you might could go just a bit more. One of the big advantages of the Dart block is the trueness of the cylinder bores which allows for the larger over bore.

Regards,
Lynn

 

[Rob]

Cube calculator

Hey Ron,
While on the cube calculator topic, I made a simple cube calculator in excel that I'd be happy to post for all to utilize, but don't know how I'd do so.
Rob

 

[Pete K.]

I believe the C6 Z06 also has titanium connecting rods.

 

[Jac Mac]

Ti Scuffing.

Doug ,I think Sandy probably hit the nail on the head, coating's etc that retain oil for surface lube probably being used by Honda etc. Since the total side clearance of the paired rods is approx 6/7 times the brg clearance any oil pressure disappears @ the edge of the brg shell.

I like the idea of building a super short stroke/ big bore combo, anyone know what the c to c length of the ZO6 rod is, you may be able to grind your 289 or shorter stroke crank to the ZO6 bearing size & use a short piston with this to get what you want for a lower $$$$. The Flat plane crank starts to look viable when you get down to this sort of stroke. With this combo the piston is going to be 'parked' @ TDC longer so deeper valve pockets will be required, which means it will be harder to acheive higher comp ratio's.

Whatever you choose, make your exhaust with an 8 into 1 collector, even the Porsche/Ferrari guys will shut down to listen to the music.

Jac Mac

 

[colin artus]

You can also find Ti used for valve springs (and suspension springs on the Porsche 917!). The aerospace industry use lots of Ti fastners - they are use only once.

 

[Keith]

Anyone know what the largest displacement / shortest stroke that anyone has built? Obviously burning both ends there, but I think you get my idea. Like, say, a Dart aluminum block at 4.125", and a short stroke, what would that get?

2.87" stroke, 4.125" bore, that'd make 308 inches wouldn't it? All forged, lightweight components, good sized heads and valves for upper RPM, and a solid roller cam that doesn't come in until about 3500 RPM. Woo weee!

Sorry to digress. No Ti for me except for retainers, and they seem to work there. Seems that Honda figured something out if they used Ti rods in the NSX, don't recall that motor having lots of issues or anything like that.

Transam pushrod motors are (were :shrug: ) 310 cubes; Bore: 4.056 in. - Stroke: 3.00 in. giving 650 hp @ 8,200 rpm and boy, did they sound goood...(even without Xover exhaust)

 

Anyone know what the largest displacement / shortest stroke that anyone has built? Obviously burning both ends there, but I think you get my idea. Like, say, a Dart aluminum block at 4.125", and a short stroke, what would that get?

2.87" stroke, 4.125" bore, that'd make 308 inches wouldn't it? All forged, lightweight components, good sized heads and valves for upper RPM, and a solid roller cam that doesn't come in until about 3500 RPM. Woo weee!

Sorry to digress. No Ti for me except for retainers, and they seem to work there. Seems that Honda figured something out if they used Ti rods in the NSX, don't recall that motor having lots of issues or anything like that.

Kuntz&Cie built for me a 2.87x4.125 dart aluminium block with Pro tpo line Iron heads, made 473@6500 and 410 lbs torque,also have built for a friend a 2.87x4.00 with tit rods and whrist pins,early GT40 heads with tit valves and retainers.

 

[Doug S.]

Found on eBay

Just in case anyone reading this thread is curious about prices for Ti pieces, read on.....

http://cgi.ebay.com/ebaymotors/LS7-...006QQitemZ160028324462QQrdZ1QQsspagenameZWDVW

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[edited to include description and price] In case you are reading this after the auction closed, the Buy it now price for these LS7 parts was $2300 and here's the description:

This auction is for one set of 8 Brand New Titanium rods

These rods weight in at an amazing 465 grams and have the strength of a 900 gram steel rod.

This is one of the best and strongest racing rod ever built
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Well, they are for a Chebbie, but these came up when I did a Google search. Pretty expensive for a GM part number.

OUCH! I sure hope they are less expensive for a SBF, but I wouldn't count on it.

 

[Sandy]

I think I have seen the SBF's HBeams starting in the $2500 range, but that was a while ago when I first had Ford Performance do a motor. He had a bent up rod that had a top oil issue and the pin siezed as I recall. I think he said he was running a vacuum pump and had very little oil in the pin area.

As for GM running the Ti rods, seems like a marketing thing, I ran 7200rpm with 3/8" bolt forged chevy rods in a big block for a long time and never had a problem (I was lucky I think). Don't know much about the Vet motor, but it does make a good amount of power and is easily driven, but does it really need the Ti rods?

I keep thinking of the Nascar folks running well into the 9k mark with a nice steel rod.

And someone else might be able to answer this, but for the same given size of steel is Titanium as strong? For example if 2 rods were the same exact sizes would the Ti rod be stronger or the Steel? I'm guessing the steel will be stronger but heavier, but don't know for sure.

Sandy

 

[CliffBeer]

Wonderful metal. Ti is difficult to machine unfortunately, so, be sure the Ti parts you order are an exact fit for your car.

I've seen Ti used as connecting rods and also CV axles. Ti s generally not used for cranks partially because of the intensity of machining necessary for a crank and also the sheer size of the billet from which the crank must come (either forged/cast or 100% machined) is quite large and therefore extremely expensive. Ti is great for CV axles as it reduces unsprung weight and can take a beating. Many race cars use Ti drive axles.

Ti is also quite resistent to oxidation/corrosion. It doesn't spontaneously blow up like magnesium when put in contact with certain other common elements.

 

[Sandy]

Cliff -

Is it's strength for the same volume as strong as a steel (4130 or better)?

Sandy

 

[CliffBeer]

Cliff -

Is it's strength for the same volume as strong as a steel (4130 or better)?

Sandy

Sandy,

By volume it is generally materially stronger. There are several flavors of titanium but all are stronger by volume and, obviously, dramatically stronger by weight. Interestingly, titanium is pretty malleable and quite resistent to shattering unlike some of the really hard steel out there.