The asking price is $2500.....to dear for used rods me for I think since they would still need new bolts, bushes and big ends checked/reworked. The stock rods I have are marked "S", so 584-588 grams. Carrillo steel rods would be 504 grams, much better but not the 400 grams the Ti rods are. The pauter steel rods confuse me a bit since they list the TR and 308 rods as different lengths and pin sizes as well as 504 and 585 grams respectively but I'm guessing that the 308 rods they've made were for a boost engine and made heavy to handle it. I need to think some more.
I have used both Pauter and Carillo rods in road racing engines. The Pauter rods came in an engine in a car I bought. They were nicely made, and did ok up to 7500 rpm without a breakdown, but I always had it in the back of my mind wondering if they would hold. Have used Carillo rods to 12,000 rpm for many hours up and down with sometimes sudden rpm changes with never a failure and they always crack checked clean. Consequently the only ones I will buy and install are Carillo, and I never worry about them. The folks at Carillo are very nice to work with and will build whatever you want. It sometimes takes several months before they are delivered because they do their heat treating and such in batches, but are well worth the wait. Hope this helps... Scott B
Scott, It does help some. I have 2 concerns. The first is if the rods will stay together and the second id how much extra load and flex am I inducing in the block and crank. I weighed one of the original rods and got 588.5. the piston/pin is 440.2 and the bearing 35.5 (I didnt clean anything first, so that would save a little weight) giving a total of 1064.2 grams. The carb version redline was 7700 with all the same parts, so Ill use that as my known safe point. I had in my head building for peak hp around 8500 and set the redline at 9000. The stock cast pistons are pretty thin so I dont think Ill save a lot weight there, the new wrist pistons will be lighter Im sure, but Ill just assume stock weight piston/pin/bearing for now. Then going to 9000 with stock parts increases the load by 37%. The 504 g carrillo rods drops that to 26% and the 400g Ti rod to 12% (at the 355/360 redline of 8500 the number is 0% .I doubt thats an accident). At 9500 the numbers are 52%/40%/25%. The lighter rods reduce the loads significantly. Im guessing the OEM redline is more about rod bearing life than failure concerns and there is a significant safety factor built in. The fact that James says theyve run stock rods to 9000 confirms that I think .but Ive weakened the block somewhat by welding and overboring it. I get additional stiffness in the block because its bolted to the trans which is strength than the OEM pan I guess so maybe its a wash on strength. It looks like the Ti rods give a significantly larger safety margin on the crank and block but I dont know about the rods themselves not knowing the exact strength of each of the options. I do know that Ti is strong, but its less stiff then steel. I also just learned that Ferrari specs a little more clearance in the bearings when the Ti rods are used and yet I know of 3 355 engines that spun rod bearings making me wonder if big end rod flex isnt perhaps the underlying cause. Now you see why Im so confused
The asking price for the 12 I found was $2500....which is more than the price of top shelf steel rods that would give me 1/2-2/3 the weight savings with none of the other questions Id have about used Ti rods like coating integrity (the sides of the big end gall if not coated) thread fatigue, corrosion, ect. Im thinking that if I can get them for more like $1500 Im willing to spend some time and money on them to put my mind at easy about them but over that Ill just get a good set of new steel rods.
Mark I think you should be able to get a good set for under that .I said to you I missed a set of 8 that went for 205 pounds $410 so they are out there , patience
I sleep like a kid on christmas eve with thoughts of this engine simulation dancing in my head Now that I have to buy cams anyway, I'd hate to not get good ones..... If a honda s2000 sounds good at 9000, a 12 cyl at 9k should sound 3 times as good.... hmmm how esle can I rationalize this foolishness to myself........ Image Unavailable, Please Login
Yeah, but the problem always is that to keep a project moving decisions need to be made and action taken. If I plan on Ti rods and used ones dont turn up then Im stuck buying new for $4k-$6k. I think $50 a piece 360 rods was more a fluke than the norm and I really don't think I can plan on finding more at that price.
By the looks of that graph you will greatly surpass your goal of 600 HP N/A by a wide margin. And a V-12 at 6000 sounds much more like a full orchestra while the Honda at 9000 just sounds like one good violin. You could put a 7700-8000 rpm rev limiter on the engine, and live long enough to die knowing nobody outdid you. One of the most awesome machines I ever imagined was the Koenig turbo compound TR. Twenty five years later that car could still spin peoples heads, and nothing in all these years has really surpassed it in brashness. Yet you are on the edge of blowing it away in spades. It dont need to turn 9000, Mark, you'll have already struck gold just making it move under its own power.
The original goal was 51 pages ago.... You're right that goal creep is a problem here. I originally planned to use the stock TR cams and match everything to them as best I could and thought 550-600 at about 7200-7500 rpm is were the engine would come out.....but then I realized the cams won't work and I need to make billet cams. I certainly could make new cams to the original profile but that just seems like such a waste of billet cam blanks. I know lifts in the .425 range are possible and will help so thats probably the direction Ill go since its much easier to grind some off if Im not happy then it is to more on if Im not happy. Then I think what I can do with the heads is what will drive the whole engine. I need about 150 cfm (at 10 h2o) to feed this thing to 8500-9000 and thats a lot of air for a head that starts down around 100 cfm. Less air means the engine will peak at a lower rpm and continuing to spin it would be a waste. Im thinking Ill build a solid bottom end that can handle whatever the top end can deliver.
One more head gasket option was suggested to me yesterday. I could take a TR head gasket and just cut the flame-ring sections out and use it to seal the oil and water. Then fit a copper flame-ring to the liner to seal the combustion chamber. Something else to think about....just what I needed
Just to make sure a good nights sleep is not in your future plans... I called and checked on the flame rings. The ones I was thinking about are for a 86mm application and I remember they had a good 1mm o/s ID when put on the liner tops. $9-10ea. Another alternative is for the 88mm bore and they are in the $5ea range. Both are near .050" thick. Some brass, some copper. Just measured a compressed Daytona headgasket and got .051" at the flame ring.... Dave
Dave, Do you recall how wide they were? I have an 86.5mm ID and the flats are at 98.8mm on the outside leaving a max width of 6.15mm
Realizing you are very busy, thank you for the follow up on the rod issue. Having woked on the Porsche 917 engines I found the titanium rods to be fairly short lived. Even the newer P engine with Ti rods are not so good....and the cost can be prohibitive by the time they are coated. Also all the calculations for the forged steel rods are very well known from all aspects of temperature and stresses. Additionally would recommend spending a bit extra for the forged pistons. It will help with your weight issue and they will tolerate variations in stress without coming apart. And finally, o-rings for what you are building, is essentially a race engine has been proven over the years to be the best solution. And, if you are thinking in the future of increased compression through turbo/supercharging the engine, the o rings will make it that much less complicated... Scott
I had a dumb*ss moment last night and tried to put one of the cylinders in the wrong place by 4mm ..so I had to pull the block off the mill and weld it back in tonight. Even so Im almost done with the first side now. I just need to make the finish cut down in the bottom and clean up around the studs so water will fit. I think Im going to leave the o-ring pocket and the finish depth on the flange until after the finish decking. Image Unavailable, Please Login Image Unavailable, Please Login
I forgot I had made a jig to surface plate the rings to match all the installed liner heights on the engine I did. Measuring the jig they look to be 86.4mm ID and around 95mm OD giving around 4.3mm wide. Sounds to me the 88mm (read, Cheap ones) might be a wonderful match as I think the OD remains the same giving 3.5 wide range Dave
Comments and suggestions are always welcome and appreciated, it makes for a better project in the end. I think you're probably right on the Ti rods. If I can get them at the $1500 price I'm willing to give them a go (I already made him an offer). If that falls through it will be carrillo's. The pistons will be forged, probably wiseco. I don't have a choice about getting custom pistons since the bore is custom and the heads are 4v on a 2v block. The compression ratio will be around 10.5:1 The head gasketing has been an on-going what to do. The liners will be cut for some type of o-ring but sealing the rest is an issue. I' torn between a copper head gasket with a SS wire in the liners or a stock type gasket cut out to accept the o-ring on the larger bore. O-ring everything (water and oil) is possible but a real pain due to the shape and length the one long o-ring for the water would end up. Last, supercharging/turbocharging is a running joke on this thread since my old engine was supercharged.....but this one will be naturally aspirated now and always
I goofed up my numbers some how... I know the bore spacing is 94mm, so the OD can't be larger than that.....I don't know where I got 98.8. It sounds like I'm out of luck. I could just make rings (for free ) and still use your gasket idea.
Easy deal with a parting toll and a length of what?, 642? Way too much work if going that direction compared to filing a .7mm flat on 2 sides to Siamese one to the next. For $60 I am not so sure you could buy the brass. It is at minimum another alternative thought and I will try today to find some photos of the assembly job where I used these type of flame rings. At 890HP, 10,200 @ 10.5/1 (might as well move the bar up a little, remember "excess is barely adequate" and there will be more creep before you are done) you are going to need some serious sealing capibility what ever you use. Over built in that area will be good when you no longer can resist the temptation to hang a hair dryer of some sort on the engine. Dave
Oh...I had it in my head they went into a groove in the liner and flats wouldn't be allowed. Flats would be very easy. To get 890HP I'll need the supercharger Spasso is waiting for..........or nitrous
Or spin it faster disclaimer.....I don't think anything I had to put into the computer to get this graph out was the truth. Image Unavailable, Please Login
