Just wondering what most of you are running for a bottom end on a TT setup. Making sure after i get this motor built that as soon as i boost on it nothing will go wrong and that it wil at least last a couple of months. Wont be driven that hard every weekend. Mostly 2 track days a month. ( of course tuned right). Oh BTW this will be on a 6.0 iron block.
Thanks for the input.
Mike

 

You goin boost too!?!??!

Come over to LS1tech to be all quiet!

 

Haha. i got the 6.0 block and a friend of my from a company in berkely designed a TT kit... so shhh. been doing this for about a month since i couldnt sell the car. Going to be going w/ the 409 kit i belive and im looking for what brand weight/strength.

 

Anyone?

 

stock crank, forged rods and pistons. lots of options to choose from

 

i understand that i need to go forged and all of the components that i will need. Im just looking for what brand bassically.

 

I run a low comp HPE built 408 with forged internals (of course), i need to lower the comp more to get closer to 8:1

 

I run a Callies Crank $1300ish, Eagle Rods $450ish, and Coated Diamong Pistons $550ish plus coating....409 Iron.

 

I don't think you should be looking for advice on exact specs here as it all depends on your goals and the size of your wallet. I suggest calling any of the sponsors to see what they would build you and how much they would sell the parts for.

Personally, i think you should call HPE as they are building me a 398 iron block capable of 1500 hp with forged everything. They are very knowledgable and are usually willing to spend as much time as it takes to discuss your needs. I just sent them my 6.0 ltre heads so they can have them ported and set me up with some nice valves. Sadly, I do not know anything about engine building so i am leaving everything up to them as they have a 8.35sec 168mph LT-1 that is looking to be in the 7's here shortly. Yeah, i think they know what they're doing


Greg

 

Haha thanks alot. ill give them a call tomorrow.

 

Forget stroking the crank. Stock stroke is best for boost. You can even use the stock 6.0 crank. Done it many times already. You dont need cubes for boost.


Rick

 

What?????
I agree that stroking is not "necessary" to create power in a FI application, but it is definitely desirable, as you will create greater cylinder pressure per a given boost or flow level with a stroker than with a stock stroke motor FI or N/A. I am not an expert in engine building or forced induction theory, but I think you need to explain why the stock stroke is best. Are you referring to a turbo application only, a supercharger only, or either? Not trying to flame you, I just want to understand. I think since most of the responses on this thread are either already using strokers or are going to them, we need an explanation.

Thanks,
Tom

 

From the motors I have done and the FI stuff I have seen and done as well, I found that shorter stroke makes more power effectivly. Sure you make more NET power with more cubes, but if you compare apples to apples, the smaller motor will make more power for what its worth.

Look at it this way. What happening in a stroker motor, there is more piston speed. So from this you could look at it and say great, faster cylinder fill. But I look at a slower piston speed from a non stroker motor as a better way to effectivly fill the cylinder at the same RPM. Basicly allowing more air to fill with the slower piston at certain points of the RPM. Now another benifit I look at is less heat created with a non stroked motor. When the piston travels faster in the same amount of time, the rings generate more heat. With an all bore motor, you can disapate the heat better because the rings are bigger now and there is more area to lose the heat.

The other great thing I like is less wear and tear on bearings and crank with non stroked motors. With the rod being longer, you put less wear on the bearings, less piston side wall forces, the pistons will have less drag also.

So in my eyes there are alot of things that are important to me to make the engine last. If I want to make the TQ sooner, that I could stroke it. But thats all a stroker will do. Put two motors side by side with identical cubes, one a 383 stroker, the other a 383 all bore. The only difference in these motors is where the TQ comes on. I think I am doing pretty well with some cars being that one is a 370CI motor, stock crank, on 13 psi making just under 700RWHP on 91 octane. Also, alot of the other big players on this board are all running less cubes, almost always under 400CI. And they are making big power. I say let the boost do the work, not the motor. I hope this helps. And if you have some good facts to add, please feel free. I love to learn new approaches to engine building.

Rick

 

I would agree with Rick, despite the fact I have a 409. That was an "early" decision.

 

I have to disagree too. Most of the top boosted motors are using stroker cranks.
there just isnt any replacement for displacement. the more cubes the better. you dont have to spin the motor as high to reach the effiency range of the turbo, which will make the motor last longer.

 

Sorry, I still don't see it. I agree that a long stroke will make more torque at a lower rpm than a short stroke, but it will also make more HP on the top; it will make more avg power across the entire rpm band, where with a short stroke, to make the same power, it must be on the top end.....this will definitely wear the motor out faster. As to the heat issues, the aluminum blocks and heads dissipate the heat quite adequately (a 160 thermostat doesn't hurt either). I don't understand why so many guys are using the iron blocks. The engineers I talked to told me the aluminum blocks (especially the LS6) will take 1000 hp no problem and that any reported failures were due to other components failing, not the blocks. Anyway, I plan to auto-x as well as drag race, and maybe even a little roadracing. My stroked/supercharged application (LS6 block w/160 t-stat) will make decent power from 2000 'til she blows with a strong upper mid-range (3500-6000) without being peaky (broad, flat torque curve). I plan to be all done by 6800 w/rev limiter at 7000. My cam is good for 1300-6300 w/stock rockers, I have 1.8s so it will be more like 1500-6500. It is a small cam, compared to some of the monsters some guys are running, but I believe (confirmed by Brian at TEA) it is matched to the heads very well and will give me the low end torque I want with the s/c making up any limitations on the top end. The s/c is pulleyed to make boost from just over 2000 'til she blows; 7000 rpm will not be a problem if I want to rev it that high. In fact, my machinist told me the bottom end is good to 1250-1300 hp and will take 8500 if I want to go that high. I expect it to make 650-700 rwhp without taxing any of the components to their limitations. The motors you are talking about making 700rwhp are making it from 3500 up. While this is ok for a car setup stricly for drag racing, it is not good for much else. My car lives 98% of the time on the street (and in the garage) and will see limited strip time, but when I am there, I expect to run mid-low 10s at about 137 mph, if I can get it to hook up. Then, I can leave and drive to the auto-x track, hang with the best of them, then take a cruise out to the Texas hill country and enjoy the way the car handles in the hills and twisties (to me this is the most fun). Will I have the fastest car at the strip, probably not, but if you can beat me at the strip, you probably won't be able to keep up on the street.
Sorry so long, caffiene does that to me early in the morning.

Tom

 

Its all good, I like other opinons.

But I view it this way. You can have all the TQ on the bottom you want, but when I ride along in one of our cars, we can even keep traction at 3500RPM. So why would I want to have it all under 3k to start monster TQ at 2k? You also said I would have to spin the crap out of our setups, but looks like you are spinning alot higher than we are with out setups. So I still dont see the advantage yet. More RPM's, more wear. Big arm motors like strokers will always put more wear on bearings. Plus you have to forged the crank to have a stroker motor if you want it to last. Some people would like to use that 2 grand of a crank and put it into the heads where it realy counts. OR the cam as well.

I do agree that with a stroker you will have more TQ aross the board yes, but realy, how do you expect to use all that TQ down low when you race someone on the street? Thats why most people go turbo, works out great for us. By the time we are rolling we have almost all the traction to go. But I would like to see your Dyno sheet when you are done so I can see where yours comes on and drops off. Any time frame when its done?

Rick

 

Yeah, I have been waiting 2 1/2 years to see if my specs for this motor are accurate.

Sorry, I did not mean to imply that I would be making most of my power down that low, though the cam and stroke will likely give me good torque from just off idle. I just hope to get the boost to come in somewhere between 2200-2500 for some serious grunt coming out of corners. I would expect in the neighborhood of about 400+ lb/ft when boost comes on and progress (due to the linearity of the s/c) to a peak of over 700 (guessing) at about 5300-5500. Peak power (650-700rwhp, if I hit my target) will probably come in about 6300-6500 and still be making 575-600 at 7000. But this is all academic until, as you say, I get it on the dyno.

I also did not mean to imply that you have to wind the crap out of your cars to make power, just that a smaller stroke motor must rely more on higher rpms to make the same power as a stroker motor, whether FI or N/A. To make bigger power, they become peaky, especially with a turbo which has a more explosive power curve rather than the more progressive power of a s/c.

My intent when I spec'd out my motor was to have a car that excels at many things without being tied to a particular kind of racing. Sort of a jack of all trades, master of none. While I enjoy straight line racing (at the track or elsewhere) it is very hard on a car and, as I stated above, I also want to auto-x, maybe roadrace a little, and cruise the countryside with a lot of low end torque to plaster a big smile on my face. For an all-around great performer, a stroker motor is better, IMO.

When I get the motor installed and tuned, I will be glad to post some preliminary numbers to see if I am in the ballpark with my specs. Once it is broken in good, I will post the updated numbers and see what she will do at the track. In the mean time, while I am breaking it in, it should be loads of fun in the hills.

Sorry, RumblingZ28, I didn't mean to hijack your thread, but I wanted to understand why a short stroke motor is better for FI than a longer stroke. Not too sure I got my answer, but it seems to me that if short is better, then de-stroking might be a good thing. Don't know. Might work on a turbo application, but I still think for a s/c application, a longer stroke is the way to go.

Anyway to address your question, it depends on what your power goals are. You can't go wrong with any of the name brands: Callies, Lunati for the crank (I personally don't care for Eagle products, I don't believe they are up to the same standards as the others), Diamond, Lunati, JE, Ross, all make good pistons, and Carrillo, Oliver, Manley, Lunati, Crower for the rods (seems most guys are going with H-beam rods, but if you look at the rods big names like NASCAR, etc. are using, it is the billet I-beams....Oliver, Carrillo, Lunati). Decide what you want to do, then shop around for the best prices. I personally went with all Lunati pieces because the quality is excellent, they are engineered to work together, and the bang for the buck was there, especially the rods...Carrillo and Oliver are very good but way expensive. Also, I did not go with a FI specific piston because they were mostly unavailable or extremely expensive at the time, but before I bought I asked some engine builders and they assured me the 8cc dish Lunatis would hold up to the 12-15 psi I will run. You may need to go with the FI specific pistons. Rick@Synergy can probably answer that better than most of us since he builds turbo motors.

Anyway, good luck to you in your quest for "Boost Nirvana" and I hope you have deep pockets, you're going to need them.

Tom