Ok, I am looking for some suggestions. I assume everyone knows the motor I am putting back together, or refreshening..............408ci, Roush/Yates heads (old cup heads) 15:1 pistons, cam is Crower #E-20104/00117R, fairly radical, Intake lift is .704, duration 307 Exhaust lift is .704, duration is 311 Lobe seperation is 108 Anyway, I just got a brand new Holley 8896-1 1050cfm carb for under $300.................My old carb was a Holley 850 that was mod'd by The Carb Shop and was flow'd at just over 1000cfm sitting on top of my Super Victor Jr. The car ran a 9.801 last year with the tired motor and trans with this carb/intake combo. So..................my question is, I will probably never go over 7000rpm with this old motor...............so what intake could I use to maintain or even go deeper into the 9's using this new 8896-1 carb. Thanks for your suggestions.
The car or motor was never on a dyno since I've had it. When the motor is refreshened I will put the car on a chassis dyno to break in the motor and trans.........then do some pulls to see where we are at tune wise. Since the car with me in it weighs 3325, the math says it was putting down around 600hp to the rear wheels..............I will put the motor back together with the old carb and intake before trying anything different. The motor was in fairly good shape when I tore it down (considering it had been together since 1998/1999) and although I dodged some really big bullets...........I don't really expect the performance to be much different..................we will see.
600 HP give or take isn't too shabby!! How about the heads. Are they ported? Are they big port? Small port? Restrictor plate heads or? I know (generally speaking) they're capable of 800-900 HP on a full-tilt engine but there were so many variations of the Yates/Roush heads that it's almost impossible to count them. The Dominator will likely pick it up a little. If nothing else, the larger throttle plates help responsiveness, which helps get it out of the hole a little better. And the Dominators do an excellent job of metering fuel...IMO, better than most 4150's do assuming there's enough motor to make use of it (and in your case I'd liek to think there is). Have you ever thought about Methanol fuel? Probably pick that car up a bunch. I'd guess .3-.4 easy. Maybe more. Mine was right at half second (.5) and consistency improved drastically though my old gas carb was, IMO, sub par for that particular engine. Perhaps the camshaft is out of range for your application? I am no cam expert. I leave that to those who get paid for their expertise. Keith Craft is "in the know" with Yates style engines. Might be worth a phone call. Ed might even be familiar with that setup. Used to have a set of Yates heads..wished I'd have kept them (sold them at auction...same auction I bought them at, same night actually) but the past is the past and I can't change it. Always thought that with the right Yates head setup I could make enough to knock the mains out of the block. Wait...havent I done that already with inline valve heads? One thing I missed is that the goal seems to be to stay under 7000 RPM. Good thinking-helps the block stay alive. However, making more power while keeping that RPM ceiling is probably going to limit the gains. The Yates stuff LOVES RPM and it's been my (limited) experience that they're happier at 7500+ than 5000-7000 range. Methanol would solve the RPM. Woudl still be at or below 7000 yet still pick up a bunch of power and more importantly torque. But I do not know the application-if there's any street driving, Meth would probably not be a good idea. Then again, all those random thoughts may be out the window....when it's dyno'd, ya might find something that is holding it back. quick question...How much total lead (timing) do you run?
Well, the heads are "Old" heads, sometime around the late 90's. They are TF R Twisted Wedge heads although there is no Trick Flow numbers anywhere, but there are serial numbers which I traced back to Roush/Yates. Yes, they are/were ported/polished, the exhaust side is kind of a D shape...........a little strange but...........the intakes are about the size of Cleveland 4brl heads and the Super Victor Jr. matches. I just had the heads gone through and found out that when Roush/Yates sold them they were bare. The guy that purchased them just put non-tool steel keepers and regular steel retainers. I also had to replace all of the exhaust valves as they were pitted so badly on the underside I didn't want to use them again. Also replaced the springs since the old ones were down almost 30lbs and I hate shimming springs. The heads are good to go after being refreshed. I attached pictures of the heads when I pulled them off, in one of my other posts I must have put the pictures of the finished heads because I can't bring them up as a picture again. The guy that had this motor built by CHP originally did run Alcohol, and then changed to gas..........hence the reason it is setup with 15:1 CR. I personally don't want to run Alcohol because of maintenance you have to go through, and this guy didn't preform much if any on the motor as seen on the crank. I just don't want to have to flush the motor everytime you run it for a day or weekend. There is enough to do with changing oil, filter, gas filter, transmission oil..................etc., etc. So, running 116 or 118 race gas is just easier for me personally, and although alcholo is cheaper you use about twice as much. I know a lot of guys are doing it, but I've been racing for some 30+ years and am just to ole and stuborn to change. The cam seems act well with this motor, and although I will short shift at 6500 or maybe a little more................when I did the 9.801 I had taken the throttle stop off and shifted at about 7300...........and the car was still pulling through the traps. I saw the time slips when the owner was racing in the 1/8 mile and everthing was the same except he had 5:89 gears instead of the 4:56's that in it now.......and his was in the very low 6's. So, although I am freshening the motor and the trans is also fresh, I just want to race until my next motor is finished sometime late next year. And don't want to go out and destroy the motor by running it 7500+ with a two bolt main block............although it is a 72 and is a lot stronger in the main bearing area than newer 75 and above motors................I just want to go out and have fun. As for the timming..................36 is what I had when I did the 9.801. So, we will see what kind of numbers it turns on the dyno after going back together.
Rick, E85 is certainly interesting, but my current motor with 15:1CR.....E85 just just doesn't have enough octane to make it work. I believe that E85 is about equal to 102 and I need to burn at least 114.......... I have heard a number of the blower/supercharger guys switching over, especially the guys taking a 10.5CR injected motors and turning it into blower/supercharger motor with E85. One thing about E85 is that you need somewhere around 40%+ more fuel flow.............this lends itself to injection a lot more than a carb'd motor............................................... I believe to really make HP you would have to build a motor from the ground up to take advantage of the E85...............IMHO
With you only wanting to turn 7000 are you sure your not over carbed? I would think it would hurt your low end depending on your lanch RPM.
Robbie, Launch with the trans brake is 5000 on a loosened converter. With the 4:56's and 2spd Glide I go through the traps at 6700rpm, depending on where I shift. When I went 9.8 I shifted at 6500rpm and just don't remember what the tach was reading because the end of the strip was coming up REALLY fast.............and with drum brakes on the front and no chute................we, I was only paying attention to field at the end of the strip.................but I can tell you with the old 1000cfm mod'd car it was still pulling at the finish line.
Yes, as I mentioned these are old heads, but seem to get the job done, and I'm not out to be competitive (been there done that years ago) and just want to go out and have fun. Now with that said the replacement motor I will be putting together hopefully towards the end of next year will be a little more stout, and I will probably be using CHI heads. The heads I have have never been welded although the exhaust ports have been reshaped and they do have beryllium seats. So, yes these are outdated heads no doubt, but they did put the car into the 9's and that is quick enough for me. I have never run alcohol although I have a number of friends that race sprint cars and drag cars on the stuff and they are always telling me the steps they take after a raceweekend, so this is the only thing I have to go by; again, I am taking this directly from what the drag race friends have told me, but they only buy enough Alcohol for the weekend since it is hygroscopic and will start to absorb water, after each raceweekend they drain the whole fuel system and flush it by using gasoline, both the drag guys sprint car guys say they always tear the complete fuel system down at the end of each year to check/rebuild............so this is the only thing I have to go by. As for the oil changing every 50 races, well, everyone has their own schedule, since I have been drag racing (which is over 30 years) I have always changed the oil after every event, be it a one day/two day or even three day race, and the trans and rearend are changed at least 2/3 times a year. I think one reason this old 408 lasted for such a long time (over 12 years) is that the oil was changed so often........along with the filter. Maybe when I have the other motor finished I will borrow a friends alcohol carb and run some through the car for a weekend to see what happens, and if it grenades.................at least I have the other motor to put back in. Thanks for your comments, john
i think you should read a little more into it. there are guys switching to E85 so they can run the high compression on the street...15:1 on the street without over heating or pinging in 100+degree heat. E85 is really impressive if i had easier way of getting it i would be all over it...and it is only a 30% increase in usage. i know a guy in so cal that builds E85 carbs for like $350.00 if you supply the carb. and at $1.85-2.50 a gallon its cheaper than $7.00-11.00+ bucks for race gas. and the tunning window is huge with is, it reminds me of diesels because the more jet/fuel you put into it it seems to make more power...cool stuff. and to add all it is, is bigger jetting for the difference in burn. dont know what you have for a fuel pump but an aeromotive A2000 is more than sufficient.
Ok, I will see what I can find on E85. One thing to remember is that this is strictly a race car and will never see the street. I have never heard of a street motor running 15:1CR, not saying they are not out there, but why would anyone want that much compression when they can run a supercharger or blower and make more HP with less compression. Compression is kind of two edged sword, and with a 15:1 motor you are always worried about hydraulic lock not to mention it gets to be pretty spendy to buy the pistons/heads/O ring the block/rings and ect., plus if you get too much fuel in the cylinders..............it doesn't take much to destroy a motor, although it is harder to do with a carb'd motor than an injected motor, been there and done that! So, I guess the only question I have is that if E85 is equal to 102 octane, how will that support a 15:1CR motor? Also, here in NorCal I have seen very few E85 stations.
it is better than 102 its more or less like c/q16 from what i've heard, not sure where you are getting the info but check out ProE85.com and go to the forum you will see what im talking about...great knowledge about e85 on that sight. and im not saying that people are purposely building 15:1 motors for the street for e85 im just saying people have tested 15:1 and 16:1 motors on the street to see how they would hold up. They run cooler and have great street ability. just a thought... and i would just fill up barrel's of the stuff and store it. thats what im going to have to do. and when you want to have that carb done to e85 just let me know ill give you the info for the guy.