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Calling Racer X #99
Hi Racer X,
The new dart block has me hooked and I noticed that you are into a build; I am assuming you are using the new Ford Iron Eagle block. I have gone thru a number of build scenarios in my head, all with a 4.185” bore and various strokes. Currently I’m thinking 3.50” stroke and the right innards to turn 8-9,000 rpm’s. Anyway I would love to know what you are building and the goals you are shooting for. Any discussion would be appreciated. Thanks, Joe |
It's about time
Glad Bob asked for this Forum.
Joe, I would love to tell you all about my new Dart sb but since you are from the NY area you will certainly understand that If I tell you everything than I would have to Kill you.;) Ok now to get serious. Standard 4" bore Standard 3.5" stroke Forged crank Forged Rods Forged pistons 12-1 comp Very agressive solid roller cam ( custom grind) AFR 205 heads Victor Junior manifold (about the only thing that survived) Demon 750 ( also a survivor) Shooting for 550 + hp Hope this Helps RD BTW , If you start out with the 4.185 bore what are you gonna do at rebuild time? |
I am having Keith Craft build a 4.125" x 4" dart block internal balance with Scat crank and rods, AFR 205 heads, Comp cams 282 HR cam with victor jr and demon 825 carb. Should be about 550 HP over 500 ft-lbs. I am having them dyno with complete exhaust system including mufflers.
Should be ready by Christmas. |
Re: It's about time
Quote:
GS |
Racer X,
That's funny. At our engine builder there is a new dart block thats going to be assembled exactly the same way as yours with a slightly used Victor Junior Manifold sitting next to it, waiting to go on top. Glenn |
Cranky:
Did you look at he Edelbrock Victor Jr. heads? If so, curious to know why you chose the AFR's over them. Some day I will graduate to a GT40 and want to learn more about small blocks. Please don't tell anybody I said small block. :3DSMILE::3DSMILE::3DSMILE: |
Jeff - those AFR205 heads outflow the Vic jr heads significantly out of the box. On my own tiny block, swapping from the Edlebrocks to the AFR's would, in theory, according to desktop dyno, gain me 50 hp and lbs ft. Mainly 'cos strokers like good head flow figures.
In practice, I am going to take the existing heads off and give them a good porting job to get the same result for much lower $$$s. |
Racer and others
Racer X and others,
I understand just make it quick and painless…….O btw can you wait until after I use your secrets build a motor and play with it awhile? My engine builder lover the AFR 205’s they were on my list before the block. I’m thinking large bore and short stroke for high rpm’s……anyone have ideas on cranks that will live at 8-9,000. I was considering billet but am starting to price myself out of a new motor. P.S. I’m wondering if the larger bore will unshroud the valves and help the breathing…any thoughts? Thanks all Joe |
Joe,
Yes the larger bore will do just that. I don't know how tough the the new Ford block is with regard to the cylinder walls but if it's like the GM aftermarket blocks it should not need to be rebored at rebuild time due to wear. My builder encouraged me to go with a 4.155 bore over 4.125 to unshroud the valves. They never have to do anything to the cylinders except a light hone at rebuild but if I did hurt it I still have a few bores left. I use Crower's 4340 non-twist cranks, they will handle that easily with the right weight piston. Scott One other thing; at that rpm be prepared for yearly freshens. The valve springs might last 1000 track miles or 2000 street miles. The same with roller lifters. |
Scottj,
Is that crank forged or billet? Any idea of approx. current street price on it. As a thought I could go 4.155" and still have .030" for a clean-up if necessary. Does anyone have an opinion, flat tappet solids vs. roller solids at higher rpm's? Have read of problems with solid rollers on street motors. Thanks all, Joe |
Joe, stay with a stock stroke if you want to crank it up past 7,000 rpm. If you run it over 8,000 rpm, you will need titanium valves, which are expensive and won't last long on the street. I would go solid roller over solid as you can have a much steeper ramp, less duration and more lift. You will probably need to change the valve springs regularly, but they are relatively cheap at under 250.00 per set.. I have a motor similar to cranky's but with yates heads. I keep it under 8,000 rpm and drive on the street as well as the track. Just make sure, regardless of your choices that you use a competent builder that will dyno and break in your motor. If there are any problems, they will catch it before they hand it over to you. I have had good luck with mine for almost 3 years, knock on wood. Scott
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Joe,
I just spoke with Crower, sorry but they recently dropped the non-twist forging for the Ford, its got to be a billet. You probably have these prices but here goes: $1950.00 for std., $2250.00 for LW, and $2775.00 for UL. That's about $500 more than the non-twist was. With the spring pressures required for that rpm any lifter will have problems on the street. You need to keep the rpm's up to keep the lifters oiled since they don't have direct oiling. My engines get new roller lifters and valve springs every year. Don't be suprised if it costs $5-6000.00 in yearly (1000 track miles) maintenance to turn that kind of rpm. That would be new pistons, rings, bearings, roller lifters, valve springs, hone, timing set, gaskets, wet mag everything, and inspect every piece. Don't do it and it's a ticking bomb. Roller lifters will live on the street if you drop the spring pressure and that will limit rpm and make everything live longer. Scott |
Small World, G Gibbs!
I'm on the phone a lot with Jason out there at Keith's----I am leaning toward the same engine. Dart blocks must add a couple thousand, anyway. But....it might be worth it. Any special reasons you chose Keith over others? Appreciate any information....still pondering the choices of engine-builders....:MECOOL:
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Why I would choose Keith C.
I wouldn't hesitate to have KC build a Ford stroker. My reason is because he builds winning dirt Late Model engines as well as being a dirt Late Model racer himself. Dirt Late Models are where the developement is for strokers and he knows the right combinations. Thats why I had ProPower do my engines, they are #1 in the US right now in DLM and they are only 2 hrs from my house.
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OK Ok I'm commin down
I only drink Scotch, non of that Rakki stuff...but maybe i'm drinking to much lately. Based upon what I'm hearing I probably should be sticking to 7,500 rpm or so. Does this sound more realistic on a street motor?? Since I enjoy sportbikes so much I really love those rrrrr's.
I don't mind the heavy maintenance stuff constant oil changes, valve adjustments etc. but expensive rebuilds annually is pushing it for me. Joe |
Joe,
That's what I turn the new motor for the Cobra and I expect to have the same durability that Coyled has demonstrated. |
got snake,
I think Cranky is setting the specs on the motor to spin regularly at 8000 RPM. I will probably have Hoffman build me a twin of Cranky's to replace my broker moder too. |
Beehive Springs
I read an article a few weeks back (can't remember where) about beehive valve springs that Comp Cams have developed. Supposedly they can handle the higher cycle rate of high rpms (less spring harmonics, or something like that) without requiring excessive pressure to prevent valve float. The lower pressure also helps with lifter life.
They were even discussing that with the lower seat pressures that you could get more revs out of hydraulic lifters while preventing lifter collapse. Does anyone have any experience with beehive valve springs? Thanks, Greg |
The reason the beehive spring was designed was to eliminate the need to machine the valve spring pocket. It is the same diameter at of a stock spring on the bottom and gets bigger in diameter towards the top. No other advantage over a normal spring.
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Nope. more to it than that
Jeff,
I'll dig up the article. There were definite mechanical advantages to the beehive springs. Less coil bind, less harmonics, cycle rates, that kind of stuff. I'll post the info when I find it. Greg |
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