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  #1  
Old 11-04-2001, 02:51 PM
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Default turbo small block

its to my understanding that a turbo motor doesnt like excess of the 3 c's (compression cam carb)
my solution is to use a set of large chamber heads. i believe it is the x or j head or something that is open chambered and has about 72cc chambers. im looking for a vendor of new/fresh iron head that has large chambers, stainless valves of at least 1.88"/1.60", springs that can handle the cams mentioned below, bronze guides, and a 3 angle valve job would be nice and they must be cheap. so who? where? how much? any other info? im shooting for 8.5:1 which can be made possible with off the shelf pistons that should yield a higher compression.

which of these cams is best suited for a 318? 360? the motor will be primarily street as the nearest drag strip is 100 miles. it needs some what decent mileage and some what streetable manners. it is going into a 1986 1/2 ton with tf 727 and 3.23 gears. low end isnt really a issue but mid range is (i can live with soggy corn flakes as long as when i hammer down it moves). i dont plan on taking it past 6000 rpm ever.
these are all ground on 112 degree lobe separation www.hughesengines.com
HE0914AL 252°/260° 208°/214° .458/.470
HE1423AL 260°/270° 214°/223° .470/.504
HE1923AL 266°/270° 219°/223
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  #2  
Old 11-04-2001, 03:19 PM
dewme5 dewme5 is offline
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if you are going to turbo. I can show you places where there are guys running some 10's, and on 9. ON A STOCK 302 in a mustang. The best way to sum it up. Build the motor for 3000rpm and less ZERO over lap on the cam. Build all the low end torque that you can. 8.0:1 or 8.5:1 should be good. Throw in the good felpro head gaskest with the steel fire ring (#1008) for the small block. 500 - 600 cfm carb. of the 3c's, the only one that you need alot of, is FUEL!! DO NOT RUN LEAN UNDER BOOST!!!!! instant death. run rich and bog down. run lean and blow up. if you build the motor for 3000rpm and down.. the turbos will take over from about 2500 - 6000 no problem. (properly sized) Also.. gears. Turbos make so much extra torque, and you can run 2.94-3.23 with no problem on a car with 28" tall tires. Problem with alot of the guys running twin turbos (same setup that I have, only on 351's and 302's, is that with anything above 3.00 gears, they just couldn't break the 130 mph barrier on the 1/4. so they started dropping into the 2.8 and 2.9 range. and started hitting about 133mph. THATS IN THE 1/4 MILE, ON BASIC SIMPLE 302's!!!!!!!!!!!

http://www.geocities.com/toohighpsi/index.htm

check out the capri. and a few others on this site.
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  #3  
Old 11-06-2001, 04:39 PM
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well does any one have a suggestion on a build up as far as a 318 would be? or a 360? i have a stock roller cam 318 with the 302 heads (polite way of saying 80s smogger crap) it also has the 8.5:1 cr i think (according to chiltons) i believe that the stock combo may even be too mild for turbo engines. no? it seems like i should at least use stainless valves due to the aggressive exhuast temps. that would require stepping up to 1.88/1.60 valves. at that point im better off buying something like aerohead or something (i cant find any contact info or web site for them or any other supplier) also it seems the motor could benifit from a dual pattern cam. no? intake will be torker style adapted to efi. that means for the best performance i should swap in the 340/360 heads since the #302 have smaller ports causing a restriction am i right? if i swap in the 340/360 heads will my compression drop too low requiring higher compression pistons like 9.5:1s or something? and then theres head gaskets. fel pro or copper? im willing to take all input pushed my way. ill prolly use the 318 as i all ready have one. any one have power figures along with engine combos?
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Old 11-06-2001, 05:09 PM
turbododge turbododge is offline
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As Dewme said, stay tame on everything except fuel. Small cam and small valves are good, going to bigger valves will actually hurt you. Split duration, heavy to exhaust will help a bit, but as was said, NO overlap at .050, use a 114 centerline and reasonalble lift. The old RV cams are very close to what you want. Stainless valves will make it live longer, as well as hardened seats. Cast pistons are very iffy unless you stay under 6 to 8 psi and NEVER detonate.
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  #5  
Old 11-06-2001, 05:19 PM
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any one know of a source of 318 stainless valves?
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Old 11-07-2001, 10:41 AM
dewme5 dewme5 is offline
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maybe just run 360 heads. and then cut back on the intake even more.. you do need all the exhaust that you can handle.
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Old 11-07-2001, 12:54 PM
Karl43 Karl43 is offline
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Mancini Racing sells stainless steel 340 valves for about $150.00 in the last flyer that I saw. You could always have the valve holes in the head opened up to take the larger valves. I'm not sure if they carry them in the smaller 318/273 valve size. They sell 340 stock valves for $99.00 for both intake and exhaust valves. They usually stock 340 valves and sometimes have to order the smaller 318 stuff as it doesn't sell as fast.
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Old 11-08-2001, 05:23 PM
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LA360Dart LA360Dart is offline
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Hello All;

A friend built a turbo'd 340 for a 69 Barracuda tubbed the car and ran 11.60's. The amazing thing was he used a stock 340 cam and 72 up stock 340 pistons. He studded the heads but used the stock bolts for the crank. He played with turbo size until he got the power where he needed it. The rear end gears he ran 3.55 and 727 with a 2400 rpm stall. It was a pull thru system. He started with a small turbo and increased the size.

Denny
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Old 11-08-2001, 09:14 PM
dewme5 dewme5 is offline
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a best of 11.60's?? seems a little slow for what it should be capable of. dropping down on the gears might help for that. some where around 3.00's. With my 2.94's, my car was puling harder in first than it does now with the 3.23's. .. only in first gear though. something to do with spool up time, and just about over running the turbo. it's busier playing catch up than actually putting the power down. also though, with the 2.96 first gear that is going to make my problem a little different.. But still, a 340 with 10 pounds of boost should be able to break into the 10's
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Old 11-08-2001, 11:30 PM
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ok how would i select a converter? the gn guys have picked up to .7 seconds in the 1/4 by using better lock up converters. they are made by vigilante have 5 clutch disks in them and lock up from 2nd gear on up. it seems to produce higher boost by loading the engine more. they have such a converter for the 727 and it runs about $750. i dont know how you put a lock up converter in a standard tranny as that would require major surgery??? maybe ill ask the tech guys.

also beings thats i gots a truck which rear end should i use? they all have there flaws. the stock 8 1/4 comes in all ranges of gears and has the standard 5.5x5 bolt pattern but is "weak-knee'ed" the 8 3/4 has third member, wide range of gears but comes in the small 4.5x5 bolt pattern and isnt the ultimate in rear ends. the dana 60 has ultimate strength but its lowest gear is 3.54/55 and only comes in a 8 lug pattern. so many trade offs so much confusion. maybe i outta just test the "brute strength" of my current 8 1/4 and see what some real torque will do to it?
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  #11  
Old 11-09-2001, 02:31 AM
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I will argue the strength of the 8 3/4 as stong enuff for what your doing. The may not be the ultimate rear, but, there plenty strong. They were behind HEMI's stock. The DANA is stronger and what should be behind a HEMI. But it's not what was allways there.
The bolt pattern is not a draw back at all. Rather common if anything. If you want to get a 17 inch rim for a 8 3/4's 4.5 bolt size, just order it from the manufaturer of the rim. I have seen freinds come up with new styled rims for there 13 inch rim, Chevy Vega with a phone call. Don't let anybody BS you into "They don't make it for that" line. It's only half true. You see, they might not make it, but you'll take it like they can't do it. They can and will!!
Also, you can contact MOSER or other axle manufactures to make you a stronger axle if you think it's not up to par. Which also leads me to the DANA. Again, last sentence, now only for the DANA. Instead of 8 lug, order up 5 or 6 lug in the spaceing that you wish.
Good luck
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  #12  
Old 11-09-2001, 05:37 PM
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ok so if i use a 8 3/4 can they redrill for my 5.5x5 bolt pattern? if i use a dana 60 is there any benifit/drawback to the full floaters found on many older trucks? are the 8 3/4 truck rears full floaters?
i forgot about the 9 1/4. is it any good? i could use a ford but i dont like the idea of having to redo the whole rear (springs shocks length all that) when there is a wide variety of mopar rears with the right length and shox and spring perches enabling a "true bolt on"
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  #13  
Old 11-09-2001, 11:16 PM
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Best bet is to check with the axle manufacturer about how things are done. The 8 3/4 has an advantage over the others in 2 ways.

1. Easy to change ratio's via taking out the center section. EX; A buddy has 3.55's and you want to try them out over your 2.76 ratio, before you purchase a set of your own. You change out the pumkin in about 2 hours (If your fooling around) with your buddy. Your 2.76 ratio center section pops right out and the 3.55's pop right in.

2. NO "C" CLIP! When you beat on the car, the side loads can break the "C" clip and your axle with wheels and brakes slide right out of the houseing onto the floor spinning you around and around like a top. I have seen this live during a drag race. Axle fail occured around a bend (Mild at that) at speeds over 120 mph. The car looked like a firework called a Ground bloom flower.

The 8 3/4 is the smallest rear I would use. The 8 1/4 is fine for mild build ups. Under 400 hp. I truly do not know the limits of that rear. The 9 1/4 is stronger via ring gear size and so on up the scale. You may have to customize any rear you end up gettin unless it came in the car/truck your working on. If your truck came with an 8 1/4, find out if it had an option of a 9 1/4 rear. Or, if they can be an easy no brainer swap.
Take the time for a tape measure with a friend and write down the measurements of width from drum to drum, spring perch to perch and shock positions to make it easy when looking for a replacement.
A good way to find out what was an option on your truck (this is what I do for my rides) is to go down to the dealers parts counter or warehouse parts dealer (I go there, the sell MP parts ) and ask about it. You will be surprised to find out what came with what. Not to mention, whats still available new.
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Old 11-10-2001, 11:08 AM
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well i do know that trucks came with almost all rears except the 7 1/4. there were 8 1/4 8 3/8 8 3/4 9 1/4 9 3/4 (dana 60) 10 3/4 (dana 70) and i think even one more. well ill look around for a good housing. which center section do i want? i think they came with 2 basic castings and one was much stronger?
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