i guess i should of put car weight is 3200 pounds running 91 octane my whole goal when i built this was to run pump gas why i had to go for 10.35 :1 compression
521 sr-71 headed motor
so i built a 521 with e sr-71 motor is a bust . thought it would of had a bit more power. 6.8 rod 4.3 stroke 4.39 bore 38cc dished piston too run on pump gas chaved 30 off the heads cam 272 int 280ex 731int 727 exh 109 lsa have the cj-v intake with a 1050 dominator 27 to 28 timing best 60 ft is a 1.6 with 4.88 final gear a c6 trans not sure if my converter is missmacthed now . any ideas thanks
1 - 20 of 21 Posts
Looks like a bit of mis match components. Appears compression is a little low for a cam that large. Intake is pretty large also. I would say you probably need a little more timing. The converter will really kill an engine also. Not bashing your set up I would just revisit cam/compression thoughts
dont think you are bashing i am here to learn and better my setup .
ya i have tried 30 degree timing and seems i get "(engine run on up there") (dieseling " what ever you call it . i called roger at kaase and he said 30 and under on the timing . ya i would of rathered compression in the 11:1 range but i could not get off shelf pistons for this build i am not apposed and going to differant pistons if i need to now. my old 501 in the car would run a 1.6 60ft and had a 254 258cam .647 lift and i had a 950cfm carb on it . i wonder if i should try my old intake and carb on it ? anybody want to chim in on the engine timing as well . please do thanks
ya i have tried 30 degree timing and seems i get "(engine run on up there") (dieseling " what ever you call it . i called roger at kaase and he said 30 and under on the timing . ya i would of rathered compression in the 11:1 range but i could not get off shelf pistons for this build i am not apposed and going to differant pistons if i need to now. my old 501 in the car would run a 1.6 60ft and had a 254 258cam .647 lift and i had a 950cfm carb on it . i wonder if i should try my old intake and carb on it ? anybody want to chim in on the engine timing as well . please do thanks
Not enough static / too much cam
Intake is overkill
Timing appears correct
More stall and gear might help. You don't mention your convertor stall.
You've moved your power band up apparently with out addressing stall and gearing.
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Intake is overkill
Timing appears correct
More stall and gear might help. You don't mention your convertor stall.
You've moved your power band up apparently with out addressing stall and gearing.
Scotty J. "AKA" The "Mad Porter"
"EMC 2006" 3rd place finisher
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one more thing i should state ifNot enough static / too much cam
Intake is overkill
Timing appears correct
More stall and gear might help. You don't mention your convertor stall.
You've moved your power band up apparently with out addressing stall and gearing.
i could go back to my edelbrock intake if it will help not sure how i can bump my static compression on this combo now , might have to go to a mahle piston 93021890-2 4.1cc flat top only problem is these are 40 grams heavier and would need to rebalance crank which is hard to get done around here as all the shops are months booked up . i might just run my 501 flat tops and cut valve reliefs in it but my compression would be high 13's so would need to run higher octane boost or c14 or something my whole plan was to try get away from race fuel and goal was 700hp but this engine is not there like 550hp is my guess.
what gear you thinking if a 4.88 cannot get better than a 1.6 than going to like a 4.56 or 4.10 would just slow it down would it not? i dont have a trans brake all i have is a 2800-3800 stall hense why i said maybe my stall is no good i have been street driving car for few years and has not been run at track for like 5 years so ? any ideas thanks
Scotty J. "AKA" The "Mad Porter"
"EMC 2006" 3rd place finisher
Ported BBF iron head specialist & Aluminum heads from all sources.
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Not enough static / too much cam
Intake is overkill
Timing appears correct
More stall and gear might help. You don't mention your convertor stall.
You've moved your power band up apparently with out addressing stall and gearing.
Scotty J. "AKA" The "Mad Porter"
"EMC 2006" 3rd place finisher
Ported BBF iron head specialist & Aluminum heads from all sources.
Custom ground cams
See our products in the Vendor for sale section
Customized crate engines
ParklandAutoMachine.com
R-H-P.biz
"Parkland Performance Auto Machine" Formerly RHP
(253)-988-6648
Parkland Auto Machine
Not enough static / too much cam
Intake is overkill
Timing appears correct
More stall and gear might help. You don't mention your convertor stall.
You've moved your power band up apparently with out addressing stall and gearing.
one more thing i guess i should mention is i have full exhaust on the car 3" pipe and has mufflers you think this could be killing power as well . ?i could put dump valves on the exhaust right off the header if it would help?
Scotty J. "AKA" The "Mad Porter"
"EMC 2006" 3rd place finisher
Ported BBF iron head specialist & Aluminum heads from all sources.
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Tell us your complete engine build specs
Also your converter stall size.
4.88 gears, you running 1/8 mile.
Was engine ever dynoed?
What's your rear end consist of?
Cheers, Bob
ps- there will be a new intake to the market stay tuned!!
Also your converter stall size.
4.88 gears, you running 1/8 mile.
Was engine ever dynoed?
What's your rear end consist of?
Cheers, Bob
ps- there will be a new intake to the market stay tuned!!
engine build is as followsTell us your complete engine build specs
Also your converter stall size.
4.88 gears, you running 1/8 mile.
Was engine ever dynoed?
What's your rear end consist of?
Cheers, Bob
ps- there will be a new intake to the market stay tuned!!
4.3 stroke lunati forged crank
6.8 mahle h beam rod
mahle 930245690 pistons -38cc dish 1.35 com height
1.73 rocker custom kaase sr-71 heads shaved 30thou aprox 65cc chamber .
useing the 1028 felpro head gasket 4.67 bore .041 comp thickness 11.4cc comp volume
camshaft is the one kaase spec'd for me which is a 34-000-9 grind # 4148r/4329r r 109.0
.731 int lift .727 exh lift
duration @ .020 tappet lift 304 int 310 exh
valve timing @.050 int open 27 btdc close 65 abdc
exh open 69 bbdc close 31 atdc
duration @ .050 intake 272 exh 280
i degreed cam too the cam card and everything was bang on.
elimnator cj-v intake
the carb is a 1050 2 circuit dominator 84jets front 85 jets back i might go 1 jet size bigger as i am seeing could be a hair leaner than i like plug not bad would rather be safer than sorry
distrubeter msd pro billet locked out
msd 6al
rear end is a 4.88 9inch 4 link with a full spool . i am running a 33"slick 12" wide they hook good so do not need to go wider my street tires are 33x19.5
i never dynoed engine and i am wondering if my power is higher rpm. most my runs were shifting 5500 too 6000 and crossed the line @ 6100 120ish mph
i thought i would run out of gear and be higher rpm so thought i would need to change my gears .
no i am running 1/4 mile
converter not sure brand but it a 2800-3800 spec from previous owner of car but ? it is a 12" converter
i think i might need to rev this thing higher and run a bigger stall like a 4500i do drive on street so dont want it to heat up to much . it runs down highway at 68mph and aprox 3600rpm
car weighs 3180 pounds without driver and i am 200 pounds
i was hopeing for 60ft times in the 1.4 or even 1.45 was hoping for right around 10 second with this combo.
Well the converter is completely wrong, need min 5000k stall converter.( that's why your 60ft sucks)
You need to shift 7000k min.
This engine should be making at least 800hp and running low to mid 9s @3200lb
Cheers, Bob
You need to shift 7000k min.
This engine should be making at least 800hp and running low to mid 9s @3200lb
Cheers, Bob
well drag racing is new too me . so i a a noob . good mechanic not so much driver. i will look for a converter, where is a good place to buy converters from if ia buy one would like to buy a good one. wow did not relise i could rev this engine that high ..Well the converter is completely wrong, need min 5000k stall converter.( that's why your 60ft sucks)
You need to shift 7000k min.
This engine should be making at least 800hp and running low to mid 9s @3200lb
Cheers, Bob
i meant 95 jets in the backengine build is as follows
4.3 stroke lunati forged crank
6.8 mahle h beam rod
mahle 930245690 pistons -38cc dish 1.35 com height
1.73 rocker custom kaase sr-71 heads shaved 30thou aprox 65cc chamber .
useing the 1028 felpro head gasket 4.67 bore .041 comp thickness 11.4cc comp volume
camshaft is the one kaase spec'd for me which is a 34-000-9 grind # 4148r/4329r r 109.0
.731 int lift .727 exh lift
duration @ .020 tappet lift 304 int 310 exh
valve timing @.050 int open 27 btdc close 65 abdc
exh open 69 bbdc close 31 atdc
duration @ .050 intake 272 exh 280
i degreed cam too the cam card and everything was bang on.
elimnator cj-v intake
the carb is a 1050 2 circuit dominator 84jets front 85 jets back i might go 1 jet size bigger as i am seeing could be a hair leaner than i like plug not bad would rather be safer than sorry
distrubeter msd pro billet locked out
msd 6al
rear end is a 4.88 9inch 4 link with a full spool . i am running a 33"slick 12" wide they hook good so do not need to go wider my street tires are 33x19.5
i never dynoed engine and i am wondering if my power is higher rpm. most my runs were shifting 5500 too 6000 and crossed the line @ 6100 120ish mph
i thought i would run out of gear and be higher rpm so thought i would need to change my gears .
no i am running 1/4 mile
converter not sure brand but it a 2800-3800 spec from previous owner of car but ? it is a 12" converter
i think i might need to rev this thing higher and run a bigger stall like a 4500i do drive on street so dont want it to heat up to much . it runs down highway at 68mph and aprox 3600rpm
car weighs 3180 pounds without driver and i am 200 pounds
i was hopeing for 60ft times in the 1.4 or even 1.45 was hoping for right around 10 second with this combo.
well drag racing is new too me . so i a a noob . good mechanic not so much driver. i will look for a converter, where is a good place to buy converters from if ia buy one would like to buy a good one. wow did not relise i could rev this engine that high ..
The torque converter is probably the most important part of a drag race deal. Good luck on getting the proper converter first try. Yes you can rev her on up.
Where exactly is the cam phased/ICL?
109 intake centre line .Where exactly is the cam phased/ICL?
Given the modest static c/r and monster intake...109 intake centre line .
With adequate intake valve PtoV clearance I'd advance that cam 4* to a 105 ICL
Scotty J. "AKA" The "Mad Porter"
"EMC 2006" 3rd place finisher
Ported BBF iron head specialist & Aluminum heads from all sources.
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ya when i assembled engine if memory serves my i had lots of clearance . you think i would need to recheck with clay again ?Given the modest static c/r and monster intake...
With adequate intake valve PtoV clearance I'd advance that cam 4* to a 105 ICL
Scotty J. "AKA" The "Mad Porter"
"EMC 2006" 3rd place finisher
Ported BBF iron head specialist & Aluminum heads from all sources.
Custom ground cams
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You need a minimum of .080" @ about 15* ATDC
A cam this large is chasing the piston down the bore after TDC.
You need to check either via clay OR light valve spring checking at TDC 5 10 15 ATDC
Scotty J. "AKA" The "Mad Porter"
"EMC 2006" 3rd place finisher
Ported BBF iron head specialist & Aluminum heads from all sources.
Custom ground cams
See our products in the Vendor for sale section
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ParklandAutoMachine.com
R-H-P.biz
"Parkland Performance Auto Machine" Formerly RHP
(253)-988-6648
Parkland Auto Machine
A cam this large is chasing the piston down the bore after TDC.
You need to check either via clay OR light valve spring checking at TDC 5 10 15 ATDC
Scotty J. "AKA" The "Mad Porter"
"EMC 2006" 3rd place finisher
Ported BBF iron head specialist & Aluminum heads from all sources.
Custom ground cams
See our products in the Vendor for sale section
Customized crate engines
ParklandAutoMachine.com
R-H-P.biz
"Parkland Performance Auto Machine" Formerly RHP
(253)-988-6648
Parkland Auto Machine
yes light spring thats what i will do thanksYou need a minimum of .080" @ about 15* ATDC
A cam this large is chasing the piston down the bore after TDC.
You need to check either via clay OR light valve spring checking at TDC 5 10 15 ATDC
Scotty J. "AKA" The "Mad Porter"
"EMC 2006" 3rd place finisher
Ported BBF iron head specialist & Aluminum heads from all sources.
Custom ground cams
See our products in the Vendor for sale section
Customized crate engines
ParklandAutoMachine.com
R-H-P.biz
"Parkland Performance Auto Machine" Formerly RHP
(253)-988-6648
Parkland Auto Machine
Given the parts combo you're working with, the 109* ICL is wreaking the most havoc on your engine's performance. I might advance that cam to 104* ICL--then watch your enigne performance improve.109 intake centre line .
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