Check you real comp. ratio.
Disappointed with my engine
- Thread starter Retroboy
- Start date
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Rat Bastid
Dunamis Metron
That cam is wrong for zoomie headers. You’ve killed all the power because you have killed any flow at overlap with those headers. You need a good, tuned header with the proper size and length collector. The other thing I see is that carb hat. I don’t know how many square inches the opening is, but it’s too small. Also, with that style of scoop you run into an issue where that scoop will pressurize the vents and it will go dead rich. You’ve got issues, but most are easily corrected. And the carb is killing you. A vacuum secondary carb is for guys who can’t tune. There is a real possibility the secondaries don’t even fully open.
Bobzilla
Well-Known Member
I don’t see a water pump or cooling system in the picture. Is that running on alcohol?
No offense but is that engine even planned? It sounds like you threw together a whole bunch of parts and nothing is matching. J heads with a 5k stall and zoomie headers ?
Look at the intake and a 360 rpm is good to 6k with out internal balance. Sure you can go higher but they don’t like to rev beyond without real work. 360 make a lot of low end torque but HP comes from high revs and you have a lot of bottle necking going on. I’ve built a few 360 for the track in a Demon that weighed 3132 that was 5 gals of fuel and me. 430 rear and 28” x 8 slicks. 69’ 833 4 speed with low first.
12.2 consistently and my reaction times back then was really good- no so much now at 51. Last 360 I built was 441hp at 6200rmp and 426.5 ft lbs at like 4500 if memory is correct. 10.74-1 compression and thermoquad carb.
Anyhoo- don’t expect that engine to run huge HP with out a real plan. You build the whole car not just an engine.
Keep us posted.
Look at the intake and a 360 rpm is good to 6k with out internal balance. Sure you can go higher but they don’t like to rev beyond without real work. 360 make a lot of low end torque but HP comes from high revs and you have a lot of bottle necking going on. I’ve built a few 360 for the track in a Demon that weighed 3132 that was 5 gals of fuel and me. 430 rear and 28” x 8 slicks. 69’ 833 4 speed with low first.
12.2 consistently and my reaction times back then was really good- no so much now at 51. Last 360 I built was 441hp at 6200rmp and 426.5 ft lbs at like 4500 if memory is correct. 10.74-1 compression and thermoquad carb.
Anyhoo- don’t expect that engine to run huge HP with out a real plan. You build the whole car not just an engine.
Keep us posted.
K.O. SWINGER
Meeting in the alley since 1976
I am no professional engine builder or am I a hardcore track racer, but when I started advancing my cams 4° on similar builds it woke the whole motor up like a lot!
I can move and merge. The same guys will respond to this thread that responded to the last one. We see all the threads.
don’t even start comparing a stock Mopar head to a stock Ford head. Lol. Cleveland is a story of its own. Get an aftermarket aluminum head and clean it up some and you will find your missing ET.
This is what jumped out at me:
- Factory iron heads that have been "cleaned up some"
- 870 Vacuum Secondary that "still needs some tuning"
Retroboy
Well-Known Member
No mate dry block. Yes gets hot.
Retroboy
Well-Known Member
904
Retroboy
Well-Known Member
Tell me more about this pressurizing the fuel bowls/vents idea.
Years ago we ran one of those tall econo dragster scoops sealed tight and picked up 3 tenths and 6 mph (1/4 mile back then). We didn't make any change to the carb.
Retroboy
Well-Known Member
Thanks for your input. A Slingshot is nothing like your heavy door cars to run. Time and tine again it's been shown headers make no difference to ET over Zoomies. For a car that's just for fun like mine, converter selection isn't as critical as it is with your heavy tin tops - we just don't have the mass to shift off the line and we don't have suspension and stuff to think about - we tune the lauch with tyre pressures wheelie bar adjustment and the addition of some weight on the nose depending on the track. In the early 1980's I ran one of the popular at that time tall econo drsgster type scoops which was sealed tight and picked up three tenths and 6 mph but the suggested pressurization of the vents/ fuel bowls is something I'll look further into. Wonder what the blow through turbo guys do ??? Moving to Chrysler has been a learning experience - I've learnt the hard way that the oiling system needs a bit of thought to keep bearings and crank in nice shape. Pity about the heads. I do get it - they're like a gaint kink in the garden hose.
Thanks for your thoughts
Cheers
Thanks for your thoughts
Cheers
I agree the engine sounds like somewhat of a mismatch, but I also agree that there's more in the chassis setup. Get the 60ft times dialed in and see what the best is then. Then if you want more, I think the engine is where to look. It's always cheaper and easier to "work with what you have" first.
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I see you're in SA? people have gone pretty fast with stock heads so don't worry about that. I would look at the carb/ignition and tune before you even think about spending any money on new parts. Go find an old (yes old) 650 or 750 DP with stock jetting and start from there and make sure your leads are good and the advance curve is right. People expect to bolt parts together and then magically believe the engine will make a predetermined number, sometimes that happens and sometimes it doesn't. If you cant make 400 HP with a 360 with those parts something is wrong and its got nothing to do with the heads.
Good luck.
MOPAROFFICIAL
Oogliboogli
The intake sucks , the carb is probably a little too big.
The heads could be a problem too 'if at the very least 'the valve job isn't good.
You could blame the heads or you can blame the cam...'The head does not flow as cast or without porting Beyond .490 to .500.'...
But I blame the guy who put it together and picked those parts more so LOL no offense. You should go with something around .500 to.520 and 300's duration with [email protected] w/ 106-108 lsa.
K.O. SWINGER
Meeting in the alley since 1976
Yeah granted small block Mopar heads are not great when compared to a modern cylinder head but one of the best small block heads available when they were built . Why are you running a small 194?
check all the basics.
Check what the real compression is.
May not be a perfect combination of parts bu that thing should make a bunch more than 300 hp there is a whole heard of horses running free somewhere just waiting to be roped in.
Check what the real compression is.
May not be a perfect combination of parts bu that thing should make a bunch more than 300 hp there is a whole heard of horses running free somewhere just waiting to be roped in.
MOPAROFFICIAL
Oogliboogli
194 valve can flow up into the 260s no problem.
K.O. SWINGER
Meeting in the alley since 1976
Sure what's your point? Anything a 194 can do a 202 can do better except for maybe cost more money to get there.
MOPAROFFICIAL
Oogliboogli
So bigger is better... that's your answer.
A whole lot less work to get about the same average flow with a 194 in that port but I guess you'd have to do that a lot to know.
A 2.02 cut in without proper work will flow less than a 1.94 cut in without proper work.
Now go tell him to get a mountain motor, mr.bigger is better!
K.O. SWINGER
Meeting in the alley since 1976
news bulletin from Mopar orifice everyone should downsize their intake valve for better performance get flipping real. Oh that's right you're the only one that knows s*** around here right right.So bigger is better... that's your answer.
A whole lot less work to get about the same average flow with a 194 in that port but I guess you'd have to do that a lot to know.
A 2.02 cut in without proper work will flow less than a 1.94 cut in without proper work.
Now go tell him to get a mountain motor, mr.bigger is better!
MOPAROFFICIAL
Oogliboogli
1st off, you're a ******* idiot for calling names. You already lost.
You are asking why he doesn't have 2.02 valves... answer= because he doesn't need them for his goal and can make 500 and some-odd horsepower with a 194 valve already... so what the **** do you know, nothing. Soo Stfu and kick rocks all the way back to your van down by the river. Clown mthrfkr..
MOPAROFFICIAL
Oogliboogli
Because you couldn't pick the right cam for it. LOL You piss into the wind ..and if you don't catch it in the face... you call it a success!
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