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Discussion Starter · #1 ·
New engine setup and am having problems getting it to run a decent number. Dont know where the problem is?

Engine is a 385ci sbf 3 3/4 stroke, .040 bore, non-siamese bore block. Bryant crank, R&R alum. rods, Arius 14:1 pistons. CNC High ports, Ported vic. jr intake and comp solid roller camshaft. .702/.704 lift 275/282 @050 ls: 108 installed w/4 deg. advance. 2x3.5exhaust and currently has a quick fuel 850 on top w/2inch spacer and 1inch plate kit. Race weight 3150. c4, 28inch tire 4.56 gear. Engine plan was to run well on motor and hit it with small amount of nitrous(150-200). I have tried two converters first one went 3500 on brake and current one goes 5200. Engine flat line hards at 7300 and wont pull past. I have tried a 950hp on it, a 1050 dom, and now has a 850 quick fuel. Tried 34deg-40deg timing no mph changes. Car ran quickest w/dominator [email protected] and fastest with 950hp @127mph. W/850 car ran 10.90's @124 and on a 100 hit went 10.14 @132. I feel the car should be alot quicker than what it is and am running out of ideas..? Cyl. head guys said not to put 4 deg. advance in camshaft? Should I put the tight converter back in it and hit it with alot more than 100? Realistically what should it be running.


Thanks for ideas.
 

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Might be a combo problem. Get it on a dyno and see if you have a problem with the power going away ? I see al kind of problems on the dyno that once fixed really improve the performance. As it stands right now the MPH ET seem pretty good so the car is working.
 

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I agree it should be quicker: I know a guy who had an Edelbrock-headed 347 that went 10.90s or better and it didn't quit pulling until something like 8600rpm. I'm not familiar with the "high port" heads - what cc are the intakes?
Retarding the cam should give you better top end.
You've got a 2" spacer AND a 1" nitrous plate? That's alot of plenum.
 

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Discussion Starter · #4 ·
I am putting the car on the dyno thurs. This is why I was hoping for some ideas and things to try. Car seems to work well and et's well for the mph so dont think it's something in the car.

My high ports are a 227cc intake port, use a 2.08 valve and flow a smig over 330cfm @700. It uses a 70cc champer. The intake is just a vic jr but has been welded on and built up about a 1/2 to accept the increase in port size. The intake plenum was also ported and opened up pretty well.

I can try eliminating the 2inch spacer but was told because the intake is only a vic. jr. it's a little shorter than what I should run(super victor). With the nitrous plate(1inch) it increases the volumn to that of a super victor. Then run a 2inch on top of that which seems pretty common and the way to go.

Camshaft wise, is where the engine builer and I vary in opinion. Being on a 108 and advancing it 4 deg. Should make it run better on the motor he says. BUT by advancing it 4 deg. you loose aprox. 100 rpm every 1 deg advance it the general rule of thumb right? So if the camshaft was ground to turn 7800 it's only going to want to turn 7400? To me a naturally aspiriated motor needs to turn HIGH rpm and get the power up there especailly with my short block and heads. So even though you loose the advance by backing up the cam you will pick up the rpm and torque where is needs to be..? And when I touch it with some nitrous it should like the retard even more right? My beliefe is the camshaft is way off but what do I know... I'm no engine builder.


Thanks guys for the input..
 

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Discussion Starter · #6 ·
needs a super vic intake, feed the beast.... at best the vic jr is in the 250-270 cfm range i would think. the choke is in the intake you have, that combo should spin in the 7800-8500 rpm range easy, with that cam and stroke.
Sounds like a possibility and will keep it in mind. Granted it is a vic. jr. but the intake has been worked VERY well. The engine the intake was on prior to mine was same cubic inch(383) different heads and had no problem reving 8,800. His car went 8 teens on 1 kit with this intake so it's hard for me to believe it's the intake.. Engine builder says it should only spin about 74-7,500?

Thanks again..
 

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last windsor i ran was very similar................383 with flatops, exact same heads, 268/276 roller cam, super victor with a 950 carb on 93 octane ran 10.30's @3200 lbs with a c4 shifting/trapping at 7000

never did get to spray it:(
 

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Discussion Starter · #8 ·
last windsor i ran was very similar................383 with flatops, exact same heads, 268/276 roller cam, super victor with a 950 carb on 93 octane ran 10.30's @3200 lbs with a c4 shifting/trapping at 7000

never did get to spray it:(
How much timing where you running w/the high ports?
 

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Discussion Starter · #10 ·
If i remember correctly 36-38 degrees.........
Thats where I was at. Talked to my builder today he said from his experience the high ports like 28-30. Which I didn't even try that little amount of timing..

Wondering if there is a valve spring problem? I paid him to install full new set of valves and check/replace springs if needed. He said the ones where alright but dont know how much seat/open pressure they had..
 

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Thats where I was at. Talked to my builder today he said from his experience the high ports like 28-30. Which I didn't even try that little amount of timing..

Wondering if there is a valve spring problem? I paid him to install full new set of valves and check/replace springs if needed. He said the ones where alright but dont know how much seat/open pressure they had..
I had 225-230 on the seat, 600 open.............still running these same springs on my bluethunder BB heads as we speak...........just checked them 25 passes ago...............think they have 250 plus passes on them now:cool:

K-motion 1150 i think..........ill double check
 

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I wouldn't even touch parts or consider the idea until we get some data out of the engine. When you have some data lets go foward. Until then we could all geuss till we are blue in the face and be dead wrong.
 

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Could be the valve springs....having ones too weak could 'stop' the motor at a certain RPM.So could the intake but you said it came off a similar motor that turned 8000+ than I wouldnt change that yet.

I would check the springs out first, and then if they are good than get that advance outta the cam and see what happends. Taking it out may make it run better NA but not as well on the squeeze.
 

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Discussion Starter · #14 ·
Could be the valve springs....having ones too weak could 'stop' the motor at a certain RPM.So could the intake but you said it came off a similar motor that turned 8000+ than I wouldnt change that yet.

I would check the springs out first, and then if they are good than get that advance outta the cam and see what happends. Taking it out may make it run better NA but not as well on the squeeze.
Springs where checked when the heads where gone through..? I have also been told that springs can sometimes play weird tricks on you..? It pulls hard past 7,300 on little spray so wouldn't think it was the springs..?

Going on the dyno tomorrow and plan on getting numbers before messing with the cam. Then going to pull the advance out of the cam and find out what happens. I would think pulling the advance out would make it run better on nitrous. I will have some info tomorrow and let you all know what we find. If have no luck going to pull it down and start checking springs again, heads, intake,...ect. for problems.

Thanks for all the help and ideas!
 

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I am a little confused.
You advanced the cam which will normally lower the peak torque rpm. Then you put a 2" spacer under the carb which will increase the plentum which normally will raise the torque band up.
Not sure what you were looking to do and don't want to second guess you, so help me understand.
Also with 14:1 and that camthe compression should not be a problem so I would degree the cam back per the cam card and go from there.
If you do move the cam just as a point of reference do a cranking compression before and after.
By the way what fuel are you running w/o spray?
 

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Discussion Starter · #17 ·
I am a little confused.
You advanced the cam which will normally lower the peak torque rpm. Then you put a 2" spacer under the carb which will increase the plentum which normally will raise the torque band up.
Not sure what you were looking to do and don't want to second guess you, so help me understand.
Also with 14:1 and that camthe compression should not be a problem so I would degree the cam back per the cam card and go from there.
If you do move the cam just as a point of reference do a cranking compression before and after.
By the way what fuel are you running w/o spray?
Exactly what I told the engine builder. Doesn't make sense to me why he advanced the cam. This is why I feel the problem is in the cam. Second guess me, thats how problems get fixed. I wont take it personal. Cold cranking pressure is 210 on 7 of them and 230 on 1. After I back the cam up I will let you know the results. I have been running sunoco 114.
 

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Discussion Starter · #18 ·
Engine made 382hp when we pulled it on the dyno and after a few changes it made 392hp. Engine started to build hp at 5,600 and leveled off at 6,300 and started to fall off at 7,000. For shits and giggles we pulled the timing cover off and the cam was straight up..? We retarted the camshaft 4deg. and made another pull. It made EXACTLY the same HP and TQ. but power fell off sooner. Something is VERY messed up in valve train/camshaft ect. Will be calling engine guy tomorrow and give him a chance to make it right..
 
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