Reddeath210

iTrader: (1)

Just got my car back from the shop. They tuned and dynoed it, and according to the sheet, the car is at 250 RWHP, and about 300 ft's of toruqe. To me it sounds way lower than it should be.

Its has the following
383 eagle stroker kit
CompCam XE294H-10
Edelbrock E-tec 210 heads
Comp Cams roller rockers
Edelbrock RPM performer intake
Holley 670 street avenger
Brand new torque converter with 2600-2800 stall speed.

250 just seems very low to me, I was expecting minimum of 300-350

is there something I am missing?

Tibo

iTrader: (15)

Something(s) is way off. To really help you need to give much more info.
Did you build the engine or did a "shop?"
Is the engine brand new or purchased used from someone unknown?
If it is a new engine:
Was the block Zero decked?
Do you know what the ring gap was set at? could be way too big/small
Have done a leak down test to see if you have one or multiple cylinders sealing?
Could be valves not sealing against the seat, bent valve, Warped cylinder head, warped deck surface, piston rings that never sealed, etc,.
Is the valve lash correct? Meaning none of the pushrods are loose etc.
Are all the lifters good?
Do you have proper length pushrods? Too short and you could be loosing lift.
Im just spit balling but at a minimum start with a leakdown test on all cylinders.

DeltaElite121

Which kit did you use. Need more info. Something is not right somewhere. What was the timing set at?

I am also curious at your build and who did it. Sounds to me like something wasn't put in correctly somewhere. Any stuttering or audible noise? Hesitation?

Tibo

iTrader: (15)

To play off that, If the spark plugs are all out does the crank turn by hand with a breaker bar "fairly" easily or is difficult? What fuel was used? 87/89/90/91/92/93?

Reddeath210

iTrader: (1)

Its using 93, bought the engine from a member here Killert He built the engine
It is the engine in his picture
https://www.thirdgen.org/forums/memb...mour-shot.html

sofakingdom

iTrader: (1)

It runs out of power at a WAY WAY WAY WAY WAY low RPM. (which is more important than the absolute power #s... the curve tells more than the #s at the peaks)

Looks kinda like not enough valve spring for the cam.

Not enough carb, either; but you're not really getting close to that particular limit just yet.

Reddeath210

iTrader: (1)

So you think a heavier spring, and a different carb?

DeltaElite121

You should start pulling hard with that cam where you're dropping off. Thats the first thing I noticed as well. I'd recommend a good manual secondaries 750.

Reddeath210

iTrader: (1)

Can u explain alittle bit more, sorry I am still new to alot of stuff

Orr89RocZ

iTrader: (20)

Which etecs you buy? That will tell what spring is in it. Motor should run to 6500

Tibo

iTrader: (15)

So are you using the 274 or 294 cam?

cuisinartvette

x2

http://www.edelbrock.com/automotive/...eries-sb.shtml

Id put an AED 750 or something similar on it get the springs right then check everything with A/F guage.
A carbed car can "feel fine" and be so far off the map its not funny

Getting the right curve on the distributor can make a NIGHT and day difference find someone with an old Sun machine to set it up.
Tried every combo with my msd kit it was flat.....got it to the right guy who made his own stops bushings literally felt like 100hp gain it was THAT major.

The power is there just got a few things going on. Keep at it, should be a hard running car when right.

skinny z

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skinny z

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Reddeath210

iTrader: (1)

He told me the 294

skinny z

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Reddeath210

iTrader: (1)

I guess that's where a lot of issues come in for me, since the majority of the internal stuff, such as deck height, Compression ratio, and cc combustion ect.. I don't know because I didn't build the engine. Most of the information i was given about the engine was just basic stuff. I don't know what kind of power it made before, but even on a non flattering dyno id figure at least 300rwhp

big hammer

something is happening at 4200 rpm. both TQ and HP take a **** right there. could be so many things, from fuel, spark, bad converter, etc.

skinny z

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skinny z

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Fast355

iTrader: (2)

The engine is never going to make good power from manifolds and stock Y-pipe. What is the exhaust setup?

Reddeath210

iTrader: (1)

Full Catback dynomax exhaust. Edelbrock RPM performer manifold 3500-5500 RPM range

camarito

torque drops too quick, looks like your transmission is slipping

Drac0nic

The RPM isn't a bad intake, but do you mean that you're running only a catback exhaust and manifolds? If so you're choking that engine quite a bit. That's a ton of engine, and the stock exhaust system is considered a "first to go" item on these cars.

Otherwise I would likely look into (in this order) WOT vacuum at higher RPM (make sure the secondaries are opening), fueling, ignition curve, trans (if the MPH is off for the RPM when wide open but usually you can feel it slipping) compression, cam timing (if compression is low, but even.)

The reasons are as follows:

1)If you have the secondaries not opening you'll choke the engine out for air. You shouldn't be at that carb's limit with 250hp at the wheels by any means. If I remember correctly Street Avengers are considered an "under rated" carb in terms of air flow.

2/3)Fueling and ignition are somewhat together. Make sure you're not leaning the engine out. You should be all in for advance way before 4200 RPM, so get a timing tape or a dial back light (I prefer tape actually, less complexity overall) and ensure that you're actually getting timing to come all in and stay in at higher RPMs. You can use the tape, the light and an external tach to verify that you've got enough timing. Pull plugs and make sure that they look even and aren't getting melted or caked in unburnt fuel. Not as good as a wide band (worth $200 IMO) but definitely a sanity check. If you pull plugs, you may want to check gaps too. This seems to be an issue on power adder engines, not N/A ones.

4)Trans is pretty self explanatory. You should feel it slipping if it is. If it's a 700R4 third or fourth tended to be where I'd have problems.

5/6)Low cam timing can cause pressure issues. It still doesn't explain the odd curve.

Reddeath210

iTrader: (1)

Some more information on the car, I forgot to add that it DOES have headman headers on the car aswell. The trans does not fee like it slipping, it does shift pretty hard, but its suppose to have a B&M shiftkit in it, which I was told it should feel that way. It also has a brand new torque converter in it, with an RPM range of 2600-2800. Another note is I just paid roughly 3 grand, for the car to be tuned, and made running. We where having some fuel line issues and spark issues. They replaced the HEI distributor, with a MSD kit. Which has a smaller distributor, an external ignition coil, and an MSD computer to go with it. I am pretty broke currently, I think the work they did was good, everything looks great. I am just very disappointed on the RWHP. They also told me the engine is making roughly 375HP to the flexplate, but they didn't dyno the engine b4 hand, since me and my father installed the engine

Reddeath210

iTrader: (1)

MORE INFO, the headers are off a different engine and I DIDNOT match them to the E-210's. I don't know if your suppose to or not. The headers came off my old 383, that had Pro comp heads on there, I don't know the specs.

Tibo

iTrader: (15)

I think it would work best if we stopped playing the guessing game until you found out what cam and valve springs you have and do the compression checks.

DeltaElite121

Not talking down to you, but this is a perfect example of why your first build should be NEW and not someone else's used setup.. because if you have headaches you have no effective way of tracing your steps back. If you really want to fix this you're most likely going to need to start pulling thing back apart methodically in order to figure things out.

skinny z

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skinny z

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Night rider327

iTrader: (13)

Find a new shop. They ripped you off on the MSD parts and tuning. They up sold you parts you didn't need. The MSD system does work but on a mild engine you will not gain any power from it over a good working std HEI dist.
The benefits comes with higher HP, higher rpm engines, with big cam, etc. You will see a noteable diff between a stock ign. system and like the MSD system on a 7,000 RPM 500 HP small block.

250 RWHP does not equal 375 flywheel HP. You loose 15-20% through drivetrain. 375 - 20% = 300 rwhp.

As mentioned already, you have a strange dip in the power curve. My 1st guess is weak valve springs but could be a number of other things as well

InfernalVortex

iTrader: (4)

Yeah Im not sure how you go from 250 whp to 375 fwhp...

But I dont trust chassis dynos anyway. I'd much rather go to a drag strip, weigh the car, and see what it traps.

But since they tuned it, it's likely jetted and timed somewhat accurately, so I would start digging into compression numbers and potential valve spring concerns. You're gonna have to get your hands a little dirty but you'll learn a lot.

I'd suggest after you get your compression numbers to pull one of the valve springs adn run it by a machine shop and see if they can tell you the pressures and coil bind points and whatnot. I think they're able to do that sort of thing at most speed shops.

Reddeath210

iTrader: (1)

=====Update=====
So I have been asking around and talking to people about the car, and doing research during the winter (since I do not own a garage, i can put the car in). After talking to some people, they said the camshaft would have to be changed to match all the stuff in the car.

The gentleman i spoke to, said that the camshaft is to big, and is being starved by my Carb, possibly my intake, my torque converter, and the fact that I "think" the car has shortie headers. He says for my application it would be best to swap the camshaft. Since the camshaft doesn't produce a lot of vacuum for brakes.

So that leaves me with 2 options. Either replace the parts that where specified, and get parts that flow with the camshaft better, or take the camshaft out, and replace that with a smaller camshaft.

My only concern with changing the camshaft, is that changes the lower half of the engine quite a bit, and since i know everything ran great b4, wouldnt it be smarter to change the parts to match the camshaft currently. Than to resolve the brake issue just use a hydraulic brake system, instead of vacuum.

I am at a loss still currently, I plan on doing a compression check on the engine as soon as possible. I am really also trying to avoid taking the whole engine out and rebuilding it from scratch.

Another thing through out the winter I would go out, and start the car, even take it around the block to get everything moving. I noticed some the electronics progressively stopped working. The interior lights no longer come on and the headlights no longer move at all. I dont know if that has to do with the engine, and the install, but everything worked fine b4 that.

This a video of the car running recently
https://www.youtube.com/watch?v=BUSZ...ature=youtu.be
Car tends to stall a lot until its up to about 200.

Thanks for reading

camarito

Sounds like it's starving for timing

Reddeath210

iTrader: (1)

So what does that mean?

skinny z

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Night rider327

iTrader: (13)

Look it's not the mis match of the intake, carb, headers, etc.

The thing is running out of RPM way too soon for a cam that big.

Here is a few things I think it is....

Valve springs.... This is where I would place my bet. Valve springs way too weak for that cam.

Not enough timing. Set timing to 18* before TDC at idle w/o vac advance hooked up.

Not enough compression... Get a compression gauge on it. They can be had for $20 at any auto part store and might take you an hour to test all 8 cylinders.

The 210cc port is big. My performer RPM intake just barely sealed to my 200cc brodix heads. You may not have a full seal between intake and head ports.

Not enough fuel... No this does not mean not enough carb, this means not enough fuel volume/supply. Your pump may not be high volume enough. I would want atleast a 130 GPH pump with that engine. Heck I use 160 GPH pump on mine with a little less cam than you have.

If that is the XE294H-10 cam, it is a beast.
250/256@.050, .519"/.523" lift, 110 LSA

Your carb is a little small for that, so is the converter, but headers and intake aint really a prob..

The carb and converter is NOT killing off that much power or RPM.

The fact that the power is dropping off at the RPM it is, is what you need to look at/think about. Your not even pulling to 5500 RPM! You should have another 1,000 RPM in there atleast.

With a 355, 249/252 @.050", .570"/.579" lift cam, RPM intake, Brodix IK 200 heads, etc. I make peak power at 6800 RPM and shift at 7000-7200 rpm

InfernalVortex

iTrader: (4)

Agreed on all counts here... he has a big cam and big heads. The Performer RPM may be slightly small, but those can support up to 500hp and 6000 RPM without a problem. A single plane might be better, but even so, the Performer RPM can hold it's own vs many single planes.

Race cars with tiny tiny restrictors still make tons of power. Same with carbs. You restrict the intake, and the engine just pulls more vacuum to compensate. It's not like you hit a wall and power falls off a cliff. It's a gradual thing that gets worse with the restriction, but it's not going to turn a 400hp car into a 200hp car. Same with exhaust. You lose high RPM efficiency, you dont just hit a wall.

mcbchild

iTrader: (1)

Here is my 2 cents worth that might give some insights. With that cam, you are looking at around a 3000 stall, 3:42 and numerically higher numbers, min. 10 to 1 compression (Make sure compression test is at least 175 psi or higher), a single plane intake would be preferred, but the RPM in my opinion won't kill you too bad, a carb min 650 cfm DP or 750 VS, but the 670 Avenger shouldn't hurt you too much either. some type of hi-flow fuel pump and if reg is used, keep the fuel pressure around 6-6.5 or 7 psi max. If you are still using the MSD ignition, trade it for a decent Performance HEI dizzy, this way you eliminate a possible fault between the dizzy, external coil and MSD CDI setup, too many places between connection that could be faulty , if you are still using these items. Exhaust seems pretty decent. If any thing was changed with the carb you have now, put it back to factory specs. But to get started, run the compression test and have the valve springs checked is where I would begin.

Like i said, just my 2 cents.

25thannivZ28

I had similar issue with mine, my 350 made 308/312. I put my 406 (with same exhaust system) in and got 308/308 running 12.9 @108.. I put my 4" exhaust on and replaced my fuel pump and ran an 11.9 @ 117. Could have been better, but I toasted 3rd gear on that run. I've since gotten a new transmission with a 3500 stall, where before I had 2500. I don't have dyno #'s yet, I plan on spring sometime.

So my issue was solved with replacing a bad fuel pump that couldnt keep up and freeing up the exhaust.

Hope that helps

Ozz1967

iTrader: (4)

Do a compression test, this will tell you many things and should be done first.

Come back and tell us the numbers!

My 350 has 260rwhp because I didn't get it decked, should be around 300. That was my mistake.

Please, don't listen to people you meet. We are a resource and genuinely care about you getting the best out of your car. We have all been through this. Learn from our mistakes and please don't duplicate them.

Tibo

iTrader: (15)

Haha saw the clips and love your license plate! My camaro started out as your identical twin before I painted it. Rare to see a camaro that color in as good of shape. What cam is in the 400?

2005Impalla

I don't think a compression check will tell us much. Un even compression, bad valve sealing, rings, or low compression would not cause this. It looks like a fuel problem. This might be were your secondary's are opening. Your jetting could be off. You should be able to feel this drop driving the car so I would take it for a run and if you can feel it drop off in power around 4K then I would change swap the spring out for the sec and run it again and see it the power drops off at a different RPM. Your carburetor came with 2 springs a softer one and a stiffer one, Try them both and see if the drop shifts RPMs. Could also be starving at high RPM so I would see if raising the float level changes things.

Night rider327

iTrader: (13)

Sorry but I strongly disagree with you... Sticking a big 250* @.050" cam in a low compression engine will 100% cause this.

The OP is using a really big cam. In fact that cam really needs a min of 10.5:1 compression and 11.0:1 would be about perfect.

So putting that cam in a 8.5, 9.5:1 engine aint gonna do very well.

A compression test will show the cylinder pressure and if it's like 100-130 psi we will know his staic compression is too low. For good performance you need to see around 175 min psi with 190-200 psi being better.

ddeennis

Heck I would like to see a cranking compression check , not sure why the delay of doing it, unless the OP is really totally broke and can't afford it, maybe don't know how. just go out and buy the gauge, pull one spark plug, easiest to get to, pull the hot wire from the dist. and get in the car , floor the gas pedal and and cranking it for about a 4 second count and get out and look at the gauge and post up the number, simple.


Even a sbc with 10.2 to 1 compression with a 234/244 @ .050" cam has 160 psi, 11.8 to 1 bbc with a 262/273@ .050" cam has 150 psi, 233/239 @ .050" cam and 10.2 to 1 has 180 psi.

if the cranking compression is anything below 150 psi, the compression is way to low. Heck even a 7.7 to 1 engine with a tiny 216@ .050" cam has 150 psi, bump that cam up to 228@.050" and it becomes 135psi and a real dog.

My 25 plus years of building engines you don't want to mess with anything below 150 psi cranking compression, static compression way to low for given cam size, it's best to be around 175-185. we are talking compression ratio's match to a given cam size. when a cam manufacture recommends a certain static compression range for the given cam

I'm not talking about a stock engines/ cam profiles looking for health problems

I am talking street cars to tolerate 87 octane fuel. Not race engines with 275 psi 14.5 to 1 compression, solid roller engines.

the target range is 150 psi to about 185 psi to tolerate 87 octane fuel, sure 200 can be done but want to keep it simple, if your below the 150 target, then the cam needs to be smaller, you could cheat some by advancing the cam 2 more degrees maybe more, but you really would need to drop down in cam size to get a closing point that will allow a higher dynamic compression ratio to boost maybe say 140 psi cranking compression to 160 psi, you would still be on the low end of the cranking compression, but not all is lost. I have built plenty of 12 second and 11 second engines on 87 octane only boosting 160 psi cranking compression.

Never the less, go buy or borrow a gauge and do it. at least see where you stand, this would determine the next step if the engine needs to come apart to raise compression or buy a smaller cam.

valve springs at this point don't mean nothing, good or bad, if you don't have enough compression for the cam, the engine gets a major change.

Post up when you at least have a result of one hole, if you truly want some help. so many folks posted up you just keep ignoring what really needs to be done to be helped. Specially when you don't have good specs of what really is in the engine. so we have to kinda go old school and get results from cranking compression to see even if your in the ball park of moving forward with other changes make things better.

25thannivZ28

Thank you, I have Howards cam p.n. 180345-10. Doesn't provide much vacuum for brakes. 6# maybe, had to buy a vacuum pump. http://m.summitracing.com/parts/hrs-180345-10

25thannivZ28

I was made aware of my fuel pump issue when the speed shop did the 1 - gallon bucket test. They had put power to the pump and sucked gas from one bucket to the next. How long the transfer takes gave them the notion that my fuel pump was the weak point. From taking 45 seconds with the tired pump down to 15 seconds I think they said it was with new pump.

My dyno pull also peaked and took a dump at around 4k with the old pump

LsxMatt

iTrader: (4)

Like everyone else has been saying here, DO A COMPRESSION TEST!! I built a 350 a few years ago, it was my first bottom end build. I honed the cylinders, new rings, bearings, cam, heads, the whole 9. Sounded awesome but felt like it had ways less power than it should of had.

First issue was the aftermarket balancer i bought was 8 degrees off. Timing was waaay retarded and after figuring this out with a piston stop, it had much more pull but still not enough. Eventually i did leak down test after around 1000 miles, and all cylinders had 40% leak down and 120psi compression. Should of bored the cylinders. Never had it on the dyno, but with the parts i used it should of made over 350whp. Felt like it had 200whp.

Night rider327

iTrader: (13)

To the OP... Just about all major chain part stores has a loan a tool program.

Pay up front, use tool for up to 30 days, bring tool back, get your money back..

http://www.autozone.com/landing/page...me=loan-a-tool

Here is the compression tester http://www.autozone.com/loan-a-tools...et/424906_0_0/

$40 up front, get full $40 back when you bring tool back to store

2005Impalla

The low compression would cause the motor to suffer more in the bottom end then the midrange. My fathers Chevelle when I was a kid had around 9.5 compression and 244* @0.050 and would pull the front tires off the ground. I have rode in a few street cars with stock low compression 350s with large cams in the 230* range that pulled up to 6,000-6,500 so I am not buying the low compression thing causing the dip. It would suffer more in the low RPM than the RPM were it should be making peak torque at. This is something not keeping up. Its either an ignition problem or a fuel problem. I am betting it is were the secondary's are opening up. Your curve looks a little low on torque too though and am betting the whole thing is out of tune. I do agree though the compression should be around 10:1+ but the heads are 64cc chambers and its an eagle 383 kit, don't know which one but it should be around 9.4-9.9 depending on the kit he used. Even with 9.4 compression that motor should run like hell and have no dip. It should be lacking some power compared to 10+ compression not 50 though and it should be a linear curve tell after peak HP which should be about 2,000 RPM higher. I have seen a lot of motors with less compression than what's recommended and they don't do this.