Is my engine performing as it should??

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crackedback said:
The cam you have is capable of 350HP.

I did a camquest and came up with something around 370hp 420 tq which is still pretty aggressive. Those programs also assume a perfect tune. It was almost spot on with a couple of recent builds compared Dyno numbers.

1.7 rockers are a ***** to use, cause all sorts of problems. Adding lift doesn't equate to making a ton more HP. Sometimes it's negligible. On your style, desired build engine, they flat aren't needed. There are valid reasons to use 1.7 rockers, IMO, none of those are present here.

That engine could run with a 950hp on it. I wouldn't run one with your converter/gears. Some say it's crazy, but, they work. Done it more than once. The carb you are running will make it weeze up top IMO. Driveability will be good, max power won't. SB chryslers tend to love carb.

Good luck with it.
Click to expand...

I've tried a bigger carb before, I borrowed a 750 Demon Double Pumper from a guy at my dads work. I don't know if the carb was just overkill for the current setup, or if it was because the automatic just hates that much fuel down low, but it acted terrible during takeoff. If you hammered the gas from a dead stop, the car would just take off without breaking the tires loose, but If you pressed the gas about a 1/4 of the way, the tires would spin! So I agree about not putting a 950hp on mine :)
 
Johnny,

I just read your post and have a few question and suggestions. First the questions:

1: What part number is that cam and was it degreed when it was installed?
2: Is the compression ratio a true measured ratio including all the variables such as gasket bore/thickness, true head cc, piston depth in the bore, etc? It may be lower than you think.

Next, a couple of suggestions:

1: Close up that plug gap for Pete's sake! Dump the platinum stuff and get some autolite standard style plugs. Leave the plug gap @ .035 or .040 at the most until you get everything else sorted out.

2: How deep are the pistons in the bore? You say the block was decked but by how much? You may be able to use the MP .020 thick head gaskets to bump your compression. Your 60' will improve and the car will feel much "snappier" of the line (assuming you're not already spinning hard).

3: Install the correct valve springs for your cam at the correct installed height and check for coil bind, retainer to guide/seal clearance @ at the lift of any cam you might install.

4. Once you're are sure that your compression is at least 9.5:1, install this cam:
http://www.compcams.com/Cam_Specs/CamDetails.aspx?csid=637&sb=2 It's as big as you will want to go on a daily driver and will just sing on the highway. You will need to bump your gearing up to 3.55 and a 2500 rpm stall would be mandatory. The very tight lobe centers will preserve all important cylinder pressure at low-mid rpm. This cam will have a nice chop at idle but will still be streetable if the aforementioned converter is installed. Forget power brakes though, it ain't happening.

5. Install a quality adjustable valve train with 1.6 ratio rockers from comp or other well known manufacturer. Stay away from the imported stuff.

6. Use a quality converter!!! You won't be happy with the cheap Summit stuff. May I suggest a Dynamic converter by Frank Lupo. Make sure you tell him exactly what your combo is and leave out the inflated computer estimates.

Now, a conclusion:

The above would be a max effort street engine built around your heads and rotating assembly that should top 400 hp without a problem. :-D It just might scare you when it comes on the cam, lol. It won't be cheap but it will take advantage of the heads and not require a complete rotating assembly tear-down to bump your compression. You can forget power brakes and some serious carb and ignition tuning will be mandatory.

What you have now is a mis-match. That cam may have a wide lobe center and when that is combined with the low compression bottom and and ported heads, you have crappy 60' times. There are head porters who can boost your head flow from .200 lift to .600 lift but their work does not come cheap and can run to 1K or more on iron heads. If you can get us some flow numbers, that would be very helpful. For a street engine, it's hard to beat some magnum heads with a a good 5 angle valve job and a pocket port. 1.6 stock rocker ratio is helpful as is the ease of setting up the valvetrain.

As you can see, it's all about how all the parts work together. As far as the present combo stands, it's doing OK for what you got but really could be in the 13's if your compression was higher and magnum heads were used with a quality 2000 rpm converter, and the block were decked down to "0" and .040 gasket used for some quench. That would be the cheapest way to go. As it stands, it's kind of a "band-aid" approach to get you in the 300 hp + range.

I hope this helps.
 
I'll say again. XE268 and Comp 901 springs. Leave everything else alone. Shoudl cost about $400 if that in parts. If you gear up later, so much the better. But you dont have to. And take those dyno sims and use them when you're playing Wii. They are as good as any video game, but if they come out accurate, there is a certain amount of luck associated with their result. They are ALWAYS high.
 
moper said:
I'll say again. XE268 and Comp 901 springs. Leave everything else alone. Shoudl cost about $400 if that in parts. If you gear up later, so much the better. But you dont have to.

Nothing wrong with that suggestion at all but I sure would like to see some more compression. If he can drop on some .020 gaskets and not run into any P to H clearance problems, he may as well do it for the extra 40 bucks. He should probably get some adj. rockers when using the XE cams anyway. IIRC, Comp recommends it on the XE series cams, unless he knows how to measure pushrods for preload.

And take those dyno sims and use them when you're playing Wii. They are as good as any video game, but if they come out accurate, there is a certain amount of luck associated with their result. They are ALWAYS high.
Click to expand...

lol! The good ones have their place, but the free ones are about worthless. Garbage in, garbage out....
 
That cam is really small i'd go bigger,close that spark plug gap to 040,stock converter is hurting you,and more gear like 3.91's would help a lot too..for a really good converter call Lenny at Ultimate for my money he's the best in the bussiness..203-874-2100 tell him Dave from Boston sent ya'...
 
ramcharger said:
Johnny,

I just read your post and have a few question and suggestions. First the questions:

1: What part number is that cam and was it degreed when it was installed?
2: Is the compression ratio a true measured ratio including all the variables such as gasket bore/thickness, true head cc, piston depth in the bore, etc? It may be lower than you think.

Next, a couple of suggestions:

1: Close up that plug gap for Pete's sake! Dump the platinum stuff and get some autolite standard style plugs. Leave the plug gap @ .035 or .040 at the most until you get everything else sorted out.

2: How deep are the pistons in the bore? You say the block was decked but by how much? You may be able to use the MP .020 thick head gaskets to bump your compression. Your 60' will improve and the car will feel much "snappier" of the line (assuming you're not already spinning hard).

3: Install the correct valve springs for your cam at the correct installed height and check for coil bind, retainer to guide/seal clearance @ at the lift of any cam you might install.

4. Once you're are sure that your compression is at least 9.5:1, install this cam:
http://www.compcams.com/Cam_Specs/CamDetails.aspx?csid=637&sb=2 It's as big as you will want to go on a daily driver and will just sing on the highway. You will need to bump your gearing up to 3.55 and a 2500 rpm stall would be mandatory. The very tight lobe centers will preserve all important cylinder pressure at low-mid rpm. This cam will have a nice chop at idle but will still be streetable if the aforementioned converter is installed. Forget power brakes though, it ain't happening.

5. Install a quality adjustable valve train with 1.6 ratio rockers from comp or other well known manufacturer. Stay away from the imported stuff.

6. Use a quality converter!!! You won't be happy with the cheap Summit stuff. May I suggest a Dynamic converter by Frank Lupo. Make sure you tell him exactly what your combo is and leave out the inflated computer estimates.

Now, a conclusion:

The above would be a max effort street engine built around your heads and rotating assembly that should top 400 hp without a problem. :-D It just might scare you when it comes on the cam, lol. It won't be cheap but it will take advantage of the heads and not require a complete rotating assembly tear-down to bump your compression. You can forget power brakes and some serious carb and ignition tuning will be mandatory.

What you have now is a mis-match. That cam may have a wide lobe center and when that is combined with the low compression bottom and and ported heads, you have crappy 60' times. There are head porters who can boost your head flow from .200 lift to .600 lift but their work does not come cheap and can run to 1K or more on iron heads. If you can get us some flow numbers, that would be very helpful. For a street engine, it's hard to beat some magnum heads with a a good 5 angle valve job and a pocket port. 1.6 stock rocker ratio is helpful as is the ease of setting up the valvetrain.

As you can see, it's all about how all the parts work together. As far as the present combo stands, it's doing OK for what you got but really could be in the 13's if your compression was higher and magnum heads were used with a quality 2000 rpm converter, and the block were decked down to "0" and .040 gasket used for some quench. That would be the cheapest way to go. As it stands, it's kind of a "band-aid" approach to get you in the 300 hp + range.

I hope this helps.
Click to expand...

I don't know how much the block was decked, my dad was the one who picked it up, I would ask him, but he's out on business. And the 9.3:1 compression should be exact, it was all measured with water, including adding in the space the gasket took after being smashed down.

The cam is a 268H (not the Xtreme engergy though), and it was not degree'd when installed. It seems like the bottom end is doing fairly well, it could be better, but it will still squeel on the track with caltracs and street tires. The caltracs (traction bars only, is what I have) helped quite a bit if anyone is considering them. It helped the car stop roasting the tires when the throttle was mashed. Now it just squeels a little, fishtails a bit, then goes. Both cams mentioned looked pretty good for the setup, although im not an expert, I still haven't quite figured out the effects of lobe seperation and the intake centerline. But thanks for the advice you all have given.

BTW, just got a pic of the duster in the sig now 8)
 
jonnyboy1617 said:
I don't know how much the block was decked, my dad was the one who picked it up, I would ask him, but he's out on business. And the 9.3:1 compression should be exact, it was all measured with water, including adding in the space the gasket took after being smashed down.

Excellent! That's a great start and gives a great baseline to work with. Your Dad sounds like a great guy to be helping his son on this build. Be sure to thank him. :-D

The cam is a 268H (not the Xtreme engergy though), and it was not degree'd when installed.

That's the High Energy series cam and pretty much the biggest you can get away with a stock valve train, converter and power brakes. If it's squeeling on the track from the get go with Cal-Tracs, it's probably right on anyway and not worth breaking down the entire engine unless you want to install a bigger cam anyhow. The XE series 268 would give you some more power but not enough to warrant a cam change. Oh yeah, like Moper said, change out those valve springs! It can be done with the head on the engine with an air compressor or some guys have even used a rope stuffed in the cylinder. You'll also need the appropriate valve spring compressor which can be made or purchased.

It seems like the bottom end is doing fairly well, it could be better, but it will still squeel on the track with caltracs and street tires. The caltracs (traction bars only, is what I have) helped quite a bit if anyone is considering them. It helped the car stop roasting the tires when the throttle was mashed. Now it just squeels a little, fishtails a bit, then goes. Both cams mentioned looked pretty good for the setup, although im not an expert, I still haven't quite figured out the effects of lobe seperation and the intake centerline. But thanks for the advice you all have given.

If I were you and had limited funds, I would invest in some M/T slicks and SS springs before adding any more power. It just may get you in the 13.9x area. That 60' time is killing you and the fishtailing you mention is a tell tale sign of excessive wheel spin. A spring relocation kit so you can fit some fatter tires wouldn't hurt either. Then, you could just get to the strip, swap out the rear wheel/tire combo and go rip off some 13's. :-D Once you have wheel spin under control you could go with a converter in the 2500 rpm range and then a gear. If you still have wheel spin under control, then think about adding more cam/compression. :)

BTW, just got a pic of the duster in the sig now 8)
Click to expand...

Nice Duster!
 
Since you are in high school and probably have a limited budget, I would suggest leaving the whole shebang pretty much alone and just have fun with it. Cars are a great place to spend your cash but so are girls, and at your age you still get some say in the balance between the two.

Have you actually weighed the car? You might be surprised how heavy a street can can really be.

Are you racing on street tires? If I had a couple hundred bucks burning a hole in my pocket I'd get some track tires. Your 60' times will drop and your street tires will last a LOT longer. You will be a lot more consistent as well.

Next I would play with a 750 carb with controlled secondaries (non-double pumper!!!). A 1" open hole spacer (cheap to try) might help your top end. If so, a bigger carb will certainly help.

A better converter would be next (spend money for a GOOD one), then maybe more cam depending on your gears.
 
He said he's got "fully ported j-heads" ( do they flow 220 or 250 @.450 lift ?). Mis-matched stuff/expectations. Torquey cam, small carb, dual-plane, high-ish ratio gears, stock converter, and drives on the highway daily, and then ya throw in the "stiff springs"(?) on the "fully ported " heads. Leave it alone 'til you decide what kind of driving ( power range) and $$ you want to commit to. Probably run better with stock j's , vacuum 750, and better tires. Then he can start spending the coin to change the power/operating range he's decided on(cam, converter,gears, and his fully ported heads). My 2 cents
 
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