Just aint right

[Heavy Evy]

I ran my truck with the new motor at the track 2 weeks ago and boy what a waste of gas. I ran faster last year before all the upgrades and goodies. So whats the prob? I Have no idea (well actully I do I just want some second opions) Heres my set up. 383 stroker 40. over 10 to 1 pistons eagle crank comp 274 extreme energy cam fuelie 1.60 2.02 heads with comp valve springs guides etc roller rockers edelbrock perforemer intake 650 edelbrock carb hedmen headers flowmaster 2 and 1/2 exhaust. Th350 with 2300 stall. Dana 60 with 3.54 gears. Here is my times. 1st run .232 r/t 2.7 60 foot 17.7 1/4 mile. 2nd run .176 r/t 2.7 60 foot 17.6 1/4mile. I killed the other guys off the line but about 1/4 track just couldnt pick up speed fast enough. I think its a gearing problem maybe need to put my 4.10's back in.

[joeys66pickup]

whats with the 2.7 60' footers?....wow i dont think i have ever seen a 17.7 in the 1/4 before, it has to be something Are you sure everything feels ok and its not nosing over and choking or something

[mongoose]

i think i can run a 2.7 60 foot.. hahaha

try the bigger gears... the rest of the combo seems looks to match up pretty well. i'd change the carb and intake of i were to change anything in the motor.

[Jim_PA]

Sounds to me like it's way out of tune. Carb, timing, everything.

[joeys66pickup]

wait...is there something your not telling us?(like the old time was hooking and now your frying the tires the whole track or something)

[Marv D]

What kind of fuel you running. With "10:1" pistons and little 64cc fuelie heads I bet your detonating the CRAP out of things.
What is the cc of the valve reliefs (I'm assuming these are flat top pistons), and what is the deck clearance?

If you zero decked, and have the normal 3-4 cc of valve reliefs,, you have 11.2:1 compression and you BETTER be running a fuel with a motor octane of at least 100 or better,,, or your detonating under heavy load and that may not be all the problem, but it would be a place to start.
You definately have traction issues and need more carb, but I would like to hear the rest of the motor combination.

[Super73]

My first question is going to be what tire are you running?

Next is what was the 1/8 mile ET?

How about mph for both 1/8 and 1/4?


My next question is in reference to you comment "I killed the other guys off the line" You sure you were not killed off the line by the other guy? I have also cut a 60' time similar to that when I was in my 4cyl S10 with a 5 speed. Like a 2.6-2.7 and ran a mid 17 at 77mph

[Heavy Evy]

My 1/4 mile time last year was 16.7 and 16.8 with 31.10/50 tires at 87 or 83 mph(cant remember lost my papers). My 1/8 mile times 2 weeks ago are 11.3 and 11.4 at 63 mph. The other guy's 60' times are 2.8 and 2.9. My current tire size is 285/60/16
Im running 91 pump gas and just set the timing to 25 it was at 16. Might i ad this is a 3/4 ton truck that weighs 5000 lbs with me in it. I just want to get down to the 15's/14's and I'll be happy

[mongoose]

25?

umm total? or initial? that's A LOT of initial timing.. so much as i'd be surprised it if started.

set your total timing to 36.. better yet.. get someone with a curving machine to set it up.. set it at like 10 initial, then dump in 26 more buy 2800..

[Marv D]

Originally Posted by mongoose

25?

umm total? or initial? that's A LOT of initial timing.. so much as i'd be surprised it if started.

set your total timing to 36.. better yet.. get someone with a curving machine to set it up.. set it at like 10 initial, then dump in 26 more buy 2800..

Agreed 100%,, either way something is crazy there. If that 26 is total,, its about 10° short, if thats initial and your distributor is adding a normal 24,, your going to rattle that poor thing to death.

When I first built my 66 it was doing 2.3 and 2.6 sixty's with a nitrous boosted 355. I was launching on the hose with a set of a MickyThompson sportsman tires (not Sportsman Pro,, the hard as nails Sportsmans), 5.43 gears footbraking a TH350 with Midwest 4800 stall. The motor would zing to 7600, I'd shift 1-2, and the tire smoke boil and sloooooowly I'd roll out of the beams towards the 60' cone. A hard, tire spinning launch is not accelerating the truck forward. You might revisit your launch technique and tune up.
Most vehicles will accelerate 23-25mph from the 1/8th to the 1/4. I didn't see your new 1/4 MPH, but is sounds like you made some small changes and MPH is pretty much the same as before. If that's true,, you need to look at the combination. MPH is your indicvator of horsepower. If that stayed the same, you made no improvment. Thing to ask yourself is what's not right in this combination.

There are some pretty darn sharp guys here. You list every detail about the motor, gearing, tire, chassis, tune and launch technique and I bet there is maybe a half a second or more that can be tuned out of the driver, launch technique, shift point, launch rpm, and such without spending a penny.

[fryco]

my 2cents is your cam timing is incorret (did you degree your cam????) and, or ignition timing is off maybe mechanical advance weights stuck?? wrong springs or weights?

its almost always the little things...

[85sqbdy]

I think you answered part of the problem yourself. definitely go back with the 4.10 gears. You have decreased the tire diameter by 1.6 inches, but at the same time put a highway gear in it. With that much weight, you already know you need to seriously multiply the torque just to get it moving. Also, I agree about the timing.

[Heavy Evy]

Originally Posted by Marv D

Agreed 100%,, either way something is crazy there. If that 26 is total,, its about 10° short, if thats initial and your distributor is adding a normal 24,, your going to rattle that poor thing to death.

When I first built my 66 it was doing 2.3 and 2.6 sixty's with a nitrous boosted 355. I was launching on the hose with a set of a MickyThompson sportsman tires (not Sportsman Pro,, the hard as nails Sportsmans), 5.43 gears footbraking a TH350 with Midwest 4800 stall. The motor would zing to 7600, I'd shift 1-2, and the tire smoke boil and sloooooowly I'd roll out of the beams towards the 60' cone. A hard, tire spinning launch is not accelerating the truck forward. You might revisit your launch technique and tune up.
Most vehicles will accelerate 23-25mph from the 1/8th to the 1/4. I didn't see your new 1/4 MPH, but is sounds like you made some small changes and MPH is pretty much the same as before. If that's true,, you need to look at the combination. MPH is your indicvator of horsepower. If that stayed the same, you made no improvment. Thing to ask yourself is what's not right in this combination.

There are some pretty darn sharp guys here. You list every detail about the motor, gearing, tire, chassis, tune and launch technique and I bet there is maybe a half a second or more that can be tuned out of the driver, launch technique, shift point, launch rpm, and such without spending a penny.

I know theres some sharp fella's on here Thats why im on here to get help with my old rusty piece of dirt from other rusty piece of dirt owners haha. I have never heard of a curving machine before but id like to look into it. Im sure the the timing is a problem, after I reset and drove home it would pop at higher rpms maybe detnating? I haven't done a compression a test to see what excatly my compression ratio is. I plan on doing this at work tomorrow

[Marv D]

A compresion test will tell you a lot about the health of the engine, but it won't tell you what the static compression ratio is. Too many variables to use that as a gauge. True compression can only be calculated from carefull measurements of the engine before assembly. But,, we can make some intelligent assumptions if you'll offer what you do know about the motor. Flat tops? with single or double 'eyebrow' type valve reliefs? Was the block decked, was the heads milled, did use use a standard composit head gasket, or a steel shim gasket? you said you have 'fullie' heads, which casting #.? Most were 64cc, but some of the early 327 camelhump heads started lige as 62cc, do some flat miling over the uears and they couple easily be down to 60cc,, compression soars. I am more suspect of the little 650 Edelbrock carb. They are calibrated as a economy carb not a performance carb. So lean at WOT, a timing curve that is questionable,, I still think there is a lot to be found in the tuneup even before you go back to the deeper gears

[Heavy Evy]

Originally Posted by Marv D

A compresion test will tell you a lot about the health of the engine, but it won't tell you what the static compression ratio is. Too many variables to use that as a gauge. True compression can only be calculated from carefull measurements of the engine before assembly. But,, we can make some intelligent assumptions if you'll offer what you do know about the motor. Flat tops? with single or double 'eyebrow' type valve reliefs? Was the block decked, was the heads milled, did use use a standard composit head gasket, or a steel shim gasket? you said you have 'fullie' heads, which casting #.? Most were 64cc, but some of the early 327 camelhump heads started lige as 62cc, do some flat miling over the uears and they couple easily be down to 60cc,, compression soars. I am more suspect of the little 650 Edelbrock carb. They are calibrated as a economy carb not a performance carb. So lean at WOT, a timing curve that is questionable,, I still think there is a lot to be found in the tuneup even before you go back to the deeper gears

The 650 will go as soon as I rebuild my 750 double pump holly. Yes the pistons are flat tops with the single eyebrow valve reliefs and yes to the block being decked and honed and there just standard composit head gaskets no steel shim in between. I still think there is timing issues still and I want to change my wires and plugs plus this is just a stock hei set up maybe I should upgrade? I'll have to check out the heads to get the casting numbers If I remember correctly there either 66 or 67 327 but im not sure

[Marv D]

OK,, I see a issue here given the info. And something you better be VERY cautious of.
First, let's assume you have the larger of the two chambers. Could be the 62, but let's assume there 64cc. Most single valve relief flat tops are only 3-4cc's. Of you decked the blcok,, let's assume just a 0.010 cut to flatten things out, not a zero decked motor.
So:
3.75" sytroke, 4.040" bore
64cc chambers
0.040" thick composit head gasket, at 4.2" diameter bore.
4cc's for valve reliefs
a 0.015" dck clearance.

Your static compression is 10.9:1

If those are the early 327 heads with 62cc's or if they were milled at all,, your over 11:1 compression. You MUST have the timing right and MUST still run a fuel with AT LEAST 95 motor octane IMO,, not R+M/2,, a REAL 95 'MOTOR' octane. VP-red comes to mind.

Here is a list of some of the more common race fuels and their 'real' octane numbers.

http://www.small-block-chevy.com/www/FUELS.pdf

That 274XE may have enough of a late intake closing to help bleed off a little low speed cylinder pressure. But when you get into the rpm range of the cam,, she is going to detonate BIG TIME.

Not sure what pistons you used, but want to see what happens when you detonate a motor built with hypereutectic pistons???? This is what we saw when we pulled the head off my buddy's 406. Piston turned back to sand at the bottom of the oil pan.



proceed cautiously with that timing....

[Heavy Evy]

Point taken and noted. I don't want to rebuild this sucker again. What do you think I should be run the timing at? I checked my plugs yesterday and they have a white/gray coating indicating Iam running lean.

[Marv D]

With that much compression on the street, and the quality of pump gas today,, I'd very VERY conservative. 10 initial, 30-32 total, and have the curve set up for total up more like 3600,, almost no vacuum a dvance,, or at least limit it to no more than 40 total with vacuum in the lower rpm's

That's what 'I' would do,, but that's just me.

First thing you need to do is verify the timing tab and the crank / #1 piston match for TDC. You would be very surprised how far off all the stupid little chrome timing pointers can be.

[Super73]

Originally Posted by Heavy Evy

I checked my plugs yesterday and they have a white/gray coating indicating Iam running lean.

What is your method to checking a plug? There is a big reason I ask..
How many miles were on the plug you checked?
Did you cut the threads off and look deeper in to it?

Most people will pull a plug after driving it around ect. That tells you nothing about what it going on at WOT. You need to read the plugs specifically for WOT. Best thing to do for that, get the vehicle to running temp. Shut it off and put a brand new set up plugs in it. Have it towed through the staging lanes. Fire it it to do you burn out, stage, let it rip and at the end of the 1/4, shut it off right away!! Coast off the track and all the way back if you can or hve your tow vehicle tow you back. Then pull the plugs and cut the threads off and look at them.

Here is a great write up and the second link is a pictorial.
http://www.dragstuff.com/techarticle...ark-plugs.html
http://www.dragstuff.com/techarticle...-pictures.html

[Heavy Evy]

Originally Posted by Marv D

With that much compression on the street, and the quality of pump gas today,, I'd very VERY conservative. 10 initial, 30-32 total, and have the curve set up for total up more like 3600,, almost no vacuum a dvance,, or at least limit it to no more than 40 total with vacuum in the lower rpm's

That's what 'I' would do,, but that's just me.

First thing you need to do is verify the timing tab and the crank / #1 piston match for TDC. You would be very surprised how far off all the stupid little chrome timing pointers can be.

For the intitial timing it would be 10 on the timing tab?

[WyoGMC]

I don't have any ideas motor wise. Sounds like you have some advise on that. For me I would put in the lower gears. And those that say the 2.7 60' is bad. One thing he did not mention is where he is racing. DA was probably around 7k+. To run a 14 at altitude is impressive to me in a truck. My old truck ran a best of 14.0 @ 100 with a 2.2 60' (Dodge Ram SRT-10 Quad Cab). Down at sea level (Sacramento) my truck run 12.9 @ 109, 1.9 60'.

[Heavy Evy]

I set my initial timing at 10 and and have 95 octane its running alot better no more poping at higher at rpms. I have not messed with springs and stuff in the dist for the timing curve yet. I'm racing here in Utah where we are above sea level but im not sure how high (cant remember at the moment). I'm not sure if I want to throw the 410's back in yet because I drive this truck on the street alot and prefer the lower rpms on the freeway but I haven't made up my mind yet. Thanks for all the help and constructive criticism.

[Marv D]

Just took a look at google earth. SaltLake is 4300 feet of elevation out near the airport and upwards of 4800 up in the foothills to the east. Given summer months, I'd probably expect density altitude to be well into the 5000' range if not 6000-7000 like WyoGMC brought up.
Bring that thing to sea level and it is almost a full second quicker.

High altitude fuels are formulated a little differently than fuel they deliver here in Phx and 1200' of elevation. You should be able to get away with a little more timing advance (by 'little' I mean 2-5 degrees) but you need to make sure what you have first. Disconnect and plug the vacuum advance line dron the carb. Set timing to 10 degrees on the timing tab and shut the motor off. If you have the typical 8-3/8" balancer, measure 2-1/4" CLOCKWISE from teh zero mark and put a magic marker line on the balancer. This mark will be 'roughly' 32 degrees advanced for a 8" balancer. Your going to have to be creative and make sure what balancer you have for this to work. But it is simple geometry. Diameter times pi is circumference. Total circumference is 360 degrees. So divide circumference by 360, then that # times 32 will tell you haw far to measure for 32 degrees. Pretty simple eh!

After marking the balancer for 32 degrees, connect your timing light, start the motor and snap the throttle up to achive 3500rpm or more. You don't have to hold it there, just achieve 3500= for a 1/2 a second and it will toss the distributor weights to full travel so yu can see how close to your mark on the balancer is. The 32° mark you put on your balancer should line up with the TDC or ZERO mark on the timing tab. THAT is your total timing.

If you have 10 at idle, you know your mechanical advance adds 22° Now you can re-connect the vacuum lint to the advance and see how much that adds. That is a fixed amount. Should be only 8 to 16 degrees depending on model and if it is operating properly, if it has been modified,, etc. Vacuum advance is not really important to ET. When at WTO it is not adding anything, it only adds timing at cruise and idle. So don't get too crazy over that just yet.

So let us know what you end up with from the test here. Once we know yor total, and what that results in initial, we can offer some suggestions if it is a problem, where to start or go next.

[Beatcoaster]

650cfm carb for a 383 is a little low too isn't it?...I have to think at the higher rpm's that 650 isn't flowing enough for you.

[blowncrazyer]

4.10 and throw that carb away