[vinniekq2]

PJ thats a great post.I am getting lazy and should have asked more questions of the OP.If all the details you mentioned are dealt with,then this car should go quite well. Im not a big fan of any really big hydraulic flat tappet cams myself.I figure if you step up to the plate and build some serious power,then I think a camshaft is a good place to pick above average parts.
Again,I forget about blue printing being a standard procedure.90caprice408 we will get you going soon,dont worry.I had a similar problem with a combination before with a 350 with what I thought was going to fly. I just bought a set of heads from Lee Shepard and I had a big solid cam with 5.13 gears.The car was a turd.
Turns out it was a bad converter.After I replaced the converter it came back to life.

[90caprice408]

Originally Posted by painted jester

Timings a good guess if the blue print is right, We are assuming the cam was degreed and checks out right but don't know if its advanced, straight up or retarded, Or if the cam has an advance already in the grind, His gears are small should be at the least 4.11s, we don't know if the convertor is washing away his torque, We don't know if the flash torque is too low to use the converter to its potential! Trouble shooting this or any other thread is a guess and elimination puzzle! Ive installed these cams and 16*to 18* initial to 25 or 28 off idle and 34 to 38 in at about 2800 was plenty and never had to lock out the distributors to get good response, With a good flash stall converter, taller gears and the right diameter tires. And lets consider the carb Jetting, power valve, accelerator pumps duration and squirt, timing the secondary linkage! All this seems to be taken for granted its dead on! and narrowed to locking out the dist.

Lunati Hydraulic Flat Tappet, Advertised Duration 300/300, Lift .515/.515, Chevy, Small Block, cam: I dont know why but for some reason a comp or isky etc. of comparable size and specs hyd. or solid blow it out of the water on a naturally aspirated engine at 11 to 1 compression, bring the gears and stall up and that cam will really wake up! Im not saying you cant wake up that engine with that cam but I agree that a solid cam would have been a better choice and I could suggest others!

He never even stated his complaint Is it non responsive off idle when leaving a stop light idling at 600 rpm or is it non responsive at the track leaving the tree staged at 2800 rpm and it falls on its face! Does he stomp it at idle and its sluggish till it hits 2500 rpm! If he could explain his problem better and exactly what his complaint was I think I could come in on this thread with you other guys!

How did you come up with the 11 to 1 compression 90 caprice 408? What brand converter do you run #s? Where are you located (elevation)?


And no that cam is not for low end torque, and it was designed for mid to top end and a shot of N. Its gutless at bottom end, Do you bracket race or did you build for power on the street!

Why did you plan a build like this for your first (just curious) Its one hell of an accomplishment for your first build Who suggested that cam to you?

Jester

Didn't really plan this build out too much i guess thats part of my problem...i knew the cam and convertor had to somewhat match so when i picked the cam i looked at its operating range and picked the convertor that was a couple hundred more rpm than the beginning of the operating range of the cam.....I used one of the jegs convertor which is suppose to flash between 2700-3000....being that this was my first build i didn't use a degree wheel i just installed them in dot to dot like how i've seen people i've been around build there engines. I was also leaning towards running 4:30 gears but i don't want to install bigger gears and the car still be somewhat of a turd

[vinniekq2]

The car is not a turd because you missed the cam timing by a degree or two. The stall is not perfect still no big deal. wrong cam? maybe,depends.might be the wrong one for you...definitly not a cam I would ever use.
No one thing is the problem.The problem is everything as a whole package.
What we are going to do is follow Painted Jesters lead.make do with whats here,put some miles on it and plan for the future.
Its going to improve,just be willing to work with painted jester.He has amazing patience.

[gearheadslife]

love to know how he thinks flattops and 64cc=11 to 1 that have to nearly zero deck and no valve releaf's in pistons

[F-BIRD'88]

this cam needs a 9" 10" 3500++ stall converter. Your converter is a bit too tight
but that is secondary to the basic fact that the thing is hurting for more timing at idle.

Lock out the advance curve . It will be a whole new car.
You will need the spark power interupt switch to hot crank/start it with the locked timing.
and get the starter bracket... first...if its missing

The rest, is details.

[painted jester]

Any first time builder can make that mistake when ordering pistons because some manufacturers put a C.R on their pistons without knowing a builders specifics of deck, gasket etc!!!

Jester

Example: S.R.P.
SRP 11:1 Forged SBC 350/383 Flat Top Pistons, .020, .030, .040, .060, (6.0" rod) with 3.75
138096 SRP Forged SBC 350/383 Flat Top Pistons 6.0" Rod .020 $499.00
138093 SRP Forged SBC 350/383 Flat Top Pistons 6.0" Rod .030 $499.00
138094 SRP Forged SBC 350/383 Flat Top Pistons 6.0" Rod .040 $499.00
138095 SRP Forged SBC 350/383 Flat Top Pistons 6.0" Rod .060 $499.00

[painted jester]

Since your engine is in the car do the easiest first !! That would be re curving the dist. initial mid and total with a vacuum advance or initial and centrifugal without one! Try F.B.s lock out first and if it improves we can go down the line with ideas to improve the rest of your problems without changing anything!! You will need a dial back to start it hot and the street manners wont be the greatest when its locked out! But it will eliminate the timing question!!

FB is dead on about the converter! And Jegs was a poor choice but now you have it lets work with what you have!

What kind of driveing did you build this for? Whats your altitude (elevation)? How tall are your rear tires and what speed through the 1/4 or 1/8 are you expecting if you did build it to race!

Jester

Read Cobalts post: "This is one time I will agree to give it a ton of initial timing, even if that means locking the mechanical advance. You can still use (and should use) a vacuum advance. Hook it to ported vacuum if you lock the mechanical advance. Limit the vacuum advance to around 10-12 degrees."

[454C10]

Yes, not enough stall, gear, or timing for that cam.

Compression is a bit high but the alum heads should make it OK. I ran a similar sized hydro cam, dart iron heads, 11:1 and it worked great for me.

Either drop compression and cam duration OR add stall and gear. The engine will need more timing no matter what you do, so try that first.

I would try 38 total mechanical timing and see what happens (listen for detonation). Are you sure the timing marks on the balancer are correct?

What carb do you have?

Do a compression test and check for a flat cam lobe.

You have a big heavy car there. Don't expect too much.

[hcompton]

What about the carb. If its rich or lean it can make it run flat at low rpms. Do you get black smoke out of it when you punch it. Should see a little if its properly rich.

430 gears are a good jump from 373. 411/410 would be good bump up if its right and working well.

Sounds like you got it pretty close just needs final tuning. Build seems to be close to what you need for good bracket/street car. I know others have said cam and cr all wrong but its not that far off from what everyone else is running just needs to be tuned and tweaked.

Checking to make sure the cam is at 0 is a good idea but not easy so I would skip it for now. Play with the timing a little and make sure the accelerater pump is set to its strongest setting.

Does the engine lope badly in gear. Usally if the cam is too big it will lope while your driving down the street below 3K rpm. If its smooth it probably just needs tuning.

Proper Solution:
Sometimes its best to bite the bullet and take it to a speed shop for Dyno tuning with EGT and wideband. You can play with it for a month and one day at the shop will sort it all out. On the dyno a proper tuner can tell if its rich lean too much timing or not enough. they will need to weld in egt sensors into the headers. Its no big deal doesnt effect performance but does effect the cost of the runs. Only take it to someone you know is good.

I recommend dyno because your build is running and driving. Sounds like you built the engine right. Other are saying they could have helped but you didnt miss the mark at all it just needs some real deal tuner to sort it out for you. CR may be high but you didnt say what the car was used for so it may be right on the money for bracket car.

Also does it knock if the timing is set above 32?

[lg1969]

The cam you should have used would be around 280*- 290* duration for setup you have. Try to change the manifold and carb to a Q-jet carb. The Q-jet setup would give you a strong low end response.

[painted jester]

If you could explain in detail Is it non responsive off idle when leaving a stop light idling at 600 rpm? or is it non responsive at the track leaving the tree staged at 2800 rpm and it falls on its face? Do you stomp it at idle and its sluggish till it hits 2500 rpm? If you could explain your engines problem better and exactly what its doing, it would sure help us trouble shoot its problem!

Are you on a tight budget? I'm asking because you bought a Jegs converter and small Summit 1 5/8" primary headers you should have installed 1 7/8"! So I'm thinking you might be scrapping dimes! Its not a bad thing trying to build to a budget But it helps us when suggesting things if we know what kind of budget you have to afford the things like a dino session or a turn back dial!

Jester

[90caprice408]

Originally Posted by painted jester

If you could explain in detail Is it non responsive off idle when leaving a stop light idling at 600 rpm? or is it non responsive at the track leaving the tree staged at 2800 rpm and it falls on its face? Do you stomp it at idle and its sluggish till it hits 2500 rpm? If you could explain your engines problem better and exactly what its doing, it would sure help us trouble shoot its problem!

Are you on a tight budget? I'm asking because you bought a Jegs converter and small Summit 1 5/8" primary headers you should have installed 1 7/8"! So I'm thinking you might be scrapping dimes! Its not a bad thing trying to build to a budget But it helps us when suggesting things if we know what kind of budget you have to afford the things like a dino session or a turn back dial!

Jester

Yes I was on a tight budget and its my first build so I was ordering parts that looked good to me for the little bit of knowledge I had....it runs and drives fine it just doesn't have the umph I thought it would have from a standstill and off idle....but she comes alive around 3k...I don't really want to change much on this setup if I don't have to...this is also just a weekend car so gas mileage is no issue

[90caprice408]

I wanna thank everybody for their quick and helpful input so far......this has been the most help I've gotten off of any forum thus far

[painted jester]

Can you post a few different views of the engine without the air cleaner? right , left , front , and rear. So we can see what we're working on.

Jester

[Oregonite]

I'm running a 400 in my '66 Nova with stock rods and pistons, Vortec cast iron heads. Turbo 350, 2800 stall converter. The cam is a hydraulic flat tappet 280 duration/480 lift, 108 lobe center. I have around 9 to 9.5 compression. It has excellent low-mid range power.