ok i've finished installing a new cam
SUM-1107 - summit racing cam...
http://store.summitracing.com/partd...PartSearchFlag=

into a new rebuilt 305 bored 40 over engine

when i try to start it..

IT cranks and it sounds like every once in a while it gets a good spark and wants to start... but i think i have the key turned on to much it floods itself with gas...

theres spark becuase i've had it running before but i don't know if the guy who was trying to fix it with me "re-adjusted" the valves..

but today when i turned them down 1/4 of a turn to the left " loosing them" it started alittle better "heard more loudness" lol (running straight headers)

thats another thing.. my friend thinks we need to put some pipes and the mufflers on to create some back pressure. he said that might be it...


Help thanks.

 

First and foremost. Thats a HUGE cam for a 305. if you are keeping the TBI, you wont run right. I doubt not even tuning will make it happy. What brought you to selecting that cam?

Oh yea, ignore your friend. back pressure is bad. Not to be confused with delta pressure, which is the difference BETWEEN the pulses. Back pressure is the resistance to flow. You don't want that. The factory exhaust needs all the help it can get; so much so, that it needs replacing.

 

see thats the thing ... my friend (works alot on cars) thought my car can handle it

 

stekman

 

All that aside....assuming factory heads, you're hitting clearance issues before the cam is done lifting.

Basically, factory heads allow for ~.480ish lift before they run out of room between the bottom of the retainer and the top of the guide boss. Meaning, at about that lift, the retainer hits the guide boss and the valve can physically go no further.

your cam has .488/.510 lift. Just before peak lift is reached, your heads bottom out. Your cam still rotates and keeps lifting. Ever try to push a wall? That;s whats happening to the cam. It wants to keep going, but cant. Things come to a halt. If you're lucky, you bent a pushrod. Depending on how many times you've cranked it, the cam itself may be toast. After pushrods bend, the cam is the next thing that gets ground away.

 

yupyupyup....besides if you built this 305 up throw some heads to fit that cam (if you can find any) and you will be up there with some power. but that cam is jsut oo much right now.

just a question...whyd you deicde to go with the 305??? i was comtemplating it but decided a stroked 350 is the only way to go

 

well i got it for $200 rebuild/bored ... so blah..

but i still think it will work... (my set up)..

the push rods aren't bent or anything.. i see them working fine its only that i think its too tight and need to loose them up...(gonna re-adjust them) either that its the timing

i did drive the car once when it wasn't idling right... somehow we had it .. until we adjusted the valves then it stoped firing up...

before we adjusted them.. it would start right up.. with no lag or anything...

but right after starting up.. if we turned it off and tried to start it up.. it wouldn't work ..

we would let it sit for a while then try it again and it would start...

thats when we thought we need to adjust them. becuase we tought the hydrolic lifters where building too much oil pressure that it **** up the engine...

yea but like i said it would start up but have trouble idling.. which we were told it would do... until we got the eprom chip installed ... which i got installed now but not starting up

the car would have to be around 1500 rpm... if it got lower.. freaken car would lobe like a bitch

o well i guess i'ma keep trying and very deterimed to get it running

 

too much cam!

i have the 1103 in my 355, it has a good lope, and its a dog until 3500-4000 rpms then it turns on and pulls very well. I have 3.73's which really help, but i think i might of picked a little too much cam for a daily driver and i have a carb i can tweak.

With your cam its gonna be a dog under 5000rpm, and with tbi it'll always run funny. bad bad choice.

 

oh...where to start? well lets start with the valves. with that cam it wont idle right. ever. especially with that tbi. then when you adjusted it is very possible you didnt have enough clearance and bent a pushrod, valve etc. to check your pushrods you have to take them out and roll them on a glass surface (glass cutting board for example) to see if they are bent even in the sligtest degree. if they are you will have bigger problems down the road so i suggest you check them for sure. but once again, that cam (even if you get it running "right") is going to idle like crap especially down low. hopefully, if you did have some clearance issues the cam isnt fried like stekman stated, at least youd be able to get a little money for it. but if i were you id pull that cam, check my pushrods, and grab a better suited cam, you gotta remember, the better a car runs at lower rpm's the more fun on the street!!!!

well just my on that. but good luck man!!!! 200 bucks is a pretty good deal, was that everything?

 

I'll agree with everone else here, WAY to much cam for a street 305, another thing, that's a flat-tappet cam, the engine you bought does have regular lifters on it doesn't it?

Vendor Summit
Product Line Summit Camshafts
Cam Style Hydraulic flat tappet
Basic Operating RPM Range 3,000-6,500 RPM
Intake Duration 050 inch Lift 234
Exhaust Duration 050 inch Lift 244
Advertised Intake Duration 292
Advertised Exhaust Duration 302
Intake Valve Lift with Factory Rocker Arm Ratio 0.488
Exhaust Valve Lift with Factory Rocker Arm Ratio 0.510
Lobe Separation (degrees) 114
Intake Valve Lash (in) 0.000
Exhaust Valve Lash (in) 0.000

You would have to be running a high compression 383-400 for this cam to run ok on the street and thats with a carb, forget about getting the stock TBI to run right, or at all with it, even with lots of chip burning.

 

Well, here it goes:

You have TBI compression. Low. A camshaft that radical has a radical valve timing. Due to the tremendous duration, valve timing is thus, well, aggressive. Compression ratio in and among itself is one thing, the cylinder pressure is another. Because that cam has such an aggressive valve timing, the intake valve closes much later than what it SHOULD to be EFI friendly. This means thay, yes, air gets dumped into the cylinder, but, as the piston travels, air actually gets out (back into the intake) via the same way it came in. Losing total air volume drops the cylinder pressure which can be associated with dynamic compression.

That same valve timing also affects the amoung of intake reversion. When the engine is running, the cylinder gas backs into the intake. EFI does not like this. EFI wants the exact opposite.

Fuel economy and emissions. Also take a hit. Because the cam has such a large amount of overlap, when the intake valve starts to crack open and fuel and air are first let in, the exhaust valve is still open (its closing, but none-the-less, it's still open). Some fuel basically goes in through the intake valve and right out the exhaust valve. This is not good for the oxygen sensor. You will get strange readings from it because of it. Yes, overlap increases high RPM scavenging, but at the low end, it lets plenty of o2 go in and out. o2 gets the idea it's running lean. More fuel gets dumped in.

Vacuum. Will be non-existant. Again, because of the aggressive valve timing and the intake closing point and the overlap, your vacuum will be next to nothing. Don't expect your brakes to work. The cam will have plenty of overlap. Above 70, thats for sure. That's not a street overlap, that's a race cam overlap. Vacuum is going to take a hit. Everything vacuum operated will get effected. PCV, EGR, fuel EVAP, brakes, everything.

Transmission. Particularly, stall speed. Your stall speed now is at 1500ish. That cam needs about a 4000 stall speed to be happy. That cam doesn't make any power until 3000. So, when your converter finally stops slipping at 1500 rpm, your engine is playing catch up for 1500 rpm. Your car will be a dog off the line. You're going to get walked right and left.

Cylinder heads. Like i said above, you don't have enough clearance between the bottom of the retainer and the top of the guide boss to run that cam. No, you can't just let it go. The cam will be toast. you've probably already started wiping out cam lobes. Not just 1 or 2, but all 16.

Air flow. A cam like that needs a lot of upper RPM air flow to feed the engine. TBI heads are of the worst heads to do this. You will choke the engine at like 5000 rpm, ported or not.

Tuning. The cam is a race profile. Being a race profile, many of the sensors are going to be taking the hit from it. Tuning will be a nightmare. Sure, it can be done. But, after all the above, I would just skip it.

Yes, I was brief in some areas, but you get the idea.

On a side note, not that it really matters at this point with all the things that are not going to work right, what lifters did you use?

And for the record, its "bored .040" over."

 

yea its bored 40 over and using some hydrolic lifters summit gave me with the cam...


oh well i know it will run.. i've driven the car before.. brakes worked fine.. engine ran good.. sounded extremely good.. only thing was that it wasn't idling.. which i was expecting..

i know i will have the car running and when i do.. the car will be sweet..

heres the list of what exactly i have put into the car excluding the stock stuff

305 tbi engine bored 40 over
the good old summit cam(the big one)
the summit hydrolic lifters that came with the cam
summit long style headers
67' Camaro push rods
High compression Alluminum Flat Top Forged Bored Pistons... (not sure exactly what kind or anything) but mechanic who sold me the engine basically said they were high performance onces and since he bored the engine himself he did the pistons too

EVERYTHING ELSE THAT THE ENGINE NEEDS TO RUN IS STOCK
the heads, manifolds, electrical, etc. . .

so YEA BLah to whomever thinks this car won't run

 

LOL
blah to who ever said that engine wont run ?
i think that they should have said that it wont ever run right .......with stock heads that havent been ported or had larger valves and a stock intake and tbi your never going to get it to run correctly with that large of a cam in there ......good luck

id either get some better heads and find someone that can program and tune your computer and buy a better and bigger throttle body for it or swap over to carb and intake but your still gonna have to buy better heads or at bare minumum get larger valve springs

you may have had it running once but it is never never never going to run to its potential or even close to it with what you have in there right now

you pretty much have what i have in my truck right now except i have a stock came...lol.....but im not doubting you had it running im just saying your not getting it running right

 

im sure it will run. Its not gonna run very well, but it will run. I hope you are the guy lined up next to me at the track though.....

 

if u insist on trying to get this motor running id
do a cranking compression test.if its below 110-100 psi ,then probably gas has washed your cylinders .first make sure your distributor is installed correctly.I would then deflood the engine.i dont know what kind of fuel system u use so ill assume its a carburator.crank the engine with the gas pedal to the floor for at least ten seconds.remove and clean the sparkplugs.Change the oil.if still doesnt start ....well it time for a 350.

 

He has TBI, it doesnt really sound like its flooded. I douvt he could have washed the rings that quickly either. Sounds to me like the valves are still lashed too tight. He said that by backing them up 1/4 turn it helped. Keep going. Loosen them all a little, till they are kinda loose, and then try starting. if it starts, go to each valve, back it off till it taps (unless it already is) and tighten until it stops. Then give it 1/2 turn more. I think you would be best off though going with a smaller cam. No one was trying to dog you, or ridicule your choice of cam, they were actually trying to explain to you why it wont work.

This is fact. A dog on an 8 ft chain can only run 8 foot. A spring that can compress to .480 lift, cant go any farther without some sort of mechanical failure. Do yourself a favor, get rid of the cam. Get something a little more manageable. Of course, you really need to ditch the TBI heads too, but you can work with those, just get a cam within its functional boundaries.

 

now i dont know if this was meant with any seriousness but if you are really taking that attitude towards it then please dont ask for any help. we are telling you facts, you asked whats going on and we are telling you why it wont run anymore. you may have had it once but due to some issues weve explained it wont ever run to its full potential. hopefully you didnt bend too much when you ran out of lift but we all make mistakes. i think if youd try a little smaller cam youd benefit more especially with those heads. if not you can sell it one here for very close to what you bought it for. and you have a lesson under your belt. once again, id rethink your selection, possibly your mechanic (since he didnt cathch these problems) and be happier.
but good luck again and id still like to put my stock 305 tpi against this monster cammed stroked 305 tbi anyday :lala:

 

when i have it running and have gotten some miles under its belt... sounds good...

well i went around these forums and found some guy with the valve adjusting topic.. well i used his 3) way and MAN! . i guess that was it... cuz right when i finished adjusting them... just now i cranked it and WOW what a difference.. i started to smell more exhaust then before lmao for once.... well i think i just need to find the timing.. which i'ma do once the battery charges...

well yea i did get them ported and poslished and...

i also got a chip burned for the cam and also to disable anything else that will "disallow" (lol) the engine from running...

if forgot to to put that on my list


so now i'ma wait 15 ish to go try and find the timing sweet spot to get the car to HOPEfully idle someway

 

well by the time you get that thing running right off the line with that cam ill be eating my sandwhich at the finish

but hopefully it was just the valve lash and the timing then all of us just looked past the obvious....keep us posted!!!

 

see when you dont post all the info it screws us up here...LOL....but you are still not going to get the full potential out of that large fo a cam for sure

but i hope you got it running good luck and youve got a long road ahead

 

blah!, i know everything

I dont understand why people ask for help and then argue in overwhelming opposition.

 

AMEN TO THAT ....LOL

 

rgr that... i'm not the mastermind for the project.. just the owner and the one who is paying for all of it so blah..

o well... ALMOST ! HAD IT ! AHH.. very close.. recharging battery...

meanwhile
pix

www.enrique3693.com/pix/1.jpg
www.enrique3693.com/pix/2.jpg
www.enrique3693.com/pix/3.jpg
www.enrique3693.com/pix/4.jpg
www.enrique3693.com/pix/5.jpg

 

if you are the owner and the one paying for it then call that mechanic friend of yours up and tell him to get his *** over and help hes the mastermind that told you to buy that big of a cam for your set up ...LOL.......and whats with all the so blah.....stuff ????...LOL :lala:

 

i know .. he's the one who is gonna probably find the problems with the valves and timing.. once he comes and looks at the car sunday... but i'm just trying to do it myself since i know alittle but...

that is why i'm messing with the valves and timing... .. just maybe i get it running and we get a step foward..

he knows for sure that the stuff that we've put into the car will work.. i'm just going around forums asking for any extra help...

extra opinions don't hurt...

just posting around ... maybe theres someone who has tried this before.. either that i'ma be the first lmao..

alright its about time to try to start it agian be back in like 10 min or so...

BRBRBRBRB

 

not cool... stupid charger = weird ... lets try 30 min...