Ok This is not your normal camaro realm question but hey.. why not ask..

anyhow..
I have a 1991 Caprice police 350 (9C1 - hydraulic roller cam)
Was throttlebody but put a 1987 camaro z-28 intake on it and a holley truck avenger carb. I believe the intake is messing me up. Anyone know the difference of putting a camaro intake on instead of a dual plane intake?
I believe I will need to change the intake as it seems that I have to floor the truck everywhere.... think the intake is hurting me vs putting a torque'er intake on?
I know the question is hard to see but hey yall hopefully know where im going with this..

 

The factory 305 manifold is a dual plane. Your problem is elsewhere. Putting a Torquer on there would be a good way of making a bad problem worse.

What did you use for ignition?

 

Ignition??
All I did was put a carb intake on and my front end stuff, z-28 intake and a holley truck avenger 670cfm carb... used my ole distributor with new wires, plugs, cap and rotor...

here is what I posted on my truck sites I am a member of...

also I appreciate the help....




Boy oh Boy.. it is such a nice feeling to have the truck back on the road... Well sort of a nice feeling...
GAS price is up and my truck MPG is DOWN more than 1/2!!!!

anyhow... I have serious motor problems... Can anyone assist?

Here is my delema..
do I
1. replace the cam and intake
2. buy a 350hp crate motor (350 4bolt)
3. drop in a stock used 454??

Ok this is what I have..
1991 Caprice police 9C1 350 2bolt
1987 stock Z-28 intake (used to be TBI)
hydraulic roller lifters
supposedly 195hp / 350ftlb torque

Well I am getting about 4.5mpg!!! for that might as well put in a 454!!!
For some reson the truck cant get out of its own way...

I laid 2 - 8 foot posi marks outside of my friends house in first (not granny gear)

If I start out from a light... the motor tachs to 5000rpm quick...
shift into 2nd and floor it.. I can actually count to about 8 seconds till it is time to shift (approx 4500rpm)
then shift into 3rd and floor it till my needed speed (required speed is felt and speedo not used as it is not accurate)

So
If I go with choice 1 what cam should I put in?
the motor is a hydraulic roller so I believe I have to stay with that? if so what size, lift, duration???


If I go with choice 2 it is obvious as they can be had from GM for about $1200 with a warranty

If I go with choice 3 it is a used 454 complete.. remove my motor and drop this in for $1000

ASSISTANCE ANYONE!!!!
P.s. I dont have the $$$$ for choice 2 or 3 and will take time to get it but if it is the best choice then that is what I want..


I am trying to get around 10mpg.. that is why I didnt go big block in the first place...I want the truck to make a trip to NY or Maryland, Bloomsburg PA..... but if a BB gets me 8mpg and there is no other way for me to get any better with a small block then hey.....

 

If you used the 91 distributor, that is your problem. It is computer controlled advance. You need a vacuum one....

 

Thanks for the reply..
I used my 78 one.. all external stuff from my 78 motor went onto this motor....

 

check for vacuum leaks and your timing.

 

How did you adapt the carb to the intake?

 

intake was a carb intake.. so I just bolted on the carb and went...


aight I was crying wolf.... I just went and filled her up... took 5 gallons... not too bad I guess.. still 7mpg. better than 4.5

so I also noticed why I thought it was worse... I thought when I filled it up that the fuel gauge went beyond full so 1/2 tank was 9 gallons... and it was a bit before 1/2 thus 7 gallons... well it is full now and the needle is before the full mark... not even touching the line....
so tomorrow I am going to adjust the carb by setting the timing, choke, fuel mixture and floats... hopefully I can get better... also maybe if I dont mash it all the time I can squeeze 10mpg... we will see....

more to come so stay tuned.. but I believe I should still get a different intake though...get rid of this 305 z-28 intake.... Sunday someone may be coming for my dirtbike so that will help!!!

 

Just bolted it on? The 87 Camaro intake was a spreadbore pattern, and the Holley is a squarebore pattern. Without an adapter you have a HUGE vacuum leak.

 

Holley carb could be spreadbore, but it's worth checking.

 

no it isnt a spreadbore.... so there is a vaccuum leak that way???
you may have found a big hole that I was unaware of...

basically the primary and secondaries are all the same size... so I need an adapter plate? should I also get the performer intake anyway? or try the adapter first???

here is what I have...
http://holley.com/HiOctn/ProdLine/Pr...C/0-90670.html

 

Right, that carb is a squarebore carb, and needs an intake designed for it, which the factory 87 Z28 intake is not.

Spreadbore was stock on the 87, and would look similar too this:
Spreadbore intake That is aftermarket, and stock would look similar, with the exception that it would have 2 smaller holes for the primaries and 2 larger holes for the secondaries.

A squarebore looks like this:
Squarebore intake

Bolting on a squarebore carb on a spreadbore intake with no adapter will create a ton of problems.

 

well now another question!!!!
I posted elsewhere but did fix my power issue... and now have failed emmissions.... Ill chop other posts here...



On my way to inspection I rolled through a inspection check... guy just shook his head and waved me by.. I have a 1998 sticker on my truck... but he knew that since I had the pink paper behind it and that I was heading to the inspection place that that is where I was going.....

Truck failed inspection... Like I expected it to pass!!!! guy didnt even put a rejected sticker on so now I still have my 1998 sticker on there as if I never went!!!!!

Ok first some of the minor stuff..

1. Pitman arm nut too loose... I believe the nut/shaft is stripped so I may need to goto a junkyard saturday and get a new shaft and nut

2. Front Ubolts loose... the bottom leaf is even a little spun out of wack.. the guy said while he had me rock the wheel back and forth he noticed the leafs are a lil loose.

3. Power steering belt loose so it makes the chatter when trying to turn the wheel. It wasnt that bad before I got there but now it is bad.. ok so no biggie just a new belt...

4. Emmissions - this is a toughy.... need suggestions



Ok so my hydro carbons are allowed 3.00 and I was a 3.63. I do not know if that is seriously bad or not. Obviously I failed so it is bad but I do not know how far that is off.. Anyone have any suggestions? A friend (racerop) told me that there is this stuff that you put in your fuel and it burns HOTTER thus eliminating alot of the hydro carbon. Also would MSD ignition or whatever it is called be better? since they create a hotter spark thus burning more fuel?

I was told that hydro carbon is just the means of saying too much fuel not burning????

I am set to go back on 12/23/2004 8:30am


Since I failed the few stuff above and emmissions I did not get to do the tilt test..... but I did pass everything else... lights, turn signals, horn, brakes, etc....


The guy even tried adjusting my holley and still didnt pass... he said that it was so close..... I do notice that since he adjusted my carb idle mixture screws that now the truck pings in 3rd gear full throttle.... timing too high?
I may just pay a mechanic the $75 to adjust the timing, choke, floats, idle mixture screws, etc....

__________________________________________
next of my posts...
ok after reviewing my failure papers I was wrong.. it is not hydro carbons like the guy said when he handed me the papers.. this is what my results were and see if anyone can a$$ist.....


NOx - no readings
HC Standard 300 Reading 267 Result Pass
CO% Standard 3.00 Reading 3.63 Result Failed
CO2% Standard blank Reading 9.5 Result no standard so passed
O2% blank
RPM 1471 - guy had me hold it there second time


anyhow CO is carbon monoxide right? if so how what do you adjust to get that down or will the guaranteed to pass lower that?
____________________________


eveyone is telling me to use that Guaranteed to pass.. does that stuff really work????