[DoubleVision]

I would get a holley carb and throw the adapter in the trash. This is part of the problem itself. Open adapters disrupt flow, vacuum signal plus hurt low end torque.
If the vacuum advance isn`t connected to a manifold source then do so, see if there is a major difference. If ping is detected you`ll need a adjustable vacuum advance unit. The combo were running is similiar to yours and it runs like gangbusters.

[heathj1]

Go get a 3310 holley 750 vac sec

[F-BIRD'88]

The Qjet will need recalibration to work best on a modified motor.
The open spacer effects the bottom end torque.
You need to find a Qjet to square bore adapter that is fully divided to maintain the dual plane split plenum under the carb.

You must degree in the cam in order to establish its present valve event timing in order to move it. (if you don't know where you are now, how do you know where or how far to go?)

The distributor timing curve will need a bit of work with the new cam.

What about the exhaust system?

[Chevy21]

Well, I didnt get a chance to do the compression test on it tonight. The vacuum advance unit is hooked up to manifold vacuum. Before the swap, I did buy an advance kit for it. I think I ended up using the two medium springs. The exhaust is Hedman 1 5/8 headers into 2 1/2 in. pipes with bullet mufflers. Does anyone know where to buy jets and metering rods for q-jets? I guess I wouldnt know where to start with those. Well, in the meantime, I will look for an adapter with a split plenum. If worse comes to worse I may have to tear it back down to see where the heck I went wrong.

[cobalt327]

Originally Posted by Chevy21

Does anyone know where to buy jets and metering rods for q-jets?

HERE is a place that has a LOT of tuning parts for the Q-Jet, some that are hard to find like the power piston springs in sets that you don't have to buy a ton of other tuning parts to get, like w/Edelbrock.

Edelbrock also has some jets and rods, etc.

[Chevy21]

Well, we found the problem last night. We took it out for a test drive and found that the motor was also backfiring through the carburetor. We ended up pulling the valve cover and could visually see that the exhaust valve on #8 cylinder was not moving very much. We pulled the rocker and measured the push rod travel with a dial indicator. The intake and exhaust valves next to the bad one measured what they were suppose to at .308 intake and .317 exhaust. The bad exhaust one only measured .175. So anyway, I guess the new comp cam that has less than 1 hour on it shaved a lobe off. Can't say I'll be buying one of those again.

[oldbogie]

Originally Posted by Chevy21

Well, we found the problem last night. We took it out for a test drive and found that the motor was also backfiring through the carburetor. We ended up pulling the valve cover and could visually see that the exhaust valve on #8 cylinder was not moving very much. We pulled the rocker and measured the push rod travel with a dial indicator. The intake and exhaust valves next to the bad one measured what they were suppose to at .308 intake and .317 exhaust. The bad exhaust one only measured .175. So anyway, I guess the new comp cam that has less than 1 hour on it shaved a lobe off. Can't say I'll be buying one of those again.

Camshaft break-in is very difficult and critical these days, with anti-scuff additives being deleted for oil it is critical that the cam manufacturers break-in instructions be follower to the letter. This includes using ZDDP heavy additives as recommended by the manufacturer.

Frankly when using a cam that requires valve springs with a greater force than what a wimpy Gen 1 SBC in a pick up would have had, what you need to do is use these weak OEM type springs for break-in. After getting some time on the engine and getting it dialed, then replace the springs with the high performance stuff. This can be done without pulling the heads with an air compressor to hold the valves shut and a tool for the purpose.

Bogie

[Chevy21]

Well, I used the cam lube that they supplied and used a bottle of their break-in lube as well. Ran the cam for 30 min. between 2000-2500 rpm. This cam was not that radical of a cam. I think that maybe cam manufacturers should be changing the process in which they make thier cams if oil companies are no longer putting additives in their oil. These particular cams must be made of soft material or something. Either way, I do not plan on doing business with them anymore.

[carsavvycook]

I have never had a problem with Crower, Crane, or Lunati camshafts.

Take your pick.

[carsavvycook]

Originally Posted by watchdude1

Just curious
I have a 350 chevy i changed the heads and cam don't know what my stall converter stall limit is, when I floor the throttle the tires seem like they are spinning but i don't hear no screeching sound , just a spinning noise, does the tork converter stall out the engine when it hits it,s limit like 1500 rpms? how do they work!

It sounds to me that your transmission kick down cable is not adjusted correctly. How did you adjust it?

This cable adjustment effects the internal transmission pressures, and shift points.

I just witnessed a transmission builder chewing out the owner of the engine builder/installer today, about the transmission only lasting for 25 miles, and the kick down cable bracket being wrong for the setup.

Stephen

[Steel]

Originally Posted by Chevy21

Well, I used the cam lube that they supplied and used a bottle of their break-in lube as well. Ran the cam for 30 min. between 2000-2500 rpm. This cam was not that radical of a cam. I think that maybe cam manufacturers should be changing the process in which they make thier cams if oil companies are no longer putting additives in their oil. These particular cams must be made of soft material or something. Either way, I do not plan on doing business with them anymore.

Depending on what your looking for in a cam, I would personally look at going to something custom ground. I've had good luck with Bullet cams and for the little extra it costs it's well worth the money....

[TroyBoy]

I've had good luck with Crane,Summit and Comp.I have had 3 Comps, 2 of which I had pulled and used in other engines with no troubles.I also used the lifters that I used with the cams in the correct order.

[BugRod]

I have been running comp cams in my race motors for years with no problems. On another point mopst cam companies get thier blanks from the same suppliers. I always use an older set of springs when breaking in a new cam, that puts less pressure on the lobes while they break in.

[k-star]

I have probably used more comp cams in engines then 10 guys here put together. I have never had one of them ever go flat.

99% of the time the cam gets blamed and it's another issue.

I have only ever had 2 cams go flat, a lunati and a white box, Both were around the time of the big lifter de-boggle.


Keith

[cobalt327]

While I've installed far fewer cams than a pro like K-star (not done for a living), I've not had any issues w/Comp's cams. I had a run of three Comp cams right in a row at one point, all fine. The time I've used their cams (not exclusively) spans nearly 30 years- from when they were known as "Competition Cams".

Of the two cams that went south on me, one (Lunati) was because the pivot ball was installed upside down (long story, but not my fault for installing wrong, but I didn't catch it, either...), the other was a BBC (big Crane solid lifter cam) that didn't rotate the lifter on one lobe and this wasn't seen in time at start-up (v-covers were on), or during setting the valves- where it might have been. This engine even had the inner spring removed for break-in.

In both these cases, the cam would have failed- regardless of who made it, IMO.

FWIW, Comp has a nitriding process that is available as an added cost option. IIRC, it was about $100 extra.