I'd get some quality plug wires. You don't need expensive MSD or mallory or accel, but Bosch or a good OEM replacemt will do. I don't recommend the cheap china wires though.

With that and some tuning, it should (I hope) respond a little better than a stock 350 since it's bored (now it's a 355), and the cam. When all is well there, then I'd put on the intake manifold and headers. If you don't have the corvette mufflers yet, I'd go with some dynomax mufflers, but the corvette pieces sound interesting...

As for "impact driving" I assume it's 4000rpm in neutral then slam it into drive. You'll kill it QUICK that way. My brother had a Merkur XR4ti (think Mustang SVO; turbo 4 banger) and he did that a few times and the rear blew out on him. It's better for automatics to hold the brake down a bit and rev the engine, then let off the brake. Of course, the best is to drive it like a grandma, but that's no fun.:mwink:

********if I am wrong anywhere here, please correct me********

 

The vacuum advance should be connected to a manifold vacuum source, or one that always pulls vacuum. Setting the spark timing properly has to be done if performance is expected, it needs to be around 12 degree`s before top dead center and set there with the vacuum advance disconnected and plugged, once locked there reconnect it. If you have the cam spec card, to know it`s specs would be of help.

 

Is your cam timing ok?
Is your harmonic balancer, vibration damper, crank belt pulley ok ?

Iff you move your timing light around the crank pulley can you see the mark

 

If you're confident that the exhaust isn't clogged, then I would suspect timing and/or the distributor. Follow DV's thread.

 

shouldn't the vacuum advance be hooked up to the "ported" source, not full manifold vacuum? If you're pulling manifold vacuum you're advancing through vacuum advace at idle, and your timing woudl come in way too soon.

K

 

You have to know exactly where your timing is if you want any decent performance out of your engine. Find the timing mark. Clean up what you need to so that you can see it.

Ignition timing improvements can make more of a difference in the "seat of your pants" feel, than most bolt on improvements.

 

Why havent you ditched the stock intake for your Edelbrock unit?

Listen to what people have said and you should start to feel the difference. Make sure what you HAVE on their now is properly setup and tuned and then start to add the other bolt ons. You'll like the headers and new mufflers and should feel their difference once they are on as well.

 

ChevelleSS , Impact driving would be anything to do with dumping the clutch (this is manual) 1.5k, 2k, 3k, anything... Im positive this engine should be making somewhere in the neiborhood of 350 tq.

I want corvette mufflers because of the unique sound and the quad chrome tips (I think it would look cool.. hehe)

Plug wires are on my list.

DoubleVision
t's an Elgin "Pro Stock" Cam
These are the specs on the box.
DURN DUR. @ .050 CAM LIFT Valve Lift Lobe Centers
IN Ex IN Ex IN Ex IN Ex IN Ex
291 291 218 218 0.303 0.303 0.455 0.455 105 11

We where told that 28 degrees is what we want if we want it to have top end performance...

Let me explain this, I want my power to be at 2500 to 6500, I want a high revving engine. If I have more than 300hp or 300tq, my trani will break, guaranteed. And its initial tq that breaks it. Sooo I want to get rid of as much of that as possible.

Do you have a pic of where to put the vacume advance?


Jmark
My exhaust is custom one piece, from a guy who built his 914 and smoged it. I dont have to worry about smog, and I had to get it on the road with something, so im using that.
I'll take it to a muffler shop and have them take out the cat. Im not a good enough welder to do it.. lol
Pic of the port would be very nice, thanks.



Simo
Cam timing fixed.
Custom harmonic balaner from a place that specializes in v8 914's. Should be fine there.

Move timing light where?? lol This aint no front engine car...



killerformula

Currently the vacume advance is off... We couldnt find a proper port to use that wasnt pulling at idle.

lluciano77
See my engine pic.. Is there another way to time the engine than by the pulley? Like maybe by vacume... You know to get it somewhere in the range.. (Keep in mind it feels like 100 hp.. not 235, and im looking for that extra 15... )

Siggy_Freud
I wanted to but dad just said not yet. That is not my performance problem. I will get it running correctly them switch to the high performance parts.

Thanks all!

 

Killer, I ran my car with the vacuum advance on a ported source for years, as I didn`t see the need, why would a engine need vacuum advance at idle? it needs it because idle mixtures and off idle mixtures are lean, and lean mixtures burn slower than rich ones, BOBCRMAN told me to swap mine around to a manifold source and I did, the car went from being a non responsive slug to a responsive small block the minute I did so. As for your question Andy, you can connect it to any source that pulls vacuum all the time, any source that pulls it at idle connect it to it, the difference is like night and day.

 

Then I'll have to completely re adjust my idle. And to think, I just got it where I wanted....

(I drove to church today... and my radiator hose blew off... got two of my friends, and they chatted while I connected it back up.. The line was dragging on the ground and I was going "what the hecks that noise" when I shut it off 100 feet from my church... lol, 8 bottles of water and antifreeze later, (I live 1/2 mile from my church, wasnt much of a problem...)

Ya, it was running 13.5 or so a/f ratio (We have an LM1 unit.. pretty neet toy!) at idle.. We'll play with it a little before I go to work, see if we can get everything to go right...

I can set the idle nicely with the vacume advance off because the idle screw has lots of "play" room, when the advance is hooked up to a always vacume it moved the idle from 900 to 1700... So I really dont know..
Besides, shouldnt the vacume advance be able to change the timing when more (less? im used to turbo's....) vacume comes on?


More suggestions would be great!

Thanks
Andrew

 

Since you have AFR, what is the AFR when the engine starts to become and slug? What is the RPM when it starts to bog? Dont by chance have EGT do ya? If so what is it looking like?

Chris

 

AFR is fine when full throttle or any throttle. Its not out of tune enough to be causeing the severe lack of hp that is being caused..

Its not rpm that it boggs its throttle.. 1/4 throttle is my max before it just doesnt do anything.

at 1/4 throttle its got about 150 tq or so. Pretty good power, but anything more, and it just falls on its face (although it starts to make a great deal of noise... you know, its "kicked in" now...

from BBbbbrrrrrr to VRRRRRRRRRRRRR, just not the hp that im lookin for....

No EGT.
Andrew

 

Killer, I ran my car with the vacuum advance on a ported source for years, as I didn`t see the need, why would a engine need vacuum advance at idle? it needs it because idle mixtures and off idle mixtures are lean, and lean mixtures burn slower than rich ones, BOBCRMAN told me to swap mine around to a manifold source and I did, the car went from being a non responsive slug to a responsive small block the minute I did so. As for your question Andy, you can connect it to any source that pulls vacuum all the time, any source that pulls it at idle connect it to it, the difference is like night and day.

Not to threadjack, but NO KIDDING?! Wow, I'll try that out too, perhaps its worth me messing around with it.

Learn something new every day, thanks DV!

K

 

Ok, we changed the timing, and plugged in the vacume advance. It doesnt like to start, ie slow start (sucks alot of juice, lol, have to turn off my radiator fan to start it....) so dad says it might be a tooth off.

What would be the symptoms of being a tooth off?

Its a little faster, and its a little more responsive. 150, maaaaaaaybe 175hp. I'll have to check with the G tech, and we still need to seat the rings (havent dedicated time to actually sit down and give them a good load.

Andrew

 

Well, the inability to get correct timing by turning the cap could point towards it being off a tooth or two. Poping, lack of power, etc.

Just bring it to TDC and see where the rotor is pointing. Your dad was a mechanic for 10 years he should be familiar with all of this.

 

Oddly enough there is no popping....

I'll have him read this thread... im going to work..

 

Well, I did not ask if AFR was fine but what it was. How about some numbers.

Chris

 

Hi everyone, I'm the Dad.

The timing seems to be about right.
8degrees initial
22 with the mechanical advance kicked in
around 30 with the Vacuum advance added to the mix.

We'll try backing down the initial and see if it cures the slow cranking. We were around 2 degrees retarded and cranked pretty good.

It may be off a tooth, the big HEI give it more room to move before it hits the intake. Still have a bit more to go. So, if I can get the timing spot on, does the 'off a tooth' matter. Yah, I was a mechanic about 15+ years ago, now I can't even spell it.

Anyone have a picture of their dist and where it is pointing?

Thanks, ( Great place I need to spend a couple hours in the archives...)
Dan the Dad

 

Timing is WWAAAYYYY to slow. You need 36 mechanical without vacuum and around 45 with vacuum. That is most likely the problem. I would recommend bumping up the initial to 15 or 18. You want as much as possible and still have the engine crank and not detonate under load. If your dist. is only giving 14 mech. advance I might even go as high as 22 intial if it will take it. I run 24 initial and 22 cranking advance on my turbo engine.......just so you know it can be done.

I have not read back to the one tooth thing. If you are talking one tooth on the timing chain, that is REAL bad. If we are talking on the distributor it does not matter. Just set timing correctly.

AFR should be around 12.5:1 at WOT in higher RPM, but in lower RPM at part throttle a bit leaner will be more responsive.

Chris

 

The only reason being 1 tooth off should affect it is if you dont have the physical room or play to move the cap to account for this. In which case you can either take out the dist and try and fix it, or bump the spark plug wires one over in their places. It doesn't really matter where the dist is pointing as long as its relation to the rotor being at the #1 plug spot when the #1 cylinder is TDC.

 

Timing is WWAAAYYYY to slow. You need 36 mechanical without vacuum and around 45 with vacuum. That is most likely the problem. I would recommend bumping up the initial to 15 or 18. You want as much as possible and still have the engine crank and not detonate under load. If your dist. is only giving 14 mech. advance I might even go as high as 22 intial if it will take it. I run 24 initial and 22 cranking advance on my turbo engine.......just so you know it can be done.

I have not read back to the one tooth thing. If you are talking one tooth on the timing chain, that is REAL bad. If we are talking on the distributor it does not matter. Just set timing correctly.

AFR should be around 12.5:1 at WOT in higher RPM, but in lower RPM at part throttle a bit leaner will be more responsive.

Chris

Thanks for the replys.
It barely cranks over as it is with 8 initial.

Will an advance kit allow for more advance or just change the curve?

It's possible that I'm getting false readings on the timing light. It's almost impossible to see the alternalte timing mark that the kit manufacturer made. It's definatly impossible to see the original timing mark. I'm debating to setup another timing mark on the flywheel. Anyone here ever do that?

Thanks Siggy for clearing up the tooth thing. I was once told that it had to be in a certain position to work. I just couldn't get it out of my head and I couldn't make it make sense. (if that makes sense).

 

AFR was in the mid 13's under no to small load and at idle and dipped into the 12's (plus or minous a point) under load. We'll rejet it on the dyno with a little better readings.

 

I am not sure what to recommend on the timing. You definately need to know for sure what is going on. I really think that you should be getting more mech. advance from your distributor. You could modify the wieghts for more advance. You will see how when you get it apart I think.

I should have asked before, but is the AFR meter a WB unit. I made the ASSumtion that it is on of the LSU4 variants that are out there. If it does not use a WB sensor, DO NOT tune using it. The units that use NB sensors are JUNK. The reason I bring this up is because you say AFR is varying by a point up or down. That is huge. 13.5 is way lean for WOT and 11.5 is way rich for NA engine. I have never used WB on anything other than EFI so it is possible that a carb could fluctuate that much, but I would not think so.

Chris

 

you mentioned two different carbs, which one are you trying to use? Almost sounds like a fuel/air delivery problem to me. 1/4 throttle pulls good, beyond that it suffers? A/F numbers dictate that.

 

Yes this is a wideband.
http://www.innovatemotorsports.com/

Honetly, AFR is not the problem here. Its in the range and thats what counts. That little bit of tuning will maybe pick up 15 hp.

When I drove it I thought that was the problem, but the numbers do not show that much possible improvement.

I think the timing is possibly the problem.
The only thing is that it barely cranks over at 8 initial. I have to turn off my fan, and any aux items to start the car. What do you guys think?