Inliners International Forums General Discussion Hi Performance New Guy Here. 68 Camaro with an L6 250.

I think I just about got it. The power valve lever was adjusted too low (too close to engagement). The more I back it out the better. It doesn't need the power valve until 90% throttle from the feel of things.

...getting closer.

Also fooled around with the timing. Bumped it up 2 degrees. Gained a little power there.

Regardless I'll probably just take it to a pro I know locally for a dyno tuning session. He does a lot of classic SCCA cars and knows what he's doing. My wife and I are talking about taking it on a 300 mile long weekend road trip this spring so I plan on having it done right before then.

On my to-do list:

New radiator
New temp sensor (and moved to t-stat housing)
alignment
different, quieter muffler with exhaust exit moved to back of car instead of dumping behind wheel.
Carpet trunk with sub and amp installed
new shocks all around
Balance the tires

I'll bring some tools and spare parts with me but I should make it with no problems after that list is done. She's running really, really well.

Hi, did you notice that on long drives where you use 3/4th of the tank of gas that your tank gets pressurized? It was a mystery, but then I realized the muffler is right next to the tank which probably causes it to heat up to some degree and create positive pressure. The trunk gets plenty warm from the muffler. The exhaust pipe runs only an inch or two from the rubber portion of the fuel line. That can't be good either. At least that's my theory.
Mark

Never had that problem even with the old, stock set up which put the muffler right behind the diff in the cavity between the diff and tank. My new set up has the muffler sitting under the rear seat on the driver's side.

Sounds like you need a new gas cap. Mine is vented and shouldn't ever have that problem.

So I bought a new 3 row radiator off Flea-bay. It's a cheaper one but the pics look like it has good welds and a solid design. Also ordered new hoses and a new temp sensor. I don't think my temp sensor is working now so for $6 it's good insurance. I will probably be buying a new 3 gauge cluster to sit under the dash just so I know what my actual oil pressure, temp and RPM's are.

Next week will entail some evening garage time for me! I also plan on doing a home-made radiator fill cover like this:



I have some good sheet plated metal from my dad (he works at a high end steel mill and can get me "scraps"). I plan on cutting it to fit, plasti-dipping it black (nice flat finish with a satin feel to it), and finishing the edges with a cut vacuum hose (one slit in it, slide it over the edge). Should help finish off the front end a bit and help direct airflow through the radiator.

I also plan on getting a new muffler next month. Any recomendations? The flowaster 10 has a nice sound but it's just too loud. I'm looking for a relatively cheap 2.5" x 2.5" center/center muffler around $100 range with a nice sound and a bit quieter than the 10 series.

One final thing I hope to figure out is the secondary on the 390 Holley. I'm starting to wonder if the plunger arm is actually correct in the rebuild kit I have. The old one was still good but since I was in there replacing everything I did that too. Now I wonder if the arm wasn't wrong.

Like this pic shows:



So I'll pull it all apart again (besides I need to reset the cold idle anyway) and compare the old one to the new and make sure they're the same. If not I found my problem. If it is the same then I'll move on to the squirter and check it out.

That cover will look good. The reason I asked about the other radiator is mine in the nova is shot. Compared to your 2 row in the picture, my core is closer to the fan. When I went to the clutch fan it's pretty close to the core. I thought that if I could get a 2 row like the one in the picture I would gain a inch or so. Do you have a fan shroud ? All I have is a top plate with a fan guard. Maybe they sell one as a Camaro restoration part. Jay6155

It's a single core.

I've seen different sized fan spacers online on Ebay. You can try a shorter one.

No fan shroud either. Didn't come with one So I've never had it.

I might make one integrated with the cover. Depends on how good I am at welding the sheet metal.

Thanks. I have no spacer, just a factory clutch fan bolted to the water pump pulley. The clutch is of course in front of the blades and gets close to the core. A two row will be ok for me if I can get one with the fins closer together. If I do a recore I will have them turn the core around so it is shifted towards the front of the car like yours. The shroud idea was just icing on the cake. Does your new radiator have plastic tanks? Jay 6155

No plastic. It's all tig welded aluminum.

That will look nice. I want to try and keep the stock look f I can. Jay6155

Well if you want my old one let me know. The upper hose neck needs some love but she holds fine.

PM sent. Thank you. Jay6155

gbauer,
IIRC, if you have the wrong secondary rod it wont physically work right. So, U might not need to tear (pun intended) it apart. Just operate it by hand, if it seems smooth and stays open when you cover the signal hole[s] (you have to pull the lower throttle body to do that though) it should be fine

Try it on the road, with a paper clip on the rod. See how far its opening as a function of RPM. Easy test to do, then you know for sure.

I'll pull the carb tomorrow night and see if the plunger matches what came out. If it does then I'll try the paperclip Trick.

Got busy tonight changing oil on my daily and putsing around with the radiator fill panel I'm making. Got the pattern right. Now just time to cut the sheet metal.

On another note: tin snips suck. I want to use my grinder to do it but not at 10 pm in a crowded neighborhood. I'll wait on that until Saturday morning I guess. Plenty to do until then... maybe I'll stop by Harbor Freight and see if they have something better to cut a 20" line of sheet metal. The plan is to make two identical pieces and weld them together in the middle, grind it smooth, plasti-dip it black, and edge it with a piece of vacuum hose with a slit in it. I saw a trick on one of the Saturday morning car shows for doing just that by making a jig out of a scrap of 2x4 and a razor blade.

I have the sheet metal. Spent a whopping $7 on the hose and $15 on the plasti-dip. If it looks good for $22 then I saved about $100 from buying one.

I think I figured out the issue when I floor it. On the accelerator pump the bar holding the ball valve in place had too much clearance. I think I got it but I'll have to try it once this other issue is figured out.



I have a clearance issue with my fan.

Option 1: bolt the fan directly to the water pump pulley. This leaves too much room between it and the radiator in my opinion.

Option 2: put in an electric fan. I've heard pros and cons. I have one with all the wiring. It's a 16" fan. It would have to be offset to clear the water pump pulley but not significantly. Like 2". This would also require me to put the temp switch somewhere. Any ideas there? Into the side of the radiator? Some place on the block?

Option 3: I have a buddy with a lathe. We could turn down the fan spacer from 2-3/8 to about 1-1/2". This would put the fan about 1/2"-3/4" away from the radiator.

I'm leaning towards option 3.

I vote for the electric fan. Less engine power used when going down the road. You may need a more powerful alternator.

I would run a clutch fan.
No hassle, no over working your alternator. Reliable.
Tests have shown a good clutch fan is just like running no fan as far as HP loss.

MBHD

I have a 130a alternator.

...but where do I put the t-stat?

Just read through the build. Lovin it! Sounds like that 250 has some guts. Tom Lowe sells valve covers that have some nice thick flanges that won't warp at all. Got one for my 292. Doesn't have the chevy script, but is tall and big. Thinking on a turbo for mine as well. Good stuff! Watchin the build for sure. TJ

One of the guys at work had a spacer with taps for the thermostat. It looks like this:

[IMG]http://pitstopusa.com/images/F14599212.jpg[?IMG]

but without the O-ring and it has smaller fittings. I can drill them out and put thread it for the thermostat. Plenty of meat on it.

Looks like I'll be going with the electric. I plan on running my main power right off the alternator since the harness has an inline fuse and the alternator is right by the fan. For the relay keyed power I'll tap off the wire I'm using for my electric choke (it's low amperage so I won't be taxing that circuit). I'll mount the relay on the core support and hide the wires in the fender.

Should come out nice and neat and make the engine a bit quieter. Hoping it'll free up a pony or two as well.

This is the easiest, cheapest, and most effective way to do it with what I have in my garage right now.

If it doesn't work I'll see if my buddy can turn down the fan spacer a bit.

An electric or clutch fan will make more hp than the 4 blade stock fan. If it proves out that the electric is not enough to cool it you could add a narrow blade flex fan. The car will be much quieter without the 4 blade fan. Jay 6155

Welp.

Put the new electric fan in, got some of the wiring done, went to take of thermostat housing and broke BOTH bolts.

Now I'm on daddy duty so I won't be able to get back to it until tonight. Started to drill it out but ran out of time. it shouldn't be too hard to finish up now. I have taps to fit this so it shouldn't be too bad.

Also either I need to drill out and tap one of the ports on the spacer or cheat with a closed nipple and an increaser. Might do the latter just to drive it this weekend. I can take it apart and tap it at work next week. Don't have a tap here that fits.

Now you can get that big aluminum thermo housing that MrHotRod6 sells on ebay. lol Dang it looks good! TJ

I think if you add an electric fan/s you should add a shroud to the radiator.

http://www.entropyrad.com/67-69-camaro-dual-fan-radiator.html?gclid=COzuq4-Z0MMCFZJm7AodRHMAWA

I think radiators are designed differently when electric fan are being used. You would not run a 4 row radiator w/an electric ran, I think most radiators that use electric fan are two row. Could be wrong though.
But I would do more research.
It seems just bolting on an electric fan does not always pan out.

MBHD

So far the electric fan seems to be working out.

I let it idle in my garage for a good 30 minutes and no overheating. I don't like the temp sensor right now. I'll pull off the spacer tomorrow night and take it to work where we have about every tap and die under 1". This way it'll be plugged into the spacer where it should be. I might do a second tap the same size for the dash indicator light. I've never had a false high temp reading but better safe than sorry and this solves a design flaw.







Haven't done the filler plate yet but I will and I had to offset the fan to clear the water pulley.

As to a shroud: I don't think it would help in this case. The fan is very close to the radiator. There isn't enough room to have any appreciable amount of re-circulation. It pulls the air right through.

Taking it for a spin right now. Just drove it around the block, though, and the stumble at full throttle is still there.

Honestly that probably wouldn't clear the water pump pulley. We don't have as much room there as the V-8's do. Our engines are longer.

Not saying to buy the one I posted. Just to view the design of it.

Problem when you bolt on a fan as you did, only a portion of the radiator is being used, hence needing a fan shroud where it would pull air through the whole radiator.

You have a newer style radiator so that is probably helping it cool.


MBHD

So I drove it around a bit.

Don't try to do what I did with the temp sensor. Doesn't work. At all. The car almost overheated when I took the family out for dinner. Luckily I had a piece of wire, gum, and paper so I could McGyver at jumper and not blow a head gasket. I think it didn't get too hot because of the massive amount of cooling surface area I have at my disposal now.

Also I got ahold of my neighbor with the lathe. He also has the right sized taps. We'll do both and try the electric fan first. If that doesn't work then on to the mechanical. Should have this solved by noon tomorrow.

He's the same guy with the fauxarri 250. I'll try to get some pics for you guys.

Do you have a water temp gauge? Jay 6155

Your radiator is bigger than stock size?

You had to make new mounts or did you use the stock mounting holes/hardware locations?

MBHD

...not yet...

It's on my to-do list this spring. A three gauge cluster.

about 2 inches wider.

Original just bolted to the core support. I continued the tradition.

2" wide and 2 more cores.

So it's wider than the opening of the core?

Did you open up the hole for more airflow?

MBHD

I don't like the fan not being centered. Must be OCD. By summer l buy dual fans to fix this.

Actually I was looking at that very thing earlier. The old one didn't fill the hole. This one does. Keep 8n mine ever 9ther engine in a Camaro was at least a 327.

Not being centered? This must drive you nutz then LOL



I am thinking about installing a stock flat hood I seen in my neighborhood for sale.
Getting rid of the one thing that makes my Camaro stand out from others.

MBHD

^NNNNOOOOOOO!!!!!!!!!!!!!!!

I thought your car had nice paint and all it's fenders?

Anyway....

I got together with my buddy around the corner who has a mini machine shop in his garage. He built this little car in it:



Yep. That's a 250GT. Sort of. He hand-built it. Based on a 1970's Datsun, has a Nissan VQ35 at 310 ponies, a 6 speed manual, and weighs in at 2400 lbs. It'll do 11 second quarters all day long and actually turn at the end of the track. We took it for a spin so I could get a new thermostat gasket.

So we were going to drill out and tap the spacer to take the sensor but decided instead to drill and tap the other side so the sensor is hidden under the upper radiator hose.



Looks like this from the top:



I'll get some 1/4" brass plugs that look good to dress it up a bit better. This engine needs to be chrome, brass, Chevy red and black. So it's brass plugs and a date with my polisher.

After running for about 10 minutes it the fan came on and did what it was supposed to do.

Next project will be the fill panel followed by a two gauge cluster for temp and oil pressure. In the future I can add a gauge for boost, right?

...and I'm STILL getting too much gas when the cam flips the accelerator pump! I'm starting to think someone drilled out something they shouldn't have drilled out. I just backed the adjustment bolt way out and will try that next just to see if she goes or falls flat. We'll see.



On another note: while doing the drilling and tapping on the spacer I asked if he thought he could do some head work. Turns out he's done just that to three of his own so far. I showed him the lump port video and he said no problem as long as I promised to do a cam at the same time.

...and now it looks like I'll be doing more to the Camaro in the near future... I think after the cam and lumps I'll go get a bottle.

Nope my Camaro is just a pile. I do have a fender though.

You got the boost gauge right, not too sure about adding Nitrous to a cast piston engine, you have to be spot on with just about everything, timing, A/F ratio. If not, say goodbye to those pistons in a flash.

Nitrous is a very violent power adder.

Maybe if you just want to add 25-50 HP of Nitrous, should not be too bad?

Have you changed the accelerator squirter size?
What size is it now?
https://www.youtube.com/watch?v=k-Nx5HEzvlY
As always, a wide band O2 reader will tell you exactly what is going on when you are having this hesitation problem.

MBHD

So I think I'm an idiot.

I've been pretty busy the last 24 hours or so with work so I just got a chance to look at that video above. I think I see where I screwed up on the carb. at 1:24 it shows how to adjust the accelerator pump arm. I was doing it wrong all along. After doing a bit more research I'm almost definitely too lean when I blip the throttle. I went the opposite way than I needed to on the arm. I think my nozzels, etc, are all sized correctly.

I'll give it a shot and try driving it when the weather clears and I have the time.

I used this $55 HHR fan in my Firebird. It stood up to stop and go traffic in southern California on a ~90-95ºF day. Just minor trimming as needed to clear everything.

Can't beat the price, but if I had the option of a two speed fan I'd go that route. A low speed fan setting continuously on during the stop and go traffic probably would of worked just fine as this fan was cycling on and off at regular intervals. It comes on at 205ºF and off at 185ºF, so was very efficient at dropping the engine temp 20ºF when on.

http://www.amazon.com/TYC-621450-Chevrol...eywords=HHR+Fan

If I find mine can't keep up I'll go with that route. The wiring and relays are done so that would be a simple swap and give me a shroud.