My v8 conversion thread, With pics, progress, questions ect!! Options

[Slowpoke]

I haven't read every single post, but, have you checked to make sure the vacum advance and centrifical (spelling) advance in the distributer is working. Cause that's what this is sounding like to me. Try another distributer. (IMG:style_emoticons/default/sad.gif)

[skline]

Ok, well let me pass on some information I got from Renegade the other day when I was talking to Mike over there. I told him about the black car that Joe bought and how the temp goes up when you drop the idle down after running and then it goes back down after a minute or so and when you shut it off the temp goes up, he simply and confidently stated that there was air in the system. He said bleed it again and again till it all comes out. I hope this helps you with the over heating issue.

[Andyrew]

Theres air in the system because of my overflow tank thingy...

I'll get the air out somehow (somehow...)

Slowpoke.. Its a new (read completly new) dizzy. And I plugged the advance off.. last run.

This is a 250hp engine (350 tq).. It might make 200 hp with the advance off... but its currently about 100. That is NOT the problem.

[scruz914]

Driving around its about 185-170..  get home.. shut it off.. and in 2 mins the engine is at 230.... radiator is cool.. so keeping the fan on just doesnt make sense.. but hey, we leave the fan on anyways every time we shut the car off. So I just get even more angry... this happens EVERY TIME. 40 degree increase in temp when the car gets shut off? And I bet when If I start it it will jump RIGHT back down to 190 (like it did last night....)

andrew

Andrew,
An increase in temp is normal when the fluid is not flowing. When you turn the engine off the fluid stops flowing and you will get a very high reading. If you start it right back up the temps will drop. You may want to wait a few minutes before shutting the engine down if you are worried about too high temps. My experience is from a water cooled engine in my VW bus. As soon as I shut the thing off, the temps shot up. If I immediately started the engine back up the temps would drop.

-Jeff

[Andyrew]

Ya, but the water (yes, im running straight water) is poping the pressure cap and filling my overflow tank, then it boils (then spews out..). So dad says we might be running a 50% mix to try and raise the boiling point.

[Andyrew]

Levi When would be a good time to call tomorrow? We'll be workin on the car till about 4pm (I got work then..)

[Andyrew]

Will add some coolant, and water wetter tomorrow...

still doesnt help the engine problem though... lol

Any clues to sleep on?

[dan10101]

Sometimes we just can't see the forest because all the trees get in the way...

Coolant going in tomorrow.

So, if we decide to use Water Wetter instead, how much should be used for effective cooling?

[Andyrew]

Well.... its slow.... past 1/4 throttle it just makes loud "working" noises and doesnt have much "go".....

You know... THAT engine problems...

I fixed the mounting, and the cable... cable? throttle cable oh, no thats fine.

[John2kx]

After reading your entire post again (it's been a while), it sounds like more of a problem with the timing/distributor since you have had the same results using two different carbs. Here are a couple of things I would try.

Are you sure the distributor is installed correctly? I had a mark on harmonic balancer to know when at TDC. You'd have to pull #1 plug to verify your on compression stroke and then ensure dist. rotor is pointing at #1 on cap. A finger in the spark plug hole of #1 while someone is bumping over the engine is the easiest way of determining if your on compression stroke or not.

If this checks out good, you could make small changes to distributor position while out on the road. Just don't fully tighten distributor hold down bolt and make small changes until you see improvement. Mark dist. and intake before you start and make changes 1/8" at a time until you see improvement. Work both sides of your reference mark to make sure you try advance and retarded timing positions. I'd also double check to make sure the plug wires are installed on their right cylinders. A bad set of plug wires could also be the cause and it's not clear to me if these were new or not during your rebuild. A Camaro I once owned ran fine at idle and mid throttle but was a dog when the throttle was at 1/2 or more.......ended up being a worn set of wires.

Your cooling system issue where your temps. are OK while driving but overfilling expansion tank could be better diagnosed if you posted a pic of how this is installed. Might just be a bad radiator cap. 16 lb. is what Renegade recommends with their setup. Your not using theirs, so a change to 18 lb. or so might be worth a try. If your timing is way off, the over filling of expansion tank might just cure itself.

Did you break the cam in correctly? (2000-2500 rpm for 20 minutes the first time engine ran) A friend of mine wiped a few lobes of his cam last year during his break in and suffered from lack of power. I do not know how to check this with engine assembled. Maybe pull the valve covers and rotate engine while viewing rocker arm operation???

It was not clear in your post what fuel pump your using. Your symptoms do sound like this could also be the cause (starvation when demand is high). You should also check sump in fuel tank for build up of sludge and condition of sock/filter. Disconnecting fuel inlet at carb. and routing to some type of collection device while activating fuel pump could give you a indication if some type of restriction is present.

Good luck........I'm sure you'll get this one figured out soon.

John

[dan10101]

Aside from cooling, we're running into the power drag problem...

Here's what we know so far..

The problem: Under moderate to heavy throttle in 2-4 gear the car feels like there is a trailer loaded with a ton of bricks holding the car back.

Under light throttle, the car responds well.

The engine stops very quickly once the idle is turned down or timing is changed. In other words it's tight. Granted it's all new components.

Tried both carbs. Problem is similar with both. A/F is close enough to not cause this problem. 12-13 under full throttle.

Tried some different timing settings, no change.

Possible problems. (brainstorming here so nothing gets ruled out)

1) Binding in the drive axles.
2) Missmatch in the connection from SBC to Transaxle
3) Internal engine problems.
4) Secondaries not opening. (ruled out with changing carbs)
5) Plugged Cat and/or muffler
6) flapper valve on the one exhaust manifold closing somehow forcing all exhaust thru the intake and out the other exhaust.
7) Transaxle failure(dragging) under high torque
8) brakes draggin. (rolls fine so not likely)
9) squating under throttle causing something to drag (like the axle)
10) Distributor to far advanced or retarded
11) Completly mismatched engine components killing all HP.


There must be a couple more I'm missing
Be blunt. We'd just like to solve this so he can start driving the car.

We get to play with it again on Friday. So we'll have some time to think about next steps.


Dan

This was burried quick, so I'll bring it to the top.

The Qjet is on the car now and seems ok. Full throttle gave us a good 4bb Qjet sound like it should. A/F readings were good as mentioned. Which port should the Vaccum advance be connected to? The one I picked was off the back-bottom of the carb, but caused immediate pull on the Vac advance. Possible that the idle is too high?

Redoing the trans mount seems to help. But the trans hub is lower than the wheel hub. Upon acceleration it must be dipping more expecially with 2 people in the car. Not sure how much the axles can be out of square before they start having problems.

[John2kx]

Redoing the trans mount seems to help. But the trans hub is lower than the wheel hub. Upon acceleration it must be dipping more expecially with 2 people in the car. Not sure how much the axles can be out of square before they start having problems.

Dan,

This is how my axles looked with car fully assembled and tires planted on ground. You may be onto something but you mentioned being able to roll the car by hand. Maybe try rolling it with 1-2 people inside.

I could shift my axles side to side at least 1/8" or more while in the air or when planted on ground.

John

[dan10101]

Not running any coolant can and will do much worse things that just lower the boiling point...

We have been running water wetter for protection.
But, now will run to the store for some AntiFreeze.
That was in the plans but we wanted to work out any leaks etc.
Thanks for the reminder some things just get forgotten in the midst of all the hoopla.

[dan10101]

This is how my axles looked with car fully assembled and tires planted on ground.

Our trans sits much lower. Possibly too low.
We're going to have Andrew try without my fat butt in the car to see if it makes a difference.

(anyone have any 180 springs they want to part with? )
I know they aren't that much new, but why not ask.

[dan10101]

BTW.
Thanks a bunch John2kx, Sammy, Levi and everyone else I forgot to mention. It helps having people to bounce ideas off when your up against the wall. (IMG:style_emoticons/default/smilie_pokal.gif)

[Slowpoke]

If you are sure the distributer is working perfectly, cause I've seen new parts not work right or fail. Have you checked or set the advance in the distributer? If it's a mallory it's ajustable. Then, have you checked the cam timing? Sometimes those multi position (-4, 0, +4) degree gear and spockets can get confusing, especially with all the choices. Did the cam follow the specs from the cam card? I'm thinking timing issues from what you are describing.

You can find a ported vaccum for the distributer by looking for a fiting on the carb that has no or little vaccum at idle and vaccum starting when the throttle is opened.

Sorry, can't be of more help.

Peter

[dan10101]

If you are sure the distributer is working perfectly, cause I've seen new parts not work right or fail. Have you checked or set the advance in the distributer? If it's a mallory it's ajustable. Then, have you checked the cam timing? Sometimes those multi position (-4, 0, +4) degree gear and spockets can get confusing, especially with all the choices. Did the cam follow the specs from the cam card? I'm thinking timing issues from what you are describing.

You can find a ported vaccum for the distributer by looking for a fiting on the carb that has no or little vaccum at idle and vaccum starting when the throttle is opened.

Sorry, can't be of more help.

Peter

The Cam went in straight up. No special degree gears.

The distributor Vacuum advance is definatly working. I'll check the mechanical advance. I'm going to see if I can find a better port to plug into. All the digrams I see for that car/carb show some additional port multiplier thingy that the distributor plugs into.

I just wonder if the port I've selected is correct, but since the idle is so high, the carb thinks we're already at part throttle.

Today we added Coolant to the mix, changed the oil and filter, cleaned up the wiring somewhat.

[rick 918-S]

If you are sure the distributer is working perfectly, cause I've seen new parts not work right or fail.  Have you checked or set the advance in the distributer?  If it's a mallory it's ajustable.  Then, have you checked the cam timing?  Sometimes those multi position (-4, 0, +4) degree gear and spockets can get confusing, especially with all the choices.  Did the cam  follow the specs from the cam card?  I'm thinking timing issues from what you are describing.

You can find a ported vaccum for the distributer by looking for a fiting on the carb that has no or little vaccum at idle and vaccum starting when the throttle is opened.

Sorry, can't be of more help.

Peter

The Cam went in straight up. No special degree gears.

The distributor Vacuum advance is definatly working. I'll check the mechanical advance. I'm going to see if I can find a better port to plug into. All the digrams I see for that car/carb show some additional port multiplier thingy that the distributor plugs into.

I just wonder if the port I've selected is correct, but since the idle is so high, the carb thinks we're already at part throttle.

Today we added Coolant to the mix, changed the oil and filter, cleaned up the wiring somewhat.

You need to pickup ported vacum. There should be a port that only sucks under exceleration. The SBC is prone to heating up if the timing is off. Check to see you have the correct harmonic balancer. the later balancer have a built in advance for emissions. Check to see you have the correct dizzy for the motor. I think the same deal applies with emissions stuff.

[rick 918-S]

I didn't hunt through your entire post do you have pictures of your cooling system here? If so what page? I want to see all the connections and the radiator/fan system your using. I may have a few things I can contribute.

[Andyrew]

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