Any Ideas?

[260Alpine]

Dan, most performance cams I have, had idled best at around 900-1000 RPM. Try advancing initial timing. It will speed up idle even more but you should be able to slow it down with the carb idle screw. Readjust mixture screws also. Some have drilled small holes in throttle blades to help. Also Holley has a secondary stop screw that may be stopping the secondary throttle blades from closing all the way.

 

[MikeH]

Mike, In my experience you help low end by advancing the cam and top end by retarding. Usually 4 degrees moves the power band up or down around 500 Rpm. 290 advertised duration will be approximately 240 at .050 lift. The Buick 350 stroker in Chris's MGB had 4 degrees advance ground in and he advanced it another 4 degrees thinking it would help idle and low end. It did, too much. That cam was 290/300 advertised and around .500 lift. Peak power was at 4900 RPM. Now he has retarded the cam to 4 degrees retarded. Hasn't been dynoed yet but he says a rougher, lopier idle and pulls like a freight train up to 6000 RPM redline.

Don't mean to hijack the thread, just trying to wrap my head around this.
So does what Jose said in the 2.9 valve thread match the delta-cams Jose grind? Jose, if your watching????

 

[DanR]

Very busy today....

ADvanced timing by ear Idle was better at around 12-15 hundred.

Took to the road and as usual it ran very good from 2500 up

If I keep the RPM at or above the 2500 range it pulls good and throttle response is quick.

After it warmed up for about 10 minutes and crusing at 2500 in 4th gear I accelerated up to about 55 hundred and held there for a few seconds, went to 5th and drove for more than 10 miles enjoying the power curve.

As I came to a red light gearing down cautiously and carefully not jerking down the idle slowly went to about 25 hundred then 2000 where it stayed for the duration of the light. Upon returning back to the house I slowed down for a left turn and the idle went below the 1250 and died. Caught the engine up with the clutch while still rolling and it hesitated to run, it did however fire up and did it's thing back to my driveway then died again.....

Will review all you guys comments again tomorrow,

DanR

 

[Toyanvil]

I have not read all of this, so sorry if someone all ready suggested this. Have you tried hooking up a vacuum gauge to watch while driving?

 

[DanR]

Good Idea! Thanks toyanvil.

DanR

 

[Mike Armstrong]

Sorry Dan, I didn't see a tach reading. I don't remember either engine slowly chugging along at idle but I would bet neither one was above 1000rpm (from what I remember).

 

[todd reid]

Dan,
I have been following this thread with interest, but haven't had anything to contribute.

A couple of observations:
1. Earlier in the tread (page 3?) you state your compression is 8.5 to 1. A couple pages back (page 9?) Jim states you should have a minimum of 9.0 to 1 for a cam of this duration. My thought is that Jose has come up with a recipe that works, but perhaps you have inadvertently missed an ingredient?

2. Have you verified the accuracy of your idle rpms with something other than your car's tach? Perhaps your tach is off and the situation isn't as bad as it seems?

Good Luck! Keep reminding yourself "Old Cars are fun!"

 

[260Alpine]

Dan, You said you drove it for months with no issues. Did you just install the Jose grind cam? Something changed so you have to retrace your steps. Do you have any more room on the idle adjusting screw to slow down idle? Adjust mixture screws? Connect manifold vacuum to distributor instead of ported and do what Mike Armstrong did to limit vacuum and centrifugal advance? Todd, Jose milled .030 off the heads to get over 9 to 1 compression.

 

[DanR]

Dan, You said you drove it for months with no issues. Did you just install the Jose grind cam? Something changed so you have to retrace your steps. Do you have any more room on the idle adjusting screw to slow down idle? Adjust mixture screws? Connect manifold vacuum to distributor instead of ported and do what Mike Armstrong did to limit vacuum and centrifugal advance? Todd, Jose milled .030 off the heads to get over 9 to 1 compression.

Jim, During my driving time ( a few months) it has been mostly on the open road. Always had the idle situation, just played it till I decided to get it fixed.

The cam was ordered as a Jose grind (without any other request for anything special) from Delta several years ago and installed as directed.

I have additional room to set idle screw lower! But, If I do, it dies quicker.

Remember I have had 3 brand new Holley 390's on this engine in the last couple months, adjusted as per instructions from Holley AND using the Pruitt Book.

I will go back over the Adjust mixture screws and I will also Connect manifold vacuum to distributor instead of ported as you suggest next week.

I haven't gotten to M Armstrong's suggestion ,to limit vacuum and centrifugal advance yet, Will attempt that also!

As for Todd, Jose milled .030 off the heads to get over 9 to 1 compression. I did not mill the heads at .030..... Read a post from JOSE that said 8.5 to 1 was good enough for this cam. Have it in my archives somewhere.

 

[DanR]

Dan,
I have been following this thread with interest, but haven't had anything to contribute.

A couple of observations:
1. Earlier in the tread (page 3?) you state your compression is 8.5 to 1. A couple pages back (page 9?) Jim states you should have a minimum of 9.0 to 1 for a cam of this duration. My thought is that Jose has come up with a recipe that works, but perhaps you have inadvertently missed an ingredient?

2. Have you verified the accuracy of your idle rpms with something other than your car's tach? Perhaps your tach is off and the situation isn't as bad as it seems?

Good Luck! Keep reminding yourself "Old Cars are fun!"

Thanks for the good comments Todd. I have a post from jose that the 8'5 to 1 works great with the cam he specified, which I purchased.

The ingredient missing is what I'm searching for......And not my Tach it was just recently done by Tom H for the V6. My Buddy helping me has confirmed the TACH is right on.

DanR

 

[260Alpine]

Dan, Reason I asked about the idle screw was the throttle blades may be open enough to cover the idle air transfer slot. Plus if you try manifold vacuum for the distributor the idle speed will pick up more and you will have to slow it back down. With engine warmed up adjust mixture screws out 2 turns to start and turn slowly in until rpm's start to drop, and then open 1/2 turn. I actually like manifold vacuum better for advance. It helps idle if you have a hot cam, seems to run cooler and better mileage under low load cruise. The trick is to limit it to 8 degrees. With vacuum line plugged set initial at 12-14 and limit mechanical advance to 20. Advance should be all in by 2500 rpm. Mikes older thread on his computer control carb explains how to limit the vacuum and mechanical advance.

 

[260Alpine]

Dan, I'm thinking if none of this works you should look at the timing gear set up. They are not aligned like most, dot to dot centered but to the left.
You maybe off a few teeth.

 

[DanR]

Jim, I found this: http://www.romac.com.au/Factory_Timing_Marks.pdf
goto page three fr the 171 V6....the dot marks are in alignment, like every Shop manual (i have three on the V6 FOrd).

This is the way mine are set up.

The PIC you posted is an interesting one with the dots "off set". Is this for somesort of advance timing?

The Web Site above also has Off set Timing gears that perhaps do the same thing.

The Rep from Delta Cams suggest some sort of off set (?)

It's above my head.

My car ran a bit better yesterday with the timing advanced more (by ear). Will do some more playing with the timing this coming week.

Sure hate to pull the timing cover again just yet. I will have to remove a lot of stuff again. Alternator, A/C unit, Fan shroud, Radiator w/hoses, Fan, & A/C Condenser before getting started!

How do you determine where the dots need to be? Degrees advance?

Jim can you send me the PIC of the Gears you posted with the Off set (without" the black ink? I'd like to see a better spot of the "DOTs"... Thanks,

DanR

 

[Bill Blue]

If advancing timing makes it run better, I have to wonder if you have used the piston stop method to determine TDC. I think that is the only way to determine TDC, even with the heads off. Better than indicating the piston top.

Bill

 

[DanR]

Bill, To find TDC in the 2.8 V6 Cologne is a bit difficult going through the spark plug hole because of the angle. A prior suggestion of someone sticking a finger in the hole was not quite a positive in locating TDC of the piston in this case due to only one or a few degrees off.

In my car with the A/C Compressor in the way it is even worse.

I could and may even removed the bolts holding it in place, But, after fooling around with a straw and several other thin objects, I came upon an Idea to take out the center (porcelain & metal contact) of a used spark plug in order to get a "fixed" & steady position for something to probe the inner chamber for the TDC (position of the piston).

I came up with a plastic straw inserted in the old spark plug hole, then found that a wooden dowel cut to about 4 inches in length fit perfectly.

Using one of my spare engine blocks & an old head bolted together, I played around until I could mark the dowel where TDC of the piston would be, marked it, then went to my '67 Commodore Blue V6 and found TDC with the piston in the upmost position ( I think).

I think I have it located but not positive. Hopefully my buddy will be here tomorrow or next day and confirm.

 

[Tom H]

Hey, I'm not a V6 guy, but I am puzzled about Jim Nichols drawing. I don't think it shows a different gear alignment. Looking at the dwg, if you simply rotate the lower gear clockwise, while maintaining mesh, once the dots are aligned with the gear centers, they will both still be aligned with each other, as is common. Now this dwg may be intended to indicate that TDC occurs at this odd point, but that has nothing to do with gear tooth alignment. Or maybe this was part of an April Fools joke.

Tom

 

[Bill Blue]

Dan, the piston stop method is similar to what you did. Make up something that will screw into the spark plug hole, and is long enough to contact the piston well before TDC. Insert the piston stop and rotate the engine until it is against the stop. Mark that position. Rotate the engine backwards until the piston once again is against the stop. Mark that location. TDC is the exact center between the two marks. No guessing or estimating involved.

I have made these out of old spark plugs. If you wish, I can make one for you. would need to know the plug size and approximate length of the stop as measured beyond he spark plug.

Bill

 

[260Alpine]

Dan, I've never been inside a 2.8 V6 either, but have done a lot of work external on my son's Ranger pickup. That picture was for 79-83 Ford Mustang and Mercury Capri. Was the first one that came up for search for Ford 2.8 V6 timing gear marks. That is the only pic I have. I had heard around 1980 the Fox Mustang went to the 200 straight six, don't know about the Capri but I know the 200 straight six has a chain.Your spare motor has timing gears you could check? Like Tom says maybe the gears are rotated slightly for TDC? When you establish top dead center the lifters should be on base circle of cam and rockers not pushing on valves or your timing is off.

 

[Oldskool979]

Dan-

I did a rebuild on my 76 Capri 2.8 years ago and just checked my 1977 MOTOR Auto Repair Manual to be sure. The dots on the timing gears are shown to be in exact alignment on the bolt centerlines. Mine ran and idled fine after. Bill Blue's positive stop method for TDC is a great start to evaluate the initial and overall timing (initial + mech adv + vac adv). I have seen some TDC markings that were 5 degrees off.

Oldskool979

 

[260Alpine]

Dan, Here is the thread the pic came from:

http://torquespecs.tripod.com/mustang_capri_1979-93_v6-2_8.htm