?'s about cams, mileage, etc...

[justahoby]

Ok...I think I nailed it this time. 12* initial, fine tuned the idle mix screws again, confirmed that the cam is indeed advanced (though just slightly). Starts great, no pinging, smooth idle. This thing is EXTREMELY sensitive to idle mix and timing settings...I've never seen one this touchy.

I'll run some more mileage tests over the next couple of weeks before installing the headers and new exhaust.

Cool

[englertracing]

Don't use dual exhausts use a single.

[travis]

I've been doing a lot of research and the general consensus is that a single exhaust system actually works better for a combo like mine. I spent some time crawling around under the truck this evening and there really is just no way to make a decent looking dual exhaust system for this thing. Duals would have to be either short, exiting under the rear seat (extended cab, dual tanks), or the drivers side would have to cross over to the passenger side and the duals run side by side. The only other real option would be be running the pipes on the outside of the frame, but I've seen this done and it looks like ****.

I've talked to several muffler shops in this area...seems they all want to retire off of doing my exhaust system I I guess I still haven't adjusted to the dramatically higher cost of living here...

So here's the setup I'm thinking about...shorty headers for the next gen ford trucks (87-96), a Bassani Y-pipe (2 1/4" down pipes, 3" single outlet), and a 3" single exhaust. Everybody rants about how shorties are a waste of time, no scavenging, etc...but nothing about this engine is optimal anyway. This setup I can install myself and should be a pretty dramatic improvement over what I have now.

[wyrmrider]

you're not going to get any scavenge in any case
I have a similar system on my Dakota
Using high flow cats and 3" in 3" out Dynomax Turbo MOTORHOME muffler, HD construction about 36 inches long total with a long core
I also added a resonator between rear wheels and rear bumper area exit

[lada ok]

you're not going to get any scavenge in any case
I have a similar system on my Dakota
Using high flow cats and 3" in 3" out Dynomax Turbo MOTORHOME muffler, HD construction about 36 inches long total with a long core
I also added a resonator between rear wheels and rear bumper area exit

So is your resonator before or after the muffler ?

[wyrmrider]

Cat then Muffler then up and over the axle, resonator, curve to outside right in front of bumper
resonator was a small corvair size turbo muffler but is now straight through- corvair turbo was quieter but I kept hitting things with it as it was vertical

[barnym17]

In your case the shorties will be a big improvement, scavenging with a full exhaust is hard to do , but the decrease in exhaust restriction should pay big dividends.Have you considered using the stock 4180 carb? they are actually quite good for your application .

[travis]

I've got a 4180 series (I think that's what it is anyway)that I yanked off of a 1979 F-150 460 I had years ago. Its a 600 also...very much in need of a rebuild. The calibration probably wouldn't be too far off. Hmmm...something to think about.

The advance curve I have in the distributor now comes in a bit slower than I would like, but with the generic HEI curve kit it was the best I could do and keep a stable idle. I've got 1 light and 1 medium spring...full advance comes in at 3400-3500 rpms. With the 2 lightest springs, full advance at 2500-2600 but the idle is all over the place as it starts advancing at just a hair over idle...like 900-1000 rpms.

I'm looking for a 10 to 12* vacuum can for the HEI...anybody have any part numbers? Both local parts stores looked at me like I had just escaped from the nut hatch

Slightly off topic here, but while I'm on a roll...

The E7 heads have different retainer heights between the intake and exhaust valves. I think the D8's on the old engine are the same way. Like...really short installed height on the exhaust valve. I "thought" I could run a mild performance cam (comp 260 or 268 high energy, 262 isky supercam, etc) as these are all very close to the lift numbers of the factory cam thats in there now, but the factory springs are only rated at 190-210 pounds open at .450" lift...way too weak IMO for a cam with more aggressive lobes than stock, even if the lift numbers are close. No wonder the factory cam is so lazy. All the ford pickup guys say that the stock springs are good for .500" lift...yet nobody posts a good outcome after a cam swap with the stock springs. So what are my options without pulling the heads, if I was to decide to go that route?

[HDBD]

Consider a quadrajet off a similar size motor. If you understand them they can be the best of all worlds after dialed in. Your low vacuum is prone to tip the power circuit often and kill mileage on a traditional Holley especially with that heavy vehicle. If you can find a cam that builds slightly more cylinder pressure with an earlier IVC plus about 112 lsa split overlap single pattern mileage vacuum and idle quality will improve. For what you want the heads are probably adequate assuming they are tight, guide fit and valve seal. If not just a high quality valve job and some pocket work is fine. A decent dual exhaust is needed and a crossover helps too. Headers will build more power but not so much torque in the midrange where you live. The good exhaust after manifolds is the 80% solution and then no added maintenance of headers.
Here is a relevant thread to read
http://www.ford-trucks.com/forums/10655 ... one-3.html

[wyrmrider]

thanks for the truck link- I'll have a peek
but Travis "(comp 260 or 268 high energy, 262 isky supercam, etc"
why put a cam designed for a chevy, and way obsolete, in a FORD (or MOPAR)
you can do both better and less expensive
how about a keeper and/or retainer change for some more installed height?

[HDBD]

http://www.competitionproducts.com/Howa ... E1W5yLF-So
This looks like ballpark to me
It will require retrofit hydraulic rollers though.Not a low cost change. Plus of course the spring pack will need to be able to take the lift.

[Lasher...]

I'm thinking that ISKY cam card is a misprint saying the Supercams are rated @ .020.... the ones I've had experience with were rated @ either .007 or .008 for their hyd cams.

[wyrmrider]

all the Hyd Isky cam series use different "advertised" heights
the Mega series uses a different height for the open and closed sides
Do not have in front of me today but like 007 and 009 or .010
Makes them appear smaller than they are compared to Engle at .008
Comp et all at .006 and especially Crane @.004
all obsolete in any case unless you have a "use a stock or old spring" rule

[F-BIRD'88]

If fuel mileage really matters nothing good is goibg to happen until the cr is corrected.

all the cams you are looking at are way too big for mileage and 8.5:1 cr

[Truckedup]

A lot of discussion about choked up exhaust affecting fuel mileage. Does running down the road at part throttle create that much exhaust volume???