hey walkee and sanders- what kind of mileage are u guys getting??

 

Well Biggreen,

I can only give you the mileage for the engine as it is now - a standard 1977 `400 with
low cr, edelbrock carb, cam, dual plane intake and no other rebuilds.

In the mix and with a light foot I get 18-20 liter per 100 km, that is about 12-13 mpg.

I hope to get less after the rebuild ......

 

Biggreen about ten miles to the gallon.

Danlee, on my dyno results, I used the dual energy cam with the specs I posted and used roller rockers and some head pocket porting. Here's the cam part # on Jegs: 249-CL32-207-3
Ran the numbers again just to double check. 476tq@2500 and 368@4500
It seems like there is some serious power to be unlocked in the heads. Danlee how are the Pantera heads working out for you?

Sanders

 

The Edelbrock published numbers 282/292 advertised duration (@ 0.006") and 204/214 @ 0.050" are correct.

IMO, the very slow closing from 0.050" to 0.006" is the main problem with the Edelbrock #2172 cam. It has far too much overlap (63 degrees!) for an engine with moderate compression (say less than 9.5-10:1), which weakens its low-rpm torque capability, and its relatively short duration @ 0.050" and relatively low lift makes the torque drop off too early for it to be a good high-hp cam.

If you can't plug in the actual numbers for the Edelbrock cam (even as a custom cam?) in Desktop Dyno, you won't see how weak it really is compared to other cams for the 400 engine.

I have seen real dyno runs where the Comp 255DEH and 265DEH both blew away the Edelbrock 2172 in mostly stock 400s. And in a 400 with a little under 9.5:1 static compression ratio, some good head/intake porting, and a good exhaust system, I've seen the Comp 265DEH put out 485 ft-lbs torque and 385 hp on a real dyno.

 

Bubba,

Thanks for the information about that Edelbrock cam. That slow closing and large overlap are real torque killers. Desktop dyno does not allow the selection of ramp rates. It assumes a hydraulic lifter cam will close at a certain rate and its overlap will be based on its duration. So I cannot correctly simulate an Edelbrock #2172 cam. If anyone mentions using it, I will tell them to avoid it like the plague.

 

Sanders,
The difference between your Dyno2K results and mine are due to the different head flow numbers that you and I are using.

My motor with the CHI 3V heads is running strong. I am planning to take it to the track sometime this summer, but it may be after I return from vacation. I bid on a set of Mickey Thompson slicks on Ebay, but didn't win. I will try it with street tires the first time.

 

Danlee, good luck at the track let everyone know what time you pull down. I'm slowly getting my 68 F100 prepped for the track. I'm mostly waiting on funds and parts. I got a 3.70 posi coming sometime this week then I'm going to bite the bullet and get a gearvendors overdrive system.

Sanders

 

O.K. sorry for the delay ...


Danlee,
a bigger intake valve is interesting ! Can I use the 351C intake valve ?
Summit i.e. offers a 2.19 intake valve, will that fit without any other changes
except increasing the intake valve diameter on the head ?

Bubba,
interesting info about my '2172 edelbrock cam ! After the rebuild my 400 should have
between 9.5 - 10 cr, will that fit better to the big overlap of my cam ?

I wanna do this rebuild only once and reach the optimum possible with acceptable
costs. If a 255DEH or 265DEH will give me noticable more power and torque than the
edelbrock I will buy a new cam, of course !!
I don´t want to invest in a roller cam like 260/270HR due to the head machining.

You said the 265DEH will put out 485 ft-lbs and 385 hp, can I reach this also with
the 255DEH ?


Sanders,
what are your experiences with the edelbrock cam - "sounds good with a high compression engine" - does that mean its WORKS also good ?
I don´t feel the idle that bumpy, what was the timing with the edelbrock cam on your
400?

Uhhh, a lot of questions, sorry but I want to understand and choose the best
combination. Here in germany nobody is really into it !

 

That overlap is a mileage killer also as well as a nasty polluter. Good luck with the 9.5:1 compression ratio tho... You may want to back off a little to avoid maintenance and tuning problems.

 

The 351C-4V intake valve is considered by many to be too large and is shrouded by the cylinder wall. The largest Intake valves that are offered in aftermarket heads for Cleveland and Windsor engines are 2.15 inches in diameter. I was told by CHI to cut down my 2.19" stainless steel valves from my 4V Cleveland heads to use them in the CHI heads, rather than opening up the valve seat to accept my valves.

You should be able to use a cam like the 265DEH with 9.5:1 CR due to the 58.5 degree ABDC IVC, but the 255DEH has only 53.5 degree ABDC IVC and 9.5:1 CR will bring it close to detonation.

The 265DEH has 50 degrees overlap vs the 2172 Edelbrock which has 63 degrees overlap. The Edelbrock also has 68 degrees ABDC IVC. I think that the 265DEH is a much better cam for a 400 with 9.5:1 CR than an Edelbrock 2172.

 

Walkee, If you get a chance read the post "351M buildup lessons learned"
The 2172 gave my motor a nice bumpy idle, on a 408(400). It sounded good with the high compression my motor had. I had about 9.5 to 1 CR. The 2172 is really a terd of a cam though. It was degreed right and setup right, I just think a dual energy cam would have been better for that motor. I would avoid the 2172 at all costs. I agree with Danlee, you will get more bang for your buck(or Euro) with the 265DEH.

Overall the 2172 does not work good.

Sanders

 

Regardless of your compression ratio, the problem with the Edelbrock cam is that is neither a good high-rpm power cam nor a good low-rpm torque cam.

It might be good for some sort of weird compromise that I just don't understand the parameters for.

 

The Edelbrock cam seems to be a moderate duration cam with some weird closing ramp. During that closing period (0.050" to 0.006") it can bleed off compresion and cause some reversion. That reversion gives it a bumpy idle, bleeding of compression reduces the VE and the torque. It doesn't have enough lift or duration above 0.050" to allow the cylinder to fill at higher RPM's. This also reduces the VE and horsepower. To make this cam work, you need very high head flows at moderate lifts, and low head flow at very low lifts (<0.050"). This may be a better cam for a 4V Cleveland or maybe a set of Edelbrock Performer heads.

An interesting note is that the Edelbrock #2182 cam for a 351 Windsor has the same specs at 0.050", but less duration at 0.006". WHAT WERE THEY THINKING?

 

I was wondering if the Edelbrock cam was designed to have retarded timing, like the stock cams were in 1978. Somehow allowing it to pass emissons, just a shot in the dark though.

Sanders

 

Maybe it was designed to reduce the compression on high compression 4V Clevelands, yet keep them driveable.