440 street motor

[69 roadrunner]

Guys Iam putting together a 440 for my 69 roadrunner looking for just a good old street motor the block is 30 over I have the small cc heads decked to 76 cc big valves eldbrook mainfold 750 double pumper static comp ratio is 9.7 to one. It is a auto trans with 3.55 gear in rear end. The ? is what do you guys think the car should run in the 1/4 mile. Thanks Steve

 

[Meep-Meep]

Well, I just built a cast piston .030" over 440 with big valve 915 heads, MoPar .455" / 272 deg cam, 10.1:1 CR, M1 intake (just like stock cast iron), 750 AFB, 11" TCI converter and 3.55 gears. All this in a 66 Belvedere recently ran a traction limited best time of 13.38 @ 109 MPH. The MPH is good enough for a low to mid 12 if I can hook it up with better gears. Only thing is I don't have the pump gas to run it in CA so I have to mix a little race gas every fill up. 190 PSI of cylinder pressure will do it every time.

 

[Cranky]

Your pistons must be down in the hole pretty good to only have 9.7 compression with 76cc heads. A 440 with decent breathing/exhaust should be able to run low 14's at least even with a very mild cam. What manifold do you have? Gears? Transmission? Need mo info!

 

[69 roadrunner]

The pistons are down .095 in the hole. Iam running 3.55 gears 727 trans and duel plane manfold elderbrock perfomer series. I went witha .020 head gasket to get comp up it was lower but with the ca. gas being junk cant go much higher on comp. or will have to run race fuel at $7.00 a gallon

 

[Meep-Meep]

My pistons are about .020" in the hole and my chambers are 79.5 CC. I'm also running a steel shim gasket. Yes, the gas here is crap!

By the way, if you live around the SF bay area don't buy gas at that station in Sunol (off HWY 680). They have a pump that says Torco 110 octane but adding 14 gallons of it to my car did nothing! I think it's time to have a little investigation!!

 

[TruBee]

I would appreciate opinions on this setup: http://www.proformanceunlimited.com/specs/440_stroker.htm

 

[Meep-Meep]

Looks like they use good parts but I don't see a published compression ratio or dyno sheet - not to say they don't know it. Probably just have to ask (maybe it's in the video; I didn't watch it).

With all the fancy parts most of the $11K is transferring money from one hand to another. No real magic that I can see. The machine work can be done anywhere so long as the machinist isn't a hack. The warranty seems good and there is a benefit to having it pre-run, cam broke in and tuned when you get it. I guess it depends what the scope of your project is.

If you are better suited to do something other than build an engine then let them build it, but do get the critical data so you know what you have. I'm talking about bearing clearances, compression, cam specs, etc..

 

[Cranky]

It isn't so much of how much static compression you have that dictates your fuel requirements but it's more of how much cylinder pressure you build and your cam will have a lot to do with that. I've had 8-1 engines ping and 11-1 engines that didn't. It has a lot to do with the combination and having good quench. If you have a cam that bleeds off cylinder pressure at low rpm, you can use more static compression. Your power will be down some at low rpm but most high performance engines make the most power from about the mid range on up and once the rpm is up, there's not much time for ping to occur. I also posted an article on quench in the General Tech forum.....which also talks about other things that happen in the combustion process.