I'm getting close to assembly time, and wanted to run things by you guys one more time. What I have is basically a 428 (a 390 that is now .080 over with a 410/428 crank). I'm running newly rebuilt C8AE-H heads that I have not cc'ed (the books list a volume of 67-69 cc) and that have stock valves in them with hardened seats.

My machinist is recommending some cast Badger pistons with a 1.667" compression height. By my calculations, that will leave a deck clearance of 0.025". Assuming 69 cc chambers and 5 cc for the valve reliefs, along with a Fel-Pro .041" gasket, I'll have a compression ratio of 10.7:1.

That's about a point higher than I was hoping for (I wanted to keep it under 10:1). This will be a toy truck, so the ability to use 87 octane isn't really a must, but I do want to be able to do some towing on hi-test pump gas. I won't be racing it.

Any ideas? Will I be o.k. as is? I was planning on using the Crane 343901 cam (260/272 adv., .501/.533), but now I'm thinking I may want to go a little longer to help keep cylinder pressures down. My truck will have A/C, power steering and power brakes, though, so a decent idle is a must, and it is a truck, so I don't want a motor that dogs it under 2500 rpm.

FYI, its a 2wd '69 F100 with a C6 and (for now) 3.25:1 open rear. I've got a Ebock Performer 390 intake, 625 cfm 4v carb, Pertronix ignition, and Stan's headers. Thanks in advance for your help!

 

Hey Karl, where ya been man!?

To be safe you might want to cc those heads, the book says 67-70cc but I’ve measured bigger.

Glad to see ya around!

Barry

 

Thanks. Work has been kicking my butt for the last month or so, and it's been too darn hot to work in the garage, anyway. Besides, SWMBO has been keeping me busy on other household projects. Now that it's finally cooling off outside, I'm turning my attention back to the truck.

I hope my heads are bigger than 70 cc, 'cause that would only reduce the CR. I am going to have them measured. The high CR might also just be the excuse I need to justify having the chambers polished, valves unshrouded, etc. Any idea how much I can open up the chambers before I run into problems?

 

I got about an extra 6cc out of mine, it's now at 80.5cc I'd block off the exhaust crossovers for a cooler intake, cold air helps with higher CR.

Also the polishing removes sharp edges and that helps too.

 

I had a 428 CJ with the CJ hydrolic cam in it on the streets for years and it was just fine all around. Punching a 390 out that far may create thin cylinder walls and heating issues possibly. Guys around here tried it and it was a roll of the dice how it worked going that far over on a 390. If you want torque at a certain RPM range then consider cam timing changes accordingly. Use a good true roller chain set with 2-4-6 degree cuts in the crank gear. I highly recommend you use an oil pan that has 2 or 3 quart extra capacity as these motors pump a lot of oil upstairs. I allways welded an extra capacity box on the deep sides of my stock pan. One last thing, on the rocker shaft stand where the oil comes thru the head, I used to plug the oil feed hole with a holley carb jet to restrick flow and never had any issues upstairs. Of course I used a high volume oil pump too. Keep the raps below 6500 and it'll live long.

Happy wrenchin

Rob

 

One of the other posters mentioned oil pan capacity. I installed a F600/F700 361/391 oil pan in my 1970 F100 It held 10 Quarts But I had to baffel it so the oil would not splash up to the crank at the rear. Installed the oil pick up from the same engines.Also had a windage tray in mine I had the 428 SCJ. I ran a solid liffter cam 600 lift 330 duration and 116 degrees overlap would idle at 800 rpm. I had this engine also in my 1969 F250 with a camper on it 3.55 gears worked well 18 MPG with camper. With the 4.88 gears emty it ran 13.79 in 1/4 mile. Up here in Edmonton Alberta Canada.I had four speed top loader trans in both trucks.

 

>My machinist is recommending some cast Badger pistons with a
>1.667" compression height.




I'm really sorry I didn't catch this earlier NEVER use badger cast pistons, although I guess they have held up ok so far, I will never use them again because they couldn't even send a matched set to me, when I got them back from my machine shop (I also partially blame them for not telling me before they did the work) they told me they were mismatched and one was a LOT lighter than the rest, with varying amounts of metal being removed all over the bottom of the pistons.

 

I think your right about maybe wanting a little bigger cam to bleed off some pressure at lower rpms. But what is this about the badger pistons ? Are you sure you want a cast pistons at all ? Yeah, I know the 428CJ came from the factory with cast pistons.....but the badgers are not very well thought of. How about a TRW 2303 or 2245 forging ? IF you should have any detonation, the forgings will last longer. I wouldn't put cast pistons in anything but a grocery getter. DF

 

How about a TRW 2303 or 2245 forging ? IF
>you should have any detonation, the forgings will last
>longer. I wouldn't put cast pistons in anything but a
>grocery getter. DF

The problem is finding ANY pistons at all. TRW no longer makes 428 pistons. I checked with a couple of sources. Several said that the 2303 and 2245 weren't "available." Finally, Phil at Flatlander Racing told me that TRW doesn't make them, anymore. In fact, according to him, NOBODY makes 428 standard forged pistons. Ross and a few others stock 428 forged pistons, but in .030 over only -- not standard bore. He told me that if I wanted forged pistons for a standard bore 428, my only option was a custom set for $756. If I was intending to race or thrash my motor, I'd do it. For that kind of money, however, I'll go with the $25 cast pistons in my weekend cruiser. If and when it blows up on me, I'll spend some serious dough to get a Genesis block and build myself a 454 FE, but I'm guessing that the cast pistons will work just fine.

Which leads me back to my original question -- what about the compression ratio? My machinist wants to fly cut the pistons to shorten them a little and bring the compression ratio down from 10.7 to about 9.5. My heads, it turns out, are pretty even at about 68-69 cc. He says that the best way to reduce compression is to cut the pistons down rather than expand the combustion chambers. Any comment?

Incidentally, the cam I think I'm gonna go with is the Crane 343941. It is listed as 272/284 adv, 216/228 @ .050, 112 LSA, .533/.563 lift. Crane recommends it for 8.75 to 10.75:1 compression, 2600-3000 rpm cruise (which is perfect for my gearing), with basic rpm range of 2000-5000. It's a step down in duration and lift from the 343801 that many of you recommended, but its narrower LSA should mean about the same amount of overlap.

 

Went with the 361 oil pan on my 423 (390 but didn't go the 80 over)
390 heads 70cc CJ valves/hardened seats some port work done. But went with JE forged D shaped recess to get my comp down to 9:5:1 still pinged alittle on 91, but MSD anti spark knock is going in this week, should solve that problem..

Agree with the rest on the cast v forged, few buck more now or alot later
.


1QUICK75
75 F150
423 FE
heads reworked/CJ Valves
ATO C6 lowered 1st & 2nd 10" torq/1800 stall gearvendor OD
393 Detroit Locker

 

[updated:LAST EDITED ON 05-Oct-02 AT 01:58 PM (EST)]Hey man, we've got almost the exact same truck! Mine is a '72 with 428 w/headers & 600 edelbrock carb, C-6, 3.25 open rear (for now) F-100. I am planning on building mine up as well, but I am at college in SF right now and my truck is at home in Seattle. But when I get it down here and can start working on it again, we'll have to compare notes

Good Luck!

 

I also have the similar truck mine is 1970 with 72 grill Haakeye50

 

okay all, I asked my boss at work and here is what he said, sealedpower-speedpro puchased TRW. Then, some other firm bought them out. I don't know who the parent company is now. Our catalog says 'sealed power, by speed-pro' on the cover. We recieved a new copy less than 2 weeks ago. It curently lists the forged pistons for 428s as L2245F, mostly flattop with 2&5/8 dia x .145 deep dish, 1.674 tall, sells for 440$ a set. Also an L2303NF, with only a .085 deep dish, all else the same, for 525$ per set. Availablity is 3-4 days from our supplier. 390 pisons come overnight. If I were building Karl's engine, I would use the 2245s. To lower compression from the 10 to 1 these give,I would open the dish up to a 'D' shape or open up the chamber along the spark plug side. I don't like the idea of milling piston tops to lower compression- it opens up the quench to far. Karls engine would already have .067, too much. .030-.045 is best if it is attainable. DF

 

Thanks, DF, I also found them yesterday. I'm a little disappointed with Flatlander Racing, as they are supposed to be Ford experts and they obviously gave me the wrong information.

I am going with the TRW L2245's, which according to Speed-Pro have a 12.5 cc dish. With 68 cc heads and a .041" gasket, my static CR is 10.2:1. I want it down to 9.5:1, which means I need to add about 8 cc to the combustion area. I can cut the pistons, expand the dish, and/or open up the combustion chambers in the heads. What combination of those would you recommend? How much can the dish on the piston be expanded?

 

Karl,I wouldn't cut the tops of the pistons, they're already .017 down the bores. If you have a brigeport mill, or something similar, you could work on the dish in the top of the piston. You need to enlarge the dish, but only under the sparkplug area and not under the quench pad. Its do-able, but kinda of a PITA. An easier option might be to enlarge the combustion chambers. Start by bolting your heads to the block while the block is empty. Spin the engine upsidedown on a stand and look down the bores. You'll see the quench area under the intake port, and some smaller flat spots on either side of the plug.Get something sharp, and scribe a line on the heads, on the outside of the combustion chamber. Then take the heads back off the block. With the heads back off, you will see where you can open up the chambers around the sparkplugs. If you look at some early 60s FE heads, you'll see the 'D' shape chambers you are trying to create. I'm thinking you can get most of what you need around the exhaust valves. You can also widen your chambers to match your 4.13 bores. In order to increase resistance to detonation, you may want to open the chambers more than the 10cc you need, and then switch from the .041 head gaskets to a .017 thick steel shim, your quench will be more effective that way. Can you weld cast iron ? If you can weld closed the heat risers on your exhaust ports, that will help as well. Let us know what you do. DF