Hello all, I have a couple of questions that maybe someone on here might have a couple of answers for.

I recently picked up a 79 3/4 ton extended cab 4x4 that has a really nice flat bed, great paint, and is in overall very good shape and I picked it up for a great price. The engine, a 400, is running but getting tired and of course not much of a powerhouse. The reason that I got the truck for such a great price is that the tranny's 3rd gear was shot, so for $175 I put a junkyard 435 in it and was good to go.

Mostly the truck is a work truck. I can load up dang near 2 cords of wood on that flatbed and slowly poke my way down the mountain. I live in Montana, so in any direction I drive I have mountain passes to go over. I want the ability to pull a trailer when the need arises, to be able to haul a heavy load up and over mountain passes, and just as an all around work truck. So, with that said, let me throw some ideas out there on the engine build that I'd like to go with.

I'd pretty much planned on building up an engine with Aussie 302 heads, Tim Meyers pistons to go with those heads, a toque cam and the valve train to go with it (one Tim recommended), the Edlebrock intake, and most likely the Holley truck avenger carb, but the carb is still undecided. In other words this is basically the "400 rebuild kit" that Tim Meyer sells on his website. I had spoken with Tim himself explaining what I wanted to do and explained that I wanted something that I could run pump gas in without any detonation. He assured me that this combo would work for what I was wanting to achieve. I had it all planned out, it was a done deal. Then I talked to the machinist in Bozeman who was going to do the work for me. He tried to talk me out of it. Now, he's not just some machinist, but he's got an excellent reputation throughout this area for really knowing his stuff. He was sure that under the conditions presented to him that this engine would suffer from detonation and even just a little detonation would destroy those hyper pistons that Tim has Kieth Black build for him. He said something about the top piston ring being too close to the top of the piston head. I called the tech at Kieth Black. He agreed with my machinist and said that running low-octane fuel and pulling a trailer/hauling a load that I stood a good chance of detonation even with a conservative initial timing.
So, my question for you guys who have built this engine, have you had any problems running low octane fuel and towing/hauling? Do you have any recommendations?

 

I live just down the road, sheridan wyoming. I understand your situation. the quench heads are the best way to go for preventing resistance to detonation. On the top ring on piston the ring gap is a calculated formula from keith black. the pistons with a slight dish in the middle helps push the compression to the middle of cylinder and helps prevent detonation. I'm currently building a 400 just for these application. check out my photos, albums. I'm using a open chamber piston and its even more prone to detonation in OEM application. your piston to valve clearance/quench is the trick. another situation is your carb. i would look into quickfuel carbs. I personally run these carbs and your application around 650cfm with annular boosters. I run my bighorne mountains all the time and pullin elevation is a big deal. Once you get into elevation detonation issues go away. getting air to engine is a big deal and the quick fuel is the way to go. getting air to engine helps keep air temps down going to combustion chamber, detonation prevention. i can't say its a guaranteed 100% but I laying down some money myself for this application. My camshaft is cut my MPGheads in englewood colo. Scott main is a mountain guy and understands our air situation. He can cut you a cam for about the same price as a off the shelf cam. his cam will be cut for your application. the valve opening and closing is the trick to making compression. getting a cam cut just for us mountain trucks is a smart thing. any questions drop a message. sent a private message.

 

issues with 400. upgrade the intake system. get rid of the cam and upgrade and upgrade the exhaust. headers. the factory exhaust manifolds are another detonation situation. headman headers 89360 are a upgrade over manifold. get heat away from exhaust valve. buy a good timing chain factory are junk and have retarded timing. carb mininmum 650cfm and check out quickfuel really good carb. run on several 4wd trucks working trucks and my people love them. i gonna go with a bigger application in my situation but depending on you heads and cam you need around 650 to 700cfm. quick fuel is a holley design but a step above. good luck and give me a call if serious. love it when the fords run well.

 

Do ya think that I'll be able to run this setup with low-grade fuel (it's 85.5 octane here due to the higher elevation) without detonation? I hadn't planned on the headers, but if that's something that can be added into the equation to help prevent the detonation I'll do that. I'll also look into this quickfuel carb.

 

How much money do you want to put into this ?

 

I'm in suburban Denver and use my 400 for pretty much the exact same stuff as you - hauling firewood through the mountains back to my house in the lower elevations.

I don't have the Aussie heads but have the TMI pistons & RV cam & headers & Holley Truck Avenger 670 cfm with the T18 transmission and 4WD.

I don't remember where my base timing is set at right now (I think around 14) but I'm presently running Shell's mid-grade fuel and it's pinging on low-RPM load with an empty bed.

Will most likely retard the timing a bit and play around to get it to stop, the high-octane gas is expensive.

IOW yes, pre-detonation will be something you'll have to deal with.

BTW in the Denver metro area, our fuel grades are generally:

85
87
91

Adjusted for altitude, of course.

 

Right now what I have figured into this is as follows:

$925 for Tim Meyers rebuild kit w/pistons made for aussie heads, timing set, cam, and matched valvetrain components.
$400 Aussie 302 heads (bare)
$1000 engine machine work, long block assembly, and building heads
$500 intake and carb (hopefully...I have not sourced these items yet)
$250 Hedman Hedders

Total: $3,075
Add in an extra $500 for everything that I forgot (plug wires, belts, fluids, shipping costs, etc) and I'm looking at spending right around $3600 from start to finish for an engine producing in the ballpark of 450 ft/lbs of torque and 325 or so ponies.

 

Hey ctubutis, thanks for the reply.

As I mentioned in my first post, the machinist that I plan to use really knows his stuff and is very well known around this area. He told me that those hyper pistons are very sensitive to detonation and that just a small amount of it can cause severe piston damage due to the hardness and therefore brittleness of the hyper pistons.

I do know that one of the features that is built into the pistons designed for the Aussie heads is a quench pad. From what I gather, the top of the piston is designed so that the fuel/air stays in the center of the piston and away from hot valves (I'm probably wrong, but that is how I understand it so far). Do you know if the other pistons that Tim Meyer sells built for the stock heads (the ones that I assume that you are running) are designed with this quench pad feature? Or are those more of a stock piston design with a little more compression?

 

Hey, Partyhound (cool nick BTW)!

I'm really not an expert on TMI's pistons, it's been about 3 years since I rebuilt my engine and my mind has lost track of the details.

My machinist (Rob McQuarie) is also a really knowledgeable guy and builds race car engines at a shop he runs called Blue Oval Performance.

But I don't know what he'd say about the Australian heads and quench and all that, and about the only thing I remember is that TMI pistons are a variant of Keith Black's.

I would give Tim a call if I were you, and perhaps Tim and your builder can talk....

 

Yep, I've spent about an hour on the phone with Tim from TMI (great guy, BTW) over the last few weeks which eventually led to him giving me the number to the guy over at Kieth Black (yes, Keith Black does build the TMI pistons). TMI asked Kieth Black to design a piston to work well with the Aussie heads and this is what they came up with. I spoke with a technician named Glen about some of the specs the local machinist was asking for. I told Glen what I was hoping to get from the pistons/head combination (as far as towing/hauling while running low octane fuel). He told me that he would not expect that combination of piston/head/compression ratio to be able to run reliably while towing/hauling without detonation issues. I then called Tim back and reported what Glen had told me. Tim stood firm in saying that he's got several guys (he's sold over 4,000 of the Aussie pistons) that use the exact setup that I'm wanting to use and they use the setup for what I'm wanting to use mine for and they have no issues with detonation despite running low octane fuel. He asked for my e-mail address and said that he would send me contact info for some of the guys running his setup. I sent him an e-mail with my e-mail address on it and I'm still waiting to hear back from him. So, now I'm in here hoping to hear from guys running this setup on how it works in the application that I want to use it for. I really want to run this setup, but I'm not so sure if I want to go this route if I have to burn premium gas to prevent the engine from blowing a piston. Knowing my luck, someone would borrow my truck not knowing the severe importance of using premium fuel, and would toast the engine for me.

 

There are several things your machinist could do to keep the quench effect with the aussie heads and Tim's pistons but lower your compression ratio down to maybe 9:1 (from the 9.5:1 advertised) if you are really that worried about detonation. You would need to find an additional 6cc’s of volume and according to hp vs compression ratio calculators it wouldn’t have much effect on your total hp output at all. Wallace Racing - Calculate New HP From Change In Compression Ratios Calculator

 

on these pistons the quench is very important. Was just reading on this in a Keith black book. they are saying around .080 is the majic number or less. It speaks of a small shock wave within the cylinder and help move your flame travel around and piston design helps move to center and helps prevent hotspots within cylinder. yes if you rattle/detonate a keith black it will destroy it. but it has some small features built into it to help protect. if you detonate any piston they will all come apart also. Once ran a dome piston in a 351 cleveland and was awesome. the dome move my combustion chamber air around and never had any preigniton issues. 268he comp cam 79 ford 4speed tranny 36" tire. that little cleveland turned the lights on for me on my 4wd combo's. just got kinda lucky and it all worked out my piston to valve was around .065 clearance. Piston to valve clearance is something else you need to know in your application. .080 or less is a good place to start with most pistons. hope this helps and read your keith black tech pages and it speaks of these features in the piston designs. The smarter you build your engine the better the results. talk soon. If you got a good machinist to use see what he's thinking his ideas. 2 heads are better than one in this paticular situation. first thing your doing correct is asking questions and this is a good site to find info. Another site to check into is wallace racing site calculator. Also keith black has a compression ratio calculator and need to know your cam intake valve opening degrees and add like 10 degrees for their site. compression ratio and dynamic ratio stuff. cam greatly effects you compression depening on opening of intake and closing of valves.

 

Wow, I didn't realize that a half a point in compression would only drop about 5 HP. I wonder what that same 0.5 compression loss would do to torque? I suppose that torque loss would be minimal as well. I honestly hadn't considered going this route, but it is something that I'll think about. I was really hoping to find someone that is already running this setup to chime in and say "Don't sweat it, I run this setup with no pinging issues when towing/hauling" but so far no dice.

 

I'll have to get on Kieth Black's website and see what they have to say. I haven't been there yet. I also need to find the specs on the cam that Tim was recommending for my build. He said something about it being an "efficiency" cam, but nothing on the specs. I believe it was made by Comp or Procomp? I suppose that could be important to the dynamic CR. Could just the cam itself bring the static CR of 9.5 down to a 9.0 dynamic CR? And it's the dynamic CR that is truly the important one, right? I'll call Tim later on today when I get a minute and see what he has to say about the specs on the cam he recommended.

Above you said that the piston-to-valve clearance should be .080 or less? I assume that means when the valve is open and the piston is up? In other words closer is better? Why is that?

I'm convinced my machinist is good just from asking around about him. His reputation is "He's very slow, but he's the best around". However, I'm also convinced that a Ford 400 must've been dropped on his toe when he was a kid because he really does not like them. I'm pretty sure that he has not studied up much on what has been done with the 400's over the last several years. Also, he's a one man show so he's pretty back logged with work and has left it up to me to research this build, so I've got to get all the information I can together to get to him. He's told me he won't warranty the work if he doesn't trust the setup and at this point from what I've told him he doesn't like it.

 

tim meyer has some newer cam bearings for these 400's jsut did a set for my 400. I see the potential with the new cam bearings and oil control. need to read up on the 400 cam bearing info with tim meyer. smart feller over their.Getting your quench down really helps on on keep your combustion chamber from being lazy, potential hot spots. Read up on in keith black tech. yes your dynamic compression is very important and lets you kinda know whats really gonna happen with your actual cam. when that valve opens during overlap releases the compression. Been running keith black pistons for several applications and if you follow instructions you will do well. education of a givin product is huge. Another thing I recommend is torque plate the block. help get a better cylinder hone in the end. this simulates you head actually being torqued to the block. All engines move around once torqued to head. the bolts will stress the block around the cylinder and make it out of round. this will help control the oil from bypassing rings during breakin. detonation control of oil which is what ignites during preignition/detonation from hot combustion chamber or hot exhaust valve. Have a photo of a torque plate in my albums is curious. good luck and get educated. talk soon.