six

So I was pulling the oil pan off my motor and found antifreeze in the oil so pulling the short block and was going to send it out for machining the machine shop has done hundreds of mustangs and recommended a long rod 306 option for making high RPM since I am going twin turbo he said that might be better. Anyone have any ideas or know what I should look for when purchasing or rod piston options for this build.

six

Also can anyone recommend cheap pistons are the hypuertech cast pistons OK? I am on a budget ATM.

MRM331

What's a long rod 306? Does he mean some type of stroker?
-jason

six

decided against it for now going to just get some new pistons and rebuild the block for a 306 for now thinking either KB Hypers or DSS forged.

Long rod 306 is 30 overbore with 5.4 rod usualy uses 408 pistons but after doing tons of research not that great a build. Can I get a pistons check though what does everyone like still debating on Hyper cast or cheap forged Speed pro, DSS, Probe soforth also where did some of u build your stroker kits from just trying to get some good advice.

chpmnsws6

I'd go against it unless your using a boss block or better. RPM seems to be a quick way to make twin 2.5's

MRM331

Remember that if you're boring to 306 and adding new pistons you are going to have to have the assembly balanced for another $300 or so. I decided to try my luck and skip this step my first time through and ended up having to completely pull and rebuild the motor.

It may be worth looking into an inexpensive (cast rather than forged) 306 balanced assembly to save you some hassle.

Another option is a 5.0 Explorer bottom end from a yard. I've been pulling GT-40 heads off these for a few years and most still have the cross hatch on the cylinder walls. You could pick up one of those bottom ends and replace the rings and bearings for under $200. Get it with the GT-40 heads and intake attached and you're good to go (I would recommend a used Mustang cam though for $50 or so on ebay).

-Jason

six

http://www.latemodelrestoration.com/...ng-Short-Block
Found this which comes in a 306. Or might just might buy one from local junk yard for 400.
What year explorer motors? 96-97

MRM331

The advantage of the Explorer donor is that you'll have basically all you need to build a very nice 302 with many of the parts Mustang guys swap on later already there. The only thing you'll need to get the power out of the engine is a Mustang or other aftermarket cam.

My last build was a little extream (Forged 331 crank/rods, dome pistons) but the car before that had the following:

Mustang block (identical to Explorer)
Mustang crank (identical to Explorer)
Mustang rods (identical to Explorer)
aftermarket 306 pistons
GT-40 Heads from a 1996 Explorer
GT-40 upper/lower intake from a 1996 Explorer
65mm throttle from a 1996 Explorer
72mm Mass air from a 1996 Explorer
"Design 3" 19lb injectors from a 1996 Explorer
Aftermarket fuel rail (could be replaced with Mustang
1991 Mustang Cam

My point is that if I had just picked an Explorer motor in the first place, and it had not needed to be bored out, I could have had everything I needed less the cam and fuel rails for under $150. Since I went the route I did, I had to source the GT-40 components, which cost me just about as much.

1995-2001 Explorers will have the 5.0 bottom end you need in them. The later ones, however, will have what are called GT-40p heads on them, which are not compatible with Martin's kit headers. Further, the intakes will also not have an internal EGR passage which you'll need if you want to retain the emissions control systems. They also be without a distributor, instead relying on a set of two coil packs (which an be used if you decide to use an aftermarket ECU such as a MegaSquirt). There were a few years in between where the parts got mixed up so you really have to look to see if the parts are the ones you want. Fortunately, it's pretty easy to tell the difference.

Heads: GT-40's will have three vertical cast bars on each end and the plugs come out at an angle, GT-40p's have four cast bars and the plugs come out straight.

Lower Intake: a GT-40 lower intake with the EGR passage will not have a gap in the middle between the first four and the last four intake runners. It will be flush across the mounting surface between it and the upper intake and will have a small (about .5 inch diameter) hole in between the first four and last four intake runners through which EGR gas moves. The later, non-EGR lowers will have a gap in the casting between the sets of runners.

Upper Intake: With the throttle and EGR spacer removed, the surface where the spacer mounts to the intake will have a large intake port with a smaller port under it for the EGR. A non-EGR upper will only have the intake port.

What I'm going to do next time is get a bottom end out of the latest model Explorer I can find in the yard and then pull off the heads and intake and bolt on parts from a earlier, EGR Explorer before I drag it out of the yard.

Hope that helps,
-Jason

fun02se

Jason,
I am very impressed with your Ford knowledge! I am looking for an Explorer engine here in Fl. since reading quite a lot of your posts here and on M.net. Not having much luck yet down here. Is there any year engine you prefer. We don't have emissions yet here in fl. but I am sure we may some day, or if I ever move, so I was thinking that I should build for it. You have emissions in Pa. How do you pass it there? When you "squirt" yours, will you have any problem passing emissions?

DSGcoupe

unless you are a tuning guru, I would stay away from a long rod 306 for FI applications. When you step to a long rod you (alot of times) do end up with a better rod angle, higher rev capability, but at the cost of decreased engine life (if using a stock block). Also, the "long rod" decreases dwell time of the piston at TDC, which can make tuning a B***H with FI. I know this is my first post and I will hit the introductions section, but I think chpmnsws6 can vouch that I have more than a little experience with engine builds of all sorts. ;-) (now including a perkins 4cyl diesel! lol)

six

thanks. and I have abandoned all ideas of doing long rod. I may just purchase a short block built 331 from CHP or DSS. Thank you for all who have posted.

scopx

Not quite correct-
Long rod motors-
Increase time at TDC rather than decrease-
(Keeps piston in compression(read expansive gases) area longer in relation to degrees of crankshaft rotation (read power))
Decreases load on piston as the "yank" from upward to downward motion is less violent-
Decreases rod angle as resulting "side load" on piston-
Alters effective "breathing" capabilities" as downward stroke(suck) on intake cycle is "softened" so care needs to be given to intake runner length and size-
Alters timing requirements-usually less demanding

Does not show additional HP on dyno, just lets engine live a little easier at higher rpm(read longevity)-

Concerning usage of long rod motors-would not consider them cost effective unless used in (long duration) competition events exclusively.
Tom

DSGcoupe

You are correct, it does INCREASE dwell time. ( not sure why I put decreases ) The increase in dwell time at TDC is what makes tuning them with FI and PITA. Great care has to be taken with the machine work and head gasket selection to allow them to live with boost past 1bar. I agree with everything else you wrote. The longevity issue with a stock block though I stand with. RPM's kill SBF's(read stock blocks) after a certain power level. Just not enough material in the valley and other crucial places to hold them together.
Thanks for catching my mistake!
-Lambert

For a good read if your interested(I'm not sure of your knowledge or experience level), check out some of the Data that is out there on F1 motors concerning the changes and effects on Rod/stroke ratios, rod length, intake runner length, etc. Very interesting stuff, at least I think it is.

six

closing info on thread I will build a 331 later finishing project right now.

scopx

Yes, do find the long rod theory very interesting, and have read just about all can find on the net. There is much disagreement, incorrect information, and argument concerning LR theory. But the guys that spend the big bucks (F1 as you state)use this premise in engine design.

Have on hand a 351 W block long rod build in process (at parts collection stage.) And will be using 400 M 6.58 rods vs 5.96 standard. As they are heavy (800>Grams if memory serves) will have to do quite bit of whittling to get them down. They have already been peened and fluxed before I got the set, but will do the fluxing again after cutting them down.

The 351W has plenty of beans for the rotating assembly and significantly larger bearings.

You are exactly right, there is not much on the bottom end of the small block ford. And suspect that in time, we will find the stroker conversions where CIs are way over original block designs (347 vs 221), allow/cause undue stress at the mains webbing in the block if driven hard. Will just have to wait and see how they hold up.

My experience is with older stuff. Perhaps someone with good knowledge of late model blocks could jump in and advise of newer small blocks and their "meatiness" particularly at the mains webbing support areas.

The "earlier" SBF blocks( <75 )supposedly had more meat than the newer models.
(All my accumulated junk is old stuff with the 302 being the newest (75).
In my minute study of crankshaft theory, was surprised at the complexities of achieving "balance" and all of the harmonics generated at various rpm.

I read with some concern about those who like to turn the high rpm just because it will twist. And IMO, sacrificing longevity when upshifting would suffice and be within power band. However, I must confess, it gives me a little buzz to hear it twist.
May I suggest you google "piston speed" An article which has to do with "stroke, piston travel" and maximum safe rpm. If you do not find, I'll look it up and link.

As this thread had run its course prior to my original, hope ADMIN does not consider this a hi-jack.

DSGcoupe

PM Sent scopx