GT35thconvertable

What is the best piston size for a 4.6 mustang gt with 14 lbs of boost and a accasional 90 shot of nitrous.. I have no idea and need help for I will be ordering the whole rotating assembly shortly...thanks everyone. oh yeah and they are mahley pistons and rods with cobra crank any input??

n/a_threat

size? I'm not quite sure what you asking, but I'd recommend manley forged everything. The rotating assemblies should come with the standard bore and stroke for the 281 - unless you bore your walls or want to get a stroker kit.

04GunGT

DSS

yoteehunter

Well size wize Im not shure....but with that much boost you will want compression around 8.5/1 IMO. As far as Mahley products go. I use there pistons in everything I build. I can testify to there durability I have a very old ford deisel 94 model that is mechanicaly injected. I built it up to make it out run new desiels I used mahley pistons and run 18psi and have a compression ratio of 22.5/1. In the deisel world that is insain (to run that much boost with that high of compression normally you would use 17.5/1). Plus I am running propane injection that will also put a load on the pistons with all the added fuel I run. In gasoline this would be like running 12psi on a motor with 10/1 compression. The pistons I purchased from Mahley are made in the same process that a 4.6 mustang piston would be made. Mahley is a quite company and many of there products are used in indy car and nascar. Just a testiment to there product. Also something you can do to gain about 10 horses is to ceramic coat the top of the piston. I did this in addition to the coating that came on the mahley pistons. Also I used Total seal rings wich is about another 3-6 horse power. The have a near 0 leak down ratio and will hold up to just about anything. If you ceramic coat the pistons you can broaden the horizon esp. with nitrous. I did mine because I have an onboard boost controller and If I am pulling a huge load or racing another truck I will turn on the propane crank up the boost to about 22psi and run water methanol injection. I know it isnt a mustang, but like I said the product is made in the same way a 4.6 piston is processed. If you do the ceramic coating you can be reasured that your pistons will not be the week link, time to start thinking about high quality valves ect..... GOOD LUCK OH also just for giggles my truck will run with a 97 non PI mustang with a manual tranny all stock, but I have to put the truck in 4X4 to get the tracktion to keep up. LOL

yoteehunter

http://www.dps-performance.com/
This is the guy that did my pistons for me as well as other things to help me get the power I wanted. His name is Ken and even though he has a deisel shop he can help with coatings. The ceramic isnt thick enough to mess with your compression. Also the pics he has are of the base coating. In addition to help with the ceramic I polished it with some 3m rubbing compound and a buffer. It looks like crome when this is done and helps the ceramic to serve its purpose of reflecting the heat. The way that you gain power from it, is from the reflection of the heat into the fuel being burnt=better burn=more power. Basicaly you are putting the same coating that the space shuttle uses on its wings, so imagine the heat it will withstand. I never regret doing it, an ontop of Mahleys product I dont think you can go wrong.

GT35thconvertable

hey guys thanks for all the input and more questions got answered that I was going to ask so thanks alot but also what size dish should I get if any...thanks

yoteehunter

I think your car came with 19cc dishes in the piston? I am not for shure.......but at any rate I would try to get them with a smidge more dish just so that you can run that boost up and be safer w/nitrous. The mustangs have something like 9.5/1 compression stock I think. Like I said earlyer the ideal compression for super charging is 8.5/1.......however you could just get the pistons in stock 19cc dish and then use a slightly thicker "Cometic" head gasket (factory head gaskets compress at .039, so like a .065 cometic will get you into the 8something/1 compression range). They make them in almost any thickness and this would bring down the compression and also hold up to boost better than most other headgaskets the way that they are made.