Reusing Pistons for rebuild?? Boost controller?

[frontierguy25]

I have a motor that has been in my car for about 4 years now. 5 of the 6 JE pistons look fine, the other had some thing (spark plug I think) drop in there, the piston still had 150 compression, just made a scratch in the cylinder wall. I've got another piston in great shape the same size as the others that I have. I'm thinking about buying some new piston rings for the pistons and putting them in the stock block that I have.

You guys have any inputs on any precautions I should take?

Also I was thinking about replacing my Turbo XS MBC and getting a Greddy Profec B II. When I called MVP they said that they have been having problems with it going over 23psi, anyone have any experience with it doing this? If so what other boost controller should I go with?

Thanks

 

[Bigdough666]

Im not expert, BUT, I think as long as you have a machine shop mic the pistons and machine the block to fit, you should be fine.

Ive never had luck with an electronic boost controller. The $10 MBC on my Supra works like a champ and has never let me down. Is there a reason for wanting to switch over??

 

[frontierguy25]

I'm going to have them checked out today. I just want to get my car back on the road.

The MBC works fine, but having the internal wastegate the EBC will not creep as much.

 

[jdub]

The block cylinder will need to be checked for roundness and piston-to-wall clearance. If they are round and the wear lip at the top can be removed, you can get away with a cylinder hone...over 4 thou clearance, you will get piston slap with the JE's. Might as well have the block decked for a MHG (30 RA) while you're at it.

You want to check the main clearances as well. The big rod ends will need to be re-sized with the rod bolts torqued to spec...go for a mid spec std rod bearing clearance. The crank will need to be checked for straightness...the journals will need a micro polish at minimum.

 

[frontierguy25]

Oh yeah, the motor I have is stock bore, it will have to be bored to .020 over to fit the JE's. I'm not going to be using the same block again because It needs to be bored over more and I would have to buy .040 over pistons for it. I just want to make sure that the pistons are going to be ok enough to put in this other motor.

 

[jdub]

Get the block magnafluxed for cracks before you spend another penny on it. If you replace the freeze plugs, use Toyota OEM steel plugs.

Pay attention to the piston-to-wall clearance...JE's spec a 6 thou clearance iirc...that is too much and you will get slap. You will need new rings (of course) and deburr the edges/ends.

 

[Bigdough666]

I'm going to have them checked out today. I just want to get my car back on the road.

The MBC works fine, but having the internal wastegate the EBC will not creep as much.

I can imagine man, when my car is down I go crazy. Glad to see you are workin on it though and Im really glad you didnt give up.

Thats weird about the MBC, I dont get any creep from mine. I would just do some research online about the EBC you want to buy and see what some other guys have said about it. Check out different forums and stuff and go from there.

Hope you get it all sorted out soon and get her back on the road.

 

[black89t]

i have the truboost and i love it compared to my old mbc. faster spool, less creep, and way more boost in first/second. plus it saves me gas because i can just turn it off and only run 8lbs. no comparison other than mbc's are cheap.

 

[frontierguy25]

Thanks guys, and Fred, yes I'm keeping her and trying to get her back on the road again in the next two weeks. I sent off my injectors to be flow tested and cleaned, to make sure they are fine. I'm not getting rid of the Boss turbo either, my goal is to just max it out with my system this summer, hoping for close to 500rwhp and some low 11 times.

My wastegate is at 1 bar so 14.7psi so with the boost controller I can't just turn it off, I'm going for a street tune of 18psi and a race tune of 25psi, (race gas of course). But yes with the EBC I will be able to boost faster in 1st and 2nd gear and have full boost a little faster over all.

 

[IJ.]

Get the Pistons Zygloed BEFORE you have the virgin block bored.

 

[frontierguy25]

Get the Pistons Zygloed BEFORE you have the virgin block bored.

What is Zygloed? I want to make sure everything is right this time around. My goal is 500-525rwhp max with race gas. I know that this isn't that much to some of you, but I want to make sure the motor can handle it fine. Low 11's is what I'm after so any help is greatly appreciated.

 

[IJ.]

It's a crack test for Aluminium parts they'll pay close attention to the ring lands.

 

[CyFi6]

I have seen stories and videos about people sandblasting used pistons ( including on horsepower tv) but had read recently that particles can embed themselves in the metal, and ruin your cylinder walls, so just a warning, don't blast them! At least not with sand.