On3 Turbo Build Help

lolls1

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Jul 12, 2014
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First off I'm new to the site as of 5min ago. I have a 95gt. I believe it's and 86 or 87 block. I stripped everything last week. Took it to machine shop it has to be bored .060 over. First question .060 over, wouldn't that be alittle risky with that thin of cylinders being around 500+ hp and with boost? I also have a 351w block but no info on it. All i know it's a non roller block. My budget is around $3000-$4000 including the on3 kit witch is $1600. would I be better off to get a forged rotating assembly and take my chances with the 4.060 302. Or wait, save more money and build the 351w.
 
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There are lots of ways to go. Definitely don't bore a block .060 over. I never go more than .030 over. In my opinion you are better off with a 4 bolt main block with the turbo and a good rotating assembly. There are lots of ways to go. A 351 may not be the best solution due to your budget. Usually it is more expensive to get a 351 in an SN than to run a 4 bolt quality 302 block. Especially if your 351 block is not set up for roller lifters and you have to do an expensive conversion.

Kurt
 
Thanks for the quick response. The problem with the 302 it was already bored .030 over. The shop checked it and almost every cylinder was a different size. And it only had 6000 miles in the last build. So either the last machine shop that did it messed it up or There was a problem internally. I'd much rather use the 351w but I don't want to wait another year to come up with the money
 
I agree with Kurt. I wouldn't post a block that's already bored .060 over. It's just asking for trouble.

Go into local wrecking yard and pick yourself up and Explorer 302. That way you'll get a set of decent heads and intake to go along with the block.
 
I agree with Kurt. I wouldn't post a block that's already bored .060 over. It's just asking for trouble.

Go into local wrecking yard and pick yourself up and Explorer 302. That way you'll get a set of decent heads and intake to go along with the block.

My car is carb. Just getting a blow through. And as far as the heads I have gt40s with a lot of port and polishing work.
 
Ones as good as another. If you plan on pushing the combo beyond 500hp or so, you'd better abandon the 302 block and scour the wrecking yard for 351W, or go with a Dart build.

Speed cost money. How fast you want to go?

My car is carb. Just getting a blow through. And as far as the heads I have gt40s with a lot of port and polishing work.
They make an On3 turbo kit for carbureted Fox's?
 
Just buying the sn95 kit. its for efi but it won't take much to make it work. I'm lookin for low 11s to mid high 10s. iv seen dyno vids of the on3 on stock 302s with cam only around 420hp to 500hp.
As far as the 351 would I be able to use my roller rockers and everything. I think the deck hight is an inch or so higher so I'd have to get different rods fir sure.
 

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The Mexican block thing is bull:poo:. Stock blocks are all about the same. The newer the block the better. Less of a chance you will need a crank turn. I would do a set of forged pistons for the boost and run stock internals for the rest. The heads that came on the Explorer are better than the iron GT40 heads, but they require special headers. It might not be worth the hassle of making them work with the on3 kit. Be careful on the boost. Too much and you will crack it. However I wouldn't jump the gun for a better block, because I would gather that the rest of your drivetrain is not set up for the power a stock block can handle, that's to say you will probably break something else first.

Kurt
 
True. The tranny, diff, and suspension is still stock. should b ok as long as I run street tires. As far as boost I'll probably be around 10psi - 12psi. But we all know how that goes, first time u get beat u start turnin everything up. And I have been doing as much research as possible on the on3 kit. Lots of mixed feelings from people. In my opinion from what iv heard it's a good kit for the price. Will last but dosent hurt to upgrad turbo, bov, wastegate, ect.
 
I've never installed one, but the general idea I get from what I hear and what I read is that it's still a good kit for the price even if you have to do some upgrades. My opinion is that if you don't have the budget to upgrade the chassis and drivetrain, then there is no point in going for the 351 or 4 bolt block. Bolt it on, keep the boost reasonable and just have fun with it.


Kurt
 
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That's kinda what u was leanin towards. I planned on just goin with stock internals gettin rid of my 13.1cr pistons and shooting for 8.1 and leaving everything else alone. And while I play with that be building my 351 on the side so when the 302 fries I'll have something fully built ready to rock
 
I'd just build the 302 right and not worry about the 351 until you have more complete plans. A 351 means cutting up the whole turbo kit and resizing it for a 351. I would run a lower compression forged piston. Stock 9:1 is fine if you can't get a reasonable price on a lower compression piston. Don't get too tied up in it.

Kurt
 
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If you're planning on building a 351W anyway, I wouldn't even bother fooling with the 302. Bolt your heads to it, swap in your HO cam and go. No sense sinking money into a temporary engine.
 
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Do they make an on3 kit for a 351w and an SN? Cheapest way to get a roller 351 is to buy a roller 351 block. I think it's all 94' and newer 351 blocks that are pre-drilled for roller lifters. Older blocks you have to buy those link bar lifters that are $600+.

Kurt
 
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