.030 over, too much?

[SaleenGT2001]

the block i have right now is .020 over. i was going to go .030 over to make sure it is clean, but i was talking to the owner of a local speed shop today and he told me nnot to go .030 over. he said the cylinder walls would be too thin. does anyone have any experiance with this? i would just buy a new block but he told me the romeo blocks are not available right now.

 

[mrvax]

Does the walls look damaged? If it's nothing major, why not just hone them. That will clean them up.

 

[SaleenGT2001]

they dont look damaged, but then again i am not a machineist ( i think thats the word)

 

[Stan Weiss]

The best way to know how thick the walls are and how much you can cut them is to have the block sonic tested.

 

[SaleenGT2001]

that sounds expensive. should i just wait for 3-4 months and just buy a new block for $400?

 

[Stan Weiss]

Many shops can do it. Just call and ask how much they want to do it.

 

[Torinalth]

i have heard a lot of companies such as VT and MMR do .030.... i hate to say it but SHM swears by .030... so take it with a grain of salt... if going for lots of boost... maybe not the best idea... moderate boost or NA... go for it.. but i am suspension guy, not engine.

Torinalth

 

[SaleenGT2001]

the engine will see close to 20 psi and possibly nitrous. i will be adding cams and headers so the boost numbers may drop a little but it will be seeing high boost. i guess i will have to wait till ford starts making some new romeo blocks

 

[SaleenGT2001]

hey torinalth, you're right down the road from me. and DAMN your car is tore up! maybe i'll see you around sometime if you ever get it running again.

 

[Gearbanger 101]

I personally don't like the idea of any more than a .020 bore on a modular engine. If the machinest thinks it will clean up with that bore, then go ahead and do it. Why bother buying a new block if you don't have to?

 

[SaleenGT2001]

my block is already .020 over, the pistons taht came out of it were tore up due to detonation. the walls look good but there is no way to tell if they are without taking it to a shop. i want to use the block i have but i'm not sure if it is any good. i dont want to build a $3000 engine and have something go wrong and have to pull it back out anytime in the near future.


anyone have a romeo block they dont need?

 

[Torinalth]

with that kind of boost and nitrous I would get a new block personally... take the machine shop out of the equasion for error.... however, ask the shop if they can ensure a smooth line and constant geometry with just honing it... a lot of times the block (iron) will be fine even if the pistons/rods go to hell.

also the cardomain is ASS old... its running just fine now and has some nice suspension goodies too if you eer wanna hookup and talk shoot me an Email or PM me.

Torinalth

 

[SaleenGT2001]

i may see if the block is still good.

this is what the pistons looked like that came out. only 2 were bad
http://www.modularpowerhouse.com/forums/showthread.php?t=38801
pics are at the top

 

[Stan Weiss]

With the power adders you want you should have a new block sonic tested. It does not take much core shift for the new block to have a thinner wall.

 

[Gearbanger 101]

my block is already .020 over, the pistons taht came out of it were tore up due to detonation. the walls look good but there is no way to tell if they are without taking it to a shop. i want to use the block i have but i'm not sure if it is any good. i dont want to build a $3000 engine and have something go wrong and have to pull it back out anytime in the near future.

Ahhh, I see. I misinterpreted your first post. It sound as though this was your first overbore and that you'd just cut it .020 from the wall. You made no mention of a previous damaged rebuild in the initial post. Still though....if you're unable to detect any damage by visually inspecting it, you probably don't need to have it bored again. A fresh hone would probably suffice. I'd be more worried about hairline cracks making themselves apparent due to violent nature of the failure. If your machinist is at all competent, he should be able to tell if the block is salvageable.

 

[LaserRed01GT]

You need to have the block at least magnafluxed and hot tanked. If you are only going .030" over you might not need to have it sonic checked, but it's not that expensive. Most machine shops will have a sonic tester. It's just a small portable hand held device with a little "probe" that you place down each cylinder. They shouldn't charge you more than $75-$100 for a complete sonic check.

The most important areas to check are the thrust sides of the cylinder walls and what's called the pin sides (front and back) of the cylinder walls. Our 4.6 2V blocks have a 3.937" center to center bore spacing. If you go .030 over that will give you a total bore diameter of 3.582". That should leave you roughly .355" on the pin sides or in between cylinders. That is more than enough. On the iron blocks you can safely go as low as .250" on the thrust sides and .200" on the pin side.

 

[SaleenGT2001]

well i found a new 4.6 iron block for $450. i should have it next week. now i can run a std bore piston and dont have to worry about anything.


anyone need an extra block? i have no use for the other one now.