how long will a build block last under boost?

Dan_Soprano said:

Alot of it will have to do with the tune and your driving style. Get a good dead on tune, and keep the RPM's down, she should live a LONG life!

Click to expand...

Dan_Sporano, or anyone else,

Please tell me how you know if you get a "dead on" tune? In a few days I am getting my 99 blown GT dyno-tuned. It has a built engine and has about 8k miles on it since. I'd love to get a dead on tune, but I know nothing, so I guess I will depend on the shop.

Thank you,
Brent C

ADRENLN said:

im just looking for an average time, mile wise. if it were like a built engine from mph or vt and you were running a blower with about 10 -12 psi of boost. what do u guys think, how many mikes?

somthing else to think about, would it last longer under a kb or a novi at the same psi? or would it be the same

one more, how long do blowers themselves last (miles wise) under boost before they blow out?

Click to expand...

ADRENLN said:

...many that already have this can just tell me how many miles you have so far. i thought the point of the built engine was so you can rev it high with no worries???? the centri doesnt start to make power till high rpm. i just want the strongest engine i can get that will stand up to 112 psi and some higher rpm driving and last some good long miles also. is there a motor like this or what?

Click to expand...

If your engine is healthy you don't need a built block to run 12psi on a centri. A built block allows you to run more rpms safely, and will hold up under more HP than a stock longlock at the same rpms.

Running 12 psi on a centri or 9-10 psi on a KB, with an intercooler and safe tune would be fine on the stock longblock. To be safest, shift points should be no higher than about 6300 because the stock rods are vulnerable at high rpms. For the longest I was shifting at 6500 with 380 rwhp. Some tend to think that intercoolers are not worth the expense, but I've seen enough casualties that could have been prevented if an I/C had been in place. Some of the owners of these broken engines were well versed on tuning parameters, and the dangers of detonation, but somehow thought they would be safe. A built block will also break under detonation, it just takes longer.

BTW, it is incorrect to directly compare psi on a KB to psi on a Novi (or other centrifugal S/C). The KB pushes more air at a given psi, but that results in more heat. The highest psi a KB can run on pump gas is lower than the highest psi that a centrifugal can run on pump gas.

I've been running a Vortech on a stock shortblock for over 4 years and for a total of just under 40,000 miles blown (total miles 46,600+). The 12 psi pulley has been on for somewhere near 3 years with an intercooler. As far as my driving, if I could do it all over again I wouldn't be so abusive . The reason it's held together this long is that the tuning leaves a margin for error against detonation. Detonation is what kills most of the engines we end up reading about. I'm now at 416 rwhp (equivalent to 438 rwhp on a manual car). There are others such as a guy at Corral.Net that has been racing for over 4 years on a Vorteched stock longblock, now with 434 rwhp at 14psi. There are 2 other 2v 99+ GTs confirmed to have run 500+ sae rwhp on stock shortblocks. One was a magazine project car and the other is owned by a member of one of these forums (I believe the Corral).

I've read testimonies from owners with 80 to over 100k miles on the same S/C. Of course blowers can be abused (overspun etc.) or not maintained properly which could cause them to fail prematurely.

registered said:

..Please tell me how you know if you get a "dead on" tune? In a few days I am getting my 99 blown GT dyno-tuned. It has a built engine and has about 8k miles on it since. I'd love to get a dead on tune, but I know nothing, so I guess I will depend on the shop...

Click to expand...

Your tune should be such that it leaves a margin for error. You need a good air/fuel ratio AND safe amount of timing advance. One big problem I've seen over the years, is that even some experienced tuners are too agressive with timing advance. One degree off might bring you a bit more power but that can be enough to break your engine (via detonation). How accurate the tune is depends on the specifics of your setup.

Blown00GTAuto said:

Your tune should be such that it leaves a margin for error. You need a good air/fuel ratio AND safe amount of timing advance. One big problem I've seen over the years, is that even some experienced tuners are too agressive with timing advance. One degree off might bring you a bit more power but that can be enough to break your engine (via detonation). How accurate the tune is depends on the specifics of your setup.

Click to expand...

Thank you!