97 Engine Rebuilt...Need Advice

[97GTSTANG]

My 97 has 150Kmiles on it and its losing about 4 quarts of oil every oil change, there is leaking but very minimal, but my coolant reservoir has plenty of oil in it but my oil doesn't have coolant in it. I was thinking of having a mechanic tear the engine down and just rebuild it. What critical parts should be replaced and it is as simple as removing the old parts and replacing the new ones? I have PI heads on the car already, so I was thinking of getting those port and polish also, Do i have to do anything special to the block? better pistons? do they just swap in?

What websites to go to purchase these items for the best value? I will like a bit extra power, i am definitely not looking for any power adders, just motor work.
What about cams, what do you all suggest, the car will be a daily driver, and my budget for parts and labor is $3000. How much will the rebuild part cost approximately?

Thanks for the assistance.

 

[trinity_gt]

Maybe you should look into a shortblock from, say, MMR and freshen your PI heads (check the guides, renew the seals, port cleanup etc...)

Getting a pre-made shortblock from a known source is probably going to yield more satisfactory results. The MMR 400600 is $2499. If you want to add cams, you're going to be pushing your $3000 budget because you'll also want to add new timing hardware (chains, guides, tensioners etc).

 

[fast97gt]

do like i did, if your budget is 3Gs find a low mile pi motor. you can find em round 1000-1500 bucks, cam it headers and tune. youll earn round 300+hp. i paid 750 bucks for my 2005 pi motor out of a crown vic complete from oil pan to intake. the motor runs awesome and im glad to go that insteaf of a rebuild.

 

[97GTSTANG]

wouldnt a rebuilt get me more HP with better pistons and valves for the heads and then the cams?

 

[fast97gt]

only if you used pistons with valve reliefs to except a bigger cam, face it with pi heads on a npi shortblock your cam options are limited. with the pi motor you have a wide variety of cam options and manufacturers. also youll be way above your budget by the time your guy chrges parts and labor. your engine with with pi heads is already 10:1 compression, using better pistions with the releifs may mean a taller piston adding to compression losing the dd benefits. 300-350hp naturaly asp; youll still get good gas mileage and better results then trying to squeeze 400 or so out of it. face unless you got 10Gs youll not get what your looking for. ill see if my buddy has dyno results still from his set-up from his 2002gt with crower custom grind cam, 75mill throttle body, upper intake, long tubes, o/r-x flowmaters and tune. the car dynoed 318hp and 346ft/lbs of torque

 

[97GTSTANG]

So the vote is to look for a pi engine and use my pi heads port and polish and add cams and get it tuned?

Would LT headers make a difference?

I am just worried about used PI engine because not sure if there is anything wrong with it and what if after everything goes on, we find out there is something wrong with the pistons or something?

Thanks again for all the advice...

 

[fast97gt]

i was skeptical too, but i had gotten good with a local salvage yard employee who helps run the place. he let me in on when good buys would come, what im getting at is if they are a yard that is reputible and not in it for the money youll get a ggod buy. mine was out of a 2005 police interceptor, with 84k on the clock for $750. the engines runs like a dream. at idle the engine doesnt even shutter, on initial start up the car roled over maybe 5 times and fired rite up. it clattered for about 3sec till the top end got oil. if they can hear the car run and they make notes on how it does and what kind of damages the car has will help you decide too. my donor was hit hard in the left rear so the fuel safety cut off switch was activated and the car shut down. even one on craigslist or ebay, ebay they have to honor the product and craigslist you mite even hear it run. on initial decision pull the valve covers and inspect the valve trane and use a light to get a good look down the timing chain area. mine was pin clean with minimal wear signs due to a good maintnance schedule. p.s. the guy i deal with carries a 30day waranty hes got an engine there now with less than 70k for like 1200 bucks. i dont know were in va you live but you pm me and ill give you all the info. btw the yard is 10mins drive from hickory nc.

 

[ninjastang125]

only if you used pistons with valve reliefs to except a bigger cam, face it with pi heads on a npi shortblock your cam options are limited. with the pi motor you have a wide variety of cam options and manufacturers.

The ptv problem is on the outer part of the piston, the dish of the piston is not the problem. The only way to run an aggressive in these motors is to get the pistons notched.

 

[fast97gt]

The ptv problem is on the outer part of the piston, the dish of the piston is not the problem. The only way to run an aggressive in these motors is to get the pistons notched.

ok so what do you not get with "pistons WITH valve releifs". he wants to use a better piston, so why pay to have them notched when he can buy them with the releifs, and i said nothing about the dish being a problem

 

[ninjastang125]

I must have misunderstood you i thought you said P.I pistons had vavle reliefs

 

[fast97gt]

yea it gets cofusing with the 2 engines, the npi has taller pistons, where as the pi has shorter pistons to accomidate the the what very little more lift the pi cams have. but once you put the pi heads on a npi motor that has the taller piston (i.e. thats why the npi motor jumps to 10.0:1 compression). so when making your decisions like i did, instead of spending a bunch of money i dont have i opted for the pi and will do cams later. a;so and no i think what he ment by better pistons was he may wanna go forged instead the silicon pistons

 

[Midnight2V]

Both PI and NPI pistons come to .008 below the deck. There is no taller or shorter piston. The NPI piston has an 11cc dish. The PI has a 17 cc dish. That is why when you put PI heads which have a 43cc chamber (NPI is 51cc) on a NPI shortblock the compression jumps to 10.2:1.

 

[fast97gt]

Oops my b I was not thinkin correctly it is the combustion chamber, but on any level u don't have many cam options with a pi converted npi motor.

 

[ninjastang125]

You have just as many cam options. Look at 98cobra he is running npi heads on a mark 8 block with stage 3 cams. I am running pi heads on a mark 8 block with stage 1 cams. I could have went larger but I didn't want to change my valve springs. Any stage 2 cam you need to change the vavle springs other then hitechs. Just like I said before the problem with these car with bigger cams having ptv is the out part of the piston not the dish. The only pistons that you can have that will not have these issue are after market notched pistons.

 

[Midnight2V]

The differences between options for PI and NPI cams has nothing to do with combustion chamber shape or any piston characteristics. The difference is in the distance from the valve retainer to the spring deck in the cylinder head itself. The NPI will only allow for .535 inches of travel, but the spring deck can be machined to allow more travel. This total lift limitation is the only difference that matters. That is why you see nearly every NPI cam having a max of .500 lift while most PI profiles are at least .550. It is the duration and rate of lift that determine if a PTV issue will be present. It has nothing to do with max lift because max lift doesn't occur anywhere close to TDC.

 

[97GTSTANG]

So do you all recommend i just keep my stock block and just clean it up and port and polish my PI heads and add a stage 1 cam with LT headers? Will that add at least 30RWHP/TQ

If i change the valves on the heads, will that net any HP or TQ?