ScottyZ28

Here's the problem: Many month's ago I had an overheat during an extemely hot day in dead traffic. So shortly after I had the fans programmed and the vehicle tuned with C.A.T.S....No problem for a while, no overheating for month's after.Everything seemed fine I determined I had not suffered damage, until a few weeks ago I noticed I was losing coolant unexplainably in a short amount of time. I checked for external leaks and could'nt find any, so I didn't think much of it until more signs started popping up out of nowhere: rough idle (checked plug wires many times), hesitation at times, loss of former power, unexplained coolant loss and overheating.

A couple days ago I had a friend come look at it to help determine what the hell was wrong, we noticed a sweet smell like antifreeze coming from the tailpipes and small trails of white smoke as well. I knew what this meant, a couple days prior to this discovery I heard an agressive tapping noise coming from the left side valve cover towards the back, it lasted for a few minutes before it went away. I shrugged it off and drove it into town, and before I looked at the gauges and realised it, I had reached 260 F-ing degrees! I had to go to O'reilly's and put in 2 whole bottles of Prestone Dexcool and some water wetter on top. I got it home inspected the plugs and the fifth plug boot had moisture and a drop of water on the end of it!

I have already ordered a Sealed Power Complete Gasket Kit through SUMMIT for it and plan to change all gaskets and seals I come across on the way to the heads, as well as take the heads to a machine shop to be shaved,etc. Im hoping there's no major damage to them as the vehicle still runs without major malfunction.

I would appreciate any guidance and information, as well as reccommendations of other parts to replace as well.

The vehicle is a 95 z28 with close to 110,000 miles.
Parts I have already replaced include: OEM WP, MSD cap and rotor, MSD wires and MSD coil, Champion plugs, OEM alternator, Thermostat, and thats pretty much it. I will keep updated once I start project (hopefully this weekend at the latest), and hopefully I don't find serious damage. I have used Prestone 50/50 Dexcool ever since I have had it (a little over 10,000 miles), and have just discovered a ton of complaints of severe engine damage due to the stuff that is unsettling because it is Manufacturer reccommended. Never the less I will keep this thread updated once I start. Thanks to all, and sorry for the long post

JooneJune

All the upper gaskets, head bolts, spark plugs, motor oil, and coolant no doubt.

ScottyZ28

Know of a particular spark plug that's best for my application, it's a mostly stock motor as far as I know?

Feenix

autolite 106 as far as plugs. I've had great luck with em.

my1994z28

IMO Champion plugs only belong in Chryslers..I would only use,ACDelco,Ngk,or Autolites in my 94 z28..Keep us updated as you go along..

ScottyZ28

Yeah, I'm going to go with AC,s this time around for sure. I'm about to drain the coolant and oil, and start removing the basics.

ScottyZ28

I'm starting to consider overhauling the whole engine. I can either rebuild it like it is with a top end kit, etc.

Or

Find a complete performance engine ready to install. I haven't decided which option yet, I'm looking at prices for parts and components to rebuild, and don't know of any sources,websites,etc. to find a fully assembled reliable performance motor that I can just drop in. Does anyone have any thoughts or information? Thanks

P.S. I'm looking to get around at least 400 probably more HP when I'm done. The car is going to stay a street car, so I don't want too much but more than the stock LT1 can produce.

ScottyZ28

Found a local performance customs shop that will rebuild/refurbish my engine for $2500, not including boring. I'm really considering doing that so I'll have a fresh LT1 at factory spec, and then throwing on a top-end kit (probably Edelbrock's). I talked to a rep. from Edelbrock and he said the kit will go right on a stock engine not bored and produce 390hp and 390 ft/lb tq! With it bored .30 over it will produce 406hp. The engine might need boring anyway though I don't know yet. I'll probably need a better torque converter too, and I'd like to make sure the transmission can handle the extra power too. The guy I talked to from Edelbrock said to take it to a local transmission shop to have them make a diagnosis. Does anyone know how a shop can do this, does it require some kind of test, can they do it with it in the car or do they have to take it out? Also another top-end kit I can get for my car is from Trick Flow for alot cheaper than Edelbrock's. I prefer Edelbrock but if anyone knows anything about Trick Flows Engine components then that would help too. Both kits come with different parts, Edelbrock's is more expensive but it comes with their $500 intake where Trick Flow's doesn't. Thanks

ScottyZ28

After doing doing some research I think I'm going to go with Trick Flow's. It produces more power in hp and tq, costs alot less, and has more parts that would be a good investment.

bw_hunter

I'm not going to recommend any particular brand but will recommend you do a lot of research on this board. You'll do better with other manufacturers' parts over TF parts......

$2500 to rebuild your engine without boring doesn't sound like a deal to me....look around some more.

I'm not trying to rain on your parade, just suggesting you use other people's trial and error. Keep looking after you find an answer, there is a lot of stuff on here and you need a lot of data to reach a good answer.

ScottyZ28

Update: Found a race shop not far from where I live. I walked in and they had a Edelbrock intake, Performer Lt1 cnc matched alum. heads, Performer-plus camshaft, Accel optispark, and chrome alternator from Jegs. They said it was for a previous customer with a LT corvette that backed out and sold the car. They wanted right under $2,000 with tax for it all. I picked it all up, towed the car up there yesterday and they started working on it late in the day. I bought a new radiator,hoses,clamps,and autolite 106,s for it already so I gave all that to them as well. I came in today and they had the crankshaft,cam,and heads out, ready for me to inspect. They got to take the oil pan off as well by the end of the day. Everything looked great,no sludge,no wear on anything, heads are in great condition( I plan on sending them to Loyd to be fabricated once I get the money up later on), even the pistons. The gaskets had a few tiny cracks/splits in them and #8 cylinder was almost spotless, I dipped my finger in it and I could smell the antifreeze. That was definately the problem. I will post pics I took of everything before&after to my album. So far the work order is as follows:

1.Proform 1.6 Roller Rockers:$200.00
2.ARP head bolt set:$82.95
3.Cloyes billet timing set:$325.00
4.Energy Suspension Transmission Mount:$50.00
5.New antifreeze:$15.00
6.Install heads:$130.00
7.Camshaft Remove&Replace(replace lifters,adjust ignition timing and valves if applicable,as well as R&I oil pan):$695.50
8.New AC Delco lifters:$200.00
9.Professional Product 52mm TB:$220.00
Shop Supplies:$8.76
Some extras I had them do:Paint intake,and valve covers:$cost of paint and $50.00 for intake
All prices are "out the door"
Total as of right now parts&labor:$2,120.73

If I can make it I'll be test driving it this weekend and paying for it next week...

They can also dyno tune it there as well on a dynojet

MachinistOne

I won't use Proform or Professional Products junk even if it's free.

ScottyZ28

I decided on those two beacuse they were more economical for my application,and Loyd Elliot recommended the proform's with a more aggressive set up from him. As far as the TB goes it comes with the air foil design already machined in it,and is polished(it's just a throttle body,seems to me like you're just paying for the name with anything else for the most part)

MachinistOne

When you see incredibly high failure rates of proform rockers in very mild applications (customer supplied of course), you don't ever consider using them on a motor you have to put your name on.

Same goes for anything Professional Products, dampers which fly apart on the dyno, intakes with missing bolt holes, horribly cast runners, and un-parallel flanges, and throttle bodies with improperly drilled passages and binding throttle blades.

No thanks.

ScottyZ28

Thank you for that info, hopefully that doesn't happen to mine when they dyno it,and hopefully it's all covered under warranty seeing as my budget won't really allow for them to take everything apart,fix any damages and new parts. I trust Loyd's judgement though,especially when his package was more aggressive than this one. I do have a few things going for me with the new heads,and condition of everything else. I originally wanted the BBK TB,but decided to go with something less expensive. So we will see how it all turns out, I always welcome other peoples past experience and knowledge too so thanks.