Pat 69BigBlock

118,000 miles on my matching numbers engine and valves are shot.
Compression is between 120-130 on all cylinders. I'm thinking that I'll probably regret it later if I just address the heads. The engine shows no
signs of ever having been machined. I'm not a mechanic.
What should I do? :confused:

Pat 69BigBlock

P.S. What are my options as far as crate engines if I want to go that route?

69er

I'm no motorhead either but my opinion would be to save your BB engine on a stand in your garage.
With a total rebuild you may lose your numbers on the block although they can be restamped.
However the restamped numbers usually are known to be just that because of background decking marks.
A rebuild is cheaper but I'd pick up a 502 crate motor.





[Modified by 69er, 5:55 PM 12/28/2001]

bence13_33

Personally I think that I would rebuild the entire engine all at once. After 118,000 miles your engine is due for clean-up and rebuild.

As far as crate engines go, what are you looking at (small block or big block). I'm guessing since your car is already a big block that you will want another big block :yesnod:. A ZZ502 is a pretty nice crate engine (but kinda pricey at $6,500). I know if I had the money to buy a crate engine, I would spare no expense by going with a 540 big block...but most people aren't like me. GM HO 454s are nice running engine too.

Pat 69BigBlock

Anyone have the HO 502 crate engine. Jegs has it for 5000$ and change.
:D

69er

Here's a nice one from GM for the mere price of $9850+ tax and delivery:eek:

http://www.sallee-chevrolet.com/Chev...imate_502.html


One of a few 502's available.






[Modified by 69er, 7:12 PM 12/28/2001]

Pat 69BigBlock

Since were on the subject. What is a fair ballpark price for a total rebuild of my 427? I do realize that there is allot of room for variation due to upgraded parts, etc. The machine shop that I've been talking to is familiar with Corvettes and knows the value of a numbers matching engine. We are discussing a totally stock looking engine with some minor internal modifications such as porting the heads and maybe a cam upgrade.
I think the cost would be around 5 grand for the engine not including installation. This does include balancing, blueprinting, dyno and 12/12 warranty.

PRNDL

Pat, I am at the very early stages of thinking about a rebuild also (68 L36, so pretty much same engine you have). My engine runs fine, so the only reason for a rebuild in my case would be to increase power. I won't even consider it if I lose the numbers. It's not that I am a numbers matching nut, and the car is not an NCRS flight car, but the matching numbers have a value and I dont want to lose them. Not sure about the cost, but I will be quizzing 69er and Frank (NJsumpthinorother :) ) about their rebuilds and engine rebuilder.

The most cost effective crate engine alternatives (as Bence suggested) are the GM 502/502 hp and the 454/425 hp engines. The 454 sounds like a plenty powerful engine to me and it is hard to justify the added expense of the 502..... but somehow everybody does!! :) It comes in different degrees of "completeness" and put together-nesss.... ie. one option is a kit - you get all the parts but you have to assemble them, so I am not sure what you get from Jegs for $5k. Most of the 502 complete engine prices I have seen are around $6,500. Check out some of the vendor websites as well as GMperformanceparts website. MJ

As far as forum members, there is ... is it je68 ? He has a red 68 convertible with a 502 crate engine. Must be a few performance upgrades because he has run in the 11s. L88 hood, real nice wheels, I love that car!! :) MJ


[Modified by MNJack, 8:45 PM 12/28/2001]

Flareside

Pat, I just checked out your webpage. Your car is beautiful! Is that a stock color?

Oh, and I also noticed that you're a doctor. Now I know you can afford the Hardcore 632 for $14,995. :lol: :lol: Just teasing... :seeya

Flareside

Pat, I've been through the exact same questions during the last few months. You're 5k price sounds about right, maybe a little high, for a rebuild with dyno tuning. Depends on how extensive the dyno time is.

When I considered spending 4-5k on my existing engine, or a little more on a whole new engine, the choice was easy. Why build one engine when you can have two? This way, I can store my L36 and go crazy with my new Merlin without worrying about grenading a numbers matching block and lowering the value of the car. (I also have illusions of buying a first gen Camaro or Chevelle one day, so I just may have use for two engines!) I'm building the new engine in my spare time when funds permit and all the while I'll be driving the 427.

For the money (and warranty), you simply can't beat the GM crate engines. Take a look at the ZZ502 long block kit. It's basically a roller cam 502 short block and GM aluminum heads for around $5600. If I wasn't building my own engine, that's what I would have bought for sure. You can also get the 502 short block without heads for around $3800, but the compression would be a little high with your current L36 closed chamber heads (just like it is now with your 427.) Be aware that the ZZ502 is based on the new Gen VI block, so your current flywheel won't work with it. With any of these, you'll still have to supply an intake, carb, and ignition (you can use your current ignition and carbs if you choose). (If going with carbs, go Tri-power!) You can also buy a complete ZZ502 from GM with intake, carb, and ignition for around $6500.

Like the other guys said, the HO 502 450HP engine is also a nice piece for the money. 69ttop502 (bill) is the only guy on the forum that I know of that's running it. There is also a GM 454 425HP crate available complete for under $4000!

If you'd like something a little hotter, the Bill Mitchell crates are next in line. A little more money, and a little (or alot!) more power. http://www.theengineshop.com

http://216.34.29.151/serv/engine/buy...104&doSearch=y



[Modified by Flareside, 12:02 AM 12/29/2001]

Detroit Vette

i just restored my 69 427/390 motor. i spent around 4000.00. that didn't include the reassembly of the heads, just the machine work. unfortunatly they decked the block, and removed my stamp.
by the way, this motor is for sale!!!!4000.00 obo.

Pat 69BigBlock

Thanks everyone, car is not an original color. The engine rebuilder told me that the engine numbers would be left intact and that the engine would run better that new. Probably in the 450HP range and torque around 500. We have also discussed a roller cam and rockers for additional cost.
Will the HO 502 or the 454 that you mentioned fit under my existing hood?
:crazy:

Flareside

Pat, my stock L36 is putting out around 300 HP at the flywheel, maybe a little less (don't ask me where Chevy got 390 from :confused:), and it's in good working order with good compression in all the cylinders. It runs the quarter in 14.6 at 96 mph (with normal driving, no aggressive power shifts), which is about right when you read the older articles from the 60's (check Superfast80's site). I certainly don't know more than any good engine builder, but getting 450 from that same engine with it's small valve oval heads, small 250cc intake ports, and small intake and exhaust manifolds will be quite a feat! You're talking about a 50% increase over your current setup. I would be very sceptical of anyone that claims to make 450 from a basically stock L36 with a roller cam. To get 450, you'll need bigger valves and headers at the very least. Next, you'll be pumping 450 HP through a 2-bolt block with cast rods and a cast crank. Probably not a problem, but not exactly the hot setup either. All that said, the warmed over L36 will still be a great street engine as long as you don't go too radical with the cam.

The "complete" crate engines that include an intake and carb will not fit under your stock BB hood, you'd need the L88 hood. That's why I recommended the "long block" ZZ502 kit instead. You can then put one of the carb/manifold combos on it that will fit under your hood.

Intake options that will fit:

-Tripower
-Stock L36 Qjet manifold and carb (with a little porting work.)
-Edelbrock Torker II with a Holley 4 barrel
-LS6 aluminum manifold and Holley 4 barrel. This one requires rectangular port heads.

Pat 69BigBlock

Anyone seen this website.
www.allchevyengines.com
I dont see how their prices can be so low. :eek:

Flareside

I've seen that page a few times, but never heard from anybody that has bought from them. I would be worried about who's putting these things together. Probably not the most experienced mechanics ;)

The 454/425 price seems about right for what you're getting. Remember, the block and most of the internal parts are used. If I bought one, I'd definitely disassemble and inspect it. The block has probably been bored and the crank cut. Personally, I'd rather spend a few hundred more for the brand new GM 454/225, since it comes with a 4 bolt block, forged crank, and forged rods.

Techno

I would talk to your engine builder about the prospect of him building an engine for you. Usually they know everything that is needed to get what you want.
It sounds from your web page that your not interested in maxed out top end numbers, so you could skew the performance towards the low end. With your rear end this would give more torque at the expense of top end power. But for street driving you probably would never see the high end anyway (435hp had higher redlines)
If matching numbers are important to you I would save the engine. Another option is to sell it to someone who needs a matching engine, if this doesn't concern you.
By building an engine complete you could buy anything or buy a base engine and add just the parts that you want. This free for all is where the builder would be useful he could steer you away from contradicting part choices and towards the parts that compliment each other for your needs I think this is the part you need to decide on. What is your base use and requirements. Are there any needs that would modify this goal.

Finaly compare the list of parts and services that the stock engine is going to consume subtract this from a new engine, how much difference is there? A new engine won't need to be bored so take these things into consideration.

68mako

I'd just have the valve job done. Why fix something that's not broke?

Flareside

I guess, as long as you don't mind losing your numbers matching block when it finally breaks :rolleyes: It only adds $5k in value anyway... :lol:


[Modified by Flareside, 1:09 PM 12/29/2001]

Pat 69BigBlock

What about this engine with a low-rise manifold that would fit under my existing hood. www.allchevyengines.com/454-500.htm
Who makes a manifold that would work with this setup? Probably would need a new carb as well and headers,etc. $$$


[Modified by Pat 69BigBlock, 2:41 PM 12/29/2001]

Techno

If the engine is original, the timing chain and sprockets are shot. The cylinders are probably worn and the rings are probably dead. The bearings if they are bad it will be too late. Oil pump?
The problem is you don't know if its broke or not until you take it apart.
If the valves are shot at only 118k what else is?


I would go for some of the upgrades.
I would take the hp and torque curves with a grain of salt. Full torque at 2 grand? Also is the hp in the rpm range you will drive in?


[Modified by Techno, 11:21 PM 12/29/2001]