staticki

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timd38

Your screwed pretty bad. You need to have the head gone through and a new piston, in my opinion.

Good reason to buy a new forged motor!

I guess you won't be at the Optima Ultimate Street Car event at the Autobahn on Saturday.

dgrant3830

I'm trying to understand how the valve managed to hit the piston in the first place, assuming you had the correct length pushrod? Did you pull the lifter out to see if anything is wrong with it? The piston has to be replaced...you need to see the rod bearing when you get it out. Could be some crankshaft damage too if that bearing is done.

staticki

I was using 7.4 pushrods. Still trying to figure out how the heck it happened.

taken19

What were the circumstances when the noise started? Missed shift, high rpm run, etc. Did you measure PTV clearance when you installed the cam? If you list the cam specs, others may be able to chime in with clearances. I would say that you are out a valve, spring and possible pushrods at a minimum. The piston and bearing could be in question, but I bet it would snap off the head of the valve before it did major damage to the bottom end. The thing I see that doesn't look good is that you have 100% contact around the entire circumference of the valve head as proven by the complete circle on the piston head.

Search around and ask some of the seasoned vets on this forum what your options are.

Kenny94945

Not to screwed.... block is still whole.

First step - You need to find out why this happened.

Maybe remove the engine from the car for convenience and efficiency. Inspecting and replacing parts will be easy.

AORoads

just asking questions, but one piston replaced only? also, what effect does no tune at same time as cam install have?

TMyers

Looks like the valve siezed in the guide.

staticki

dgrant - I haven't had a chance to pull out the valve yet since I no longer have the tool to take the springs out.

taken - normal driving. Starting around 3500 rpm in 3rd gear cruising down the road. The cam is a Englandgreen Mayhem 2 cam (they don't list the specs anywhere).

kenny - that was the plan to take the entire engine out. I am going to need to do this anyway to replace the piston that was damaged.

aoroads - my thoughts exactly. No reason to replace the whole engine as the block is still good.


My thoughts are to pull the engine and get a stroker crank and piston set up. How hard would this be to do in a garage for someone with decent experience? I am guessing it will be pretty difficult since I will need to bore out the cylinder heads to accommodate the stroker? I figure since I'm opening the entire engine up anyway I might as well put better parts in it--more so since the engine had 70k on the clock. Any recommendations on a kit?

Still unsure what to do with the heads. Would it be possible to put LS7 heads onto a LS2? I might not be able to budget in a set of AFR's, but might be able to swing some ported LS3 or LS7 heads--or would I be better off just going with a ported set of LS2's? I seen Livernois sells some for $1k.

DSOMC6

If it were me, with 80k miles on the odo, I'd send the heads out to WCCH and have them rebuilt. Then rebuild the bottom end as well. Otherwise you may end up spending a lot more $$ in the not so distant future.

staticki

Bottom end will be rebuild with a stroker kit--might as well do the whole bottom end as mentioned because of the miles.

What would need to be rebuilt in the heads? They currently have patriot dual valve springs and titanium retainers that have less then 50 miles on them. Only item in there that would be old are the valves.

TMyers

You either have a siezed or bent valve. Depending on the damage the heads may not even be usable but that is unlikely. New valves and guides at a minimum and since you are there might as well have them ported.

Vito.A

Actually, I think you are very lucky. If that exhaust valve head had broken off it would have broken up the piston which would have left the rod free to trash the block.

The easy fix would be to replace that one exhaust valve, and retainer. Did the spring break or the keepers come loose or did the valve stick in the guide?
You can do a leakdown test by putting the opposite head on that side and the turn the piston to TDC.
It appears the piston is OK, but I would clean it up and use some dye-chem on it looking for cracks.

You need to check piston to valve clearance!!!!

If you want to go through this motor, replace the valve guides with bronze guides and replace all the valves with a quality 1-piece valve, replace the pistons with forged coated pistons, and balance it.

If you are going to install a stroker kit, the heads need to be gone through and all the valve guides replaced as well as the OEM valves. I would just send the heads to WCCH and they will do it all. You mentioned boring out the cylinder heads? That is not required. If the new pistons are oversize, the block will need to be bored to fit the new pistons.
If there is any wear in the bores or a ridge at the top, the block will need boring and new oversize pistons. You can take the bare block and new pistons to a machine shop and they can take care of it. Replace the timing chain, check all the geometry/pushrod lengths, and replace the rod bolts with ARP. Of course replace rings and bearings and use some quality fasteners for the heads. All of this is doable in your garage and some machine shop help.

Best of luck!

staticki

Thanks for the info. Spring held together and retainer keepers are still in place. It looks like the valve is stuck in the guide, but will not know for sure until I can get the spring off.

This is the kit I will be more than likely going with.
403NA LSX Rotating Assembly 11.7 w/62cc
-Callies Compstar4.000 Forged 4340
-Crank w/24x Reluctor
-Eagle 6.125 LS1 3D Forged H-beam
-Rods w/ARP2000 bolts
-Diamond Forged Pistons & Rings
-Clevite Main and Rod bearings

Will require any modification to the block?

deadcafe

403?? What is the difference between that and the 402? I am looking into a 402 all forged.

old motorhead

Time for some upgrades to the heads and intake mani. Stock 243 heads are a pretty serious bottle neck on a 403. Lots of options depending on goals and fatness of wallet. LS3 heads and intake mani is a pretty cost effective route. Lots of threads on the subject. Sucks that you have to do it.....but it's an "opportunity" to make it much better

06z06_427

My friend just went with the same 403 setup and some wcch ported ls3 heads. He is very happy with all the new torque and piece of mind that comes with a forged motor.

'VETTE PHASE

The 403/404 uses slightly oversized pistons and requires a .0010 overbore.

Vito.A

You will probably need to have the block bored/honed to fit the pistons.

I like your list of parts except the Eagle rods. See if they offer an upgrade option for the rods. Most Eagle parts are imported from China. Some of the parts are great, especially for the price, but the quality control over the steel alloy and the forging/machining process is not the best. It only takes one flaw in 1 of the 8 rods to have a big problem. The best example is, what other companies do you know that sells brand new parts that are already .010-.030" undersize?

Your LS2 cathedral port heads will be ok, but definitely a limiting factor. At the very least you need to have them rebuilt with new guides and new exhaust valves. You could have them ported, but with the cost of porting you could buy new L92 heads that are identical to the LS3 rectangular port head and offer a lot more potential. Scoggin Dickey had new L92 heads for $150 each as well as several upgrade packages. The best option is a new pair of bare L92 heads and send them to WCCH for new guides, porting, and new quality 1-piece valves. The only negative to this is you will need 8 new offset LS3 intake rockers (these are very inexpensive) and a rectangular port intake like an LS3 or a FAST 102. Your headers and everything else will swap right over to the new heads.

Hope this helps!

Corvettinator