As some of you guys here already know I recently acquired a 77 corvette that the PO spend tons of time and money replacing all the suspension, brakes, wheels, tires, exhaust, interior and on and on. Anyway he had a place in north jersey build the engine for him in 08. Now, he installed it in the car in 2010 and according to him the cam went bad. So far it sounds like improper start up and cam break in procedure. When I discussed it further he said he did not run it at 2000 rpm for about a half hour to break in cam which is what you are suppose to do. Now in 2010 he replaced the cam and lifters with the same kind that the builder put in and even changed the springs and rockers just in case. The engine has not been run since the initial start up and I have all the reciepts for everything he has does to the engine and the car since he got it in 08.



I pulled the motor and disassembled it and everything checks out except this dummy installed the new cam without any moly lube on the lobes and lifters but I can tell it hasn't been run yet. I am sure the motor is what he described it to be.So that is the story.
Now my question is to those of you guys that are experienced at building hi perf chevy small blocks. What should I expect from this engine once I reinstall and break in.
Block bored .03 over
eagle rods, arp bolts
cloyes double roller timing chain and gears
melling hv oil pump
speed pro flat top coated pistons
moly rings
dart iron eagle heads-part#10024266
Head chamber volume=67cc
intake valve 2.02
exhaust valve 1.60
intake runner volume 165cc
Comp cams 12-210-2 part #
Gross valve lift @.006 in-268 ex-268
Duration @ 0.50 in-218 ex-218
lobe lift .03020 on both
lobe separation 110.0
comp cam lifters
Comp Cams guided roller tipped rocker arms 1.52 ratio
Comp cams springs part 3981-16 which according to cam card are required.
Edelbrock performer intake manifold
edelbrock carb 600 cfm electric choke.
I am told 9.70 is the comp ratio?
Thats it. What can I expect out of this thing. Im a Bodyman not an engine builder....


One last thing, Shouldn't these heads have guide plates on them?

 

The heads: Don't use guide plates See the red

Dart 10024266 - Dart Small Block Chevy Iron Eagle S/S Cylinder Head


The Dart Small Block Chevy Iron Eagle S/S Cylinder Heads are the perfect way to squeeze a little bit more performance out of your street engine. **Dart S/S heads are legal in many racing sanctions with iron head rules!

Features:
Premium high density cast iron for maximum power and durability
Extra thick decks for increased durability
Intake Runners: 165cc
Combustion Chamber Sizes: 67,72 & 76cc
Enlarged pushrod holes for high-ratio rocker arm clearance

I would be very scared that there could be some doo-doo in the motor from the wiped cam deal.

I would take that **** all apart clean and flush it to be sure it is clean.

The combo you have there is a good street set up and should be a nice street ride

 

Thanks Oldschool. I took the pan off and it was clean. I also removed the oil pump and disassembled it and it was good, But will replace anyway. Took intake off and the lifter valley is clear. Took of timing chain cover and chain is fine. Did not remove heads since I think that may not be necessary? Should I ? And should I also pop a couple caps off to check for bearing damage? I am thinking of just pulling the cam to coat with moly lube and the lifters too. And just button it all up till I am done with the engine bay which predictably has turned into another project.

 

With a cam failure you need to inspect all the bearings. You also need to flush all the oil passages. It only takes sliver to ruin everything.

As for power, sounds like about 300hp, with lots of low end torque. Nice street motor, almost smooth idle.

 

Thanks Zwede. I will take your advise. I will inspect all the mains and rod bearings. But do you think the heads should come off too? How would you recommend would be a good way to flush all the oil passages. Or am i looking at at a total disassembly and having the block and crank sent out to have it cleaned and check by a machine shop?

 

One point about the guide plates - enlarged pushrod holes have nothing to do with guide plates. Heads either use self aligning rocker arms or guide plates. I believe yours are in the guide plate category. (The enlarged pushrod holes provide clearance for the offset pushrod location when you use 1.6 :1 rocker arms rather than the stock type 1.5:1. The pushrod holes don't guide the pushrods.)

 

Old iron factory heads did not use guide plates, nor self aligning rockers. The pushrod holes were tight and acted to align the rockers. Since iron eagles are factory replacements, I think they are the same way. Maybe worth a call to Dart to confirm.

As for taking it apart and having it cleaned: Yes, a very good idea. If all the bearings check out with no damage or dirt you could get away without a full disassembly and clean. But if this is a motor you want to depend on and you're not in a big hurry, then taking it apart and having everything cleaned properly would be a big plus.

 

Well, I've been wrong before but, like you said, the OP needs to check this out for sure.

 

Some good info here:

http://www.hotrodders.com/forum/guid...em-101022.html

Whether or not guide plates are needed on iron eagles depends on runner size. Also note what they say about needing hardened pushrods with guide plates. Also note that if the head has slots for the pushrods you cannot add guide plates without opening the slots up (make them wider).

 

http://www.dartheads.com/products/cy...der-heads.html

Click on "Small block heads important information". In there it states no guide plates for the 165cc iron eagle, all other sizes require them.

 

According to the Dart website 10024266 heads with the casting number 20 which are the ones I have do not require the plates. So am I correct in assuming that the guided roller tipped rocker I have are correct. I am confused because the push rod holes are round not slotted and bigger than the push rods. Also what do you guys think about roller tipped rockers? These are comp cams 1.52s. Should I just install plates and get new rods and full rockers instead?

 

If your rockers are like these
http://www.summitracing.com/parts/cca-1417-16/overview/
Then guide plates should not be used.
I am using these on my SHP dart heads and do not have guide plates. Using guide plates with these rockers can in fact cause binding problems.

 

Maybe someone drilled out the holes. Could you post a picture?

There are 3 ways to align rockers:

Cast iron push rod slots
Self aligning rockers (align to the valve stem)
Guide plates

You must only use one of these. Never use (for instance) guide plates AND self aligning rockers.

 

wash and clean ''EVERTHING'' at least 2 times,then start looking for scratches,cleaner cant hurt

 

Reelav8r-
Yes those are the rocker I have.

Zwede-
I understand. There can only be one way of rocker alignment per application. In my case it seems that it is self aligning roller tipped. How good they are I have no idea since I have never owned a car with these in.
http://i959.photobucket.com/albums/a...g?t=1379874895

Dmaxx3500-
You and everybody else have already convinced me that a full teardown and a trip to the machine shop for a full cleaning of all the oil galleys in the block and crank.

Thanks to all of you who have so far replied to this thread. I feel somewhat confident now in the direction that I should proceed from this point on.

 

I'm using those Comp self aligning 1.52 roller tip rockers on my GM Vortec heads (no guide plates) and I run the hell out of it. They are working fine.

 

Same here. 1.6 ratio is only difference. I run it up to 6000 rpm no issues. 1000 miles so far. They also fit under stock valve covers without hitting.

 

My factory L-82 heads as well as LT-1 heads used guide plates from the General. Would they not be useful on other heads as well?

 

Thanks guys, Thats reassuring.
I just come in from my garage. I proceeded to remove all the rockers,pivot *****,push rods, timing chain and lifters. So far everything is brand new like the po said and my receipts prove. Also the cam. Again, brand new and not run yet. So I then proceeded to remove one of the main caps and one of the rod caps. Oh my! completely wiped out. The rod cap wasn't so bad although it was shot, But the main bearing had almost all the tin worn off exposing the copper surface underneath. Its a good thing this guy did not fire this thing up after replacing the cam and lifters. Also glad I decided to trust but visually confirm the work on the engine. This thing I would say would of taken a major league dump.When I pulled the cam out even I could tell that the new bearing in the front of the block was GONE! So that is that, Of to the machine shop for a complete once over. Not what I wanted but not totally unexpected.
You guys think that a cam upgrade to something just a little more,just a little more umph! be good to go with the set up the engine has already. Just as long as it still idles ok and not like a harley sounding like it wants to shut off. You guy so far have been great Thanks...Rich

 

The factory heads that used guide plates had wider slots as well as hardened push rods. You can run guide plates on iron heads that didn't come with them as long as you open up the push rod slots and switch to hardened push rods.