440roadrunner

I'm not familiar with B1 heads, and have no idea what rockers you are using, but it's time to get a good mechanic and "get back to basics"

First question is, just how high DID you rev it?

Second question is, is your tach accurate?

Some general ramblings

Regardless of what cam/lifter/pushrods/ valves/ springs/pistons you are running, it is time to get REALLY suspicious of EVERYTHING, until you PROVE that it is OK

I'd get down to brass tacks with the builder, and find out what part numbers he used for pistons, what the measured deck height was, what valves, what pushrods, rockers, EVERYTHING. (Is this a mechanical or hydraulic cam?)

I'd find a mechanic who can do the following, and you don't even need to take the heads off to start the process

Pull the valve covers and with a wrench, slowly revolve the engine over, watching at least one set of valves, and check CAREFULLY for any binding or spring bottoming. You can use feeler gauges to help, here If the engine has some sort of aftermarket stem seals installed, but in any case, look for contact--or close to contact, of the top retainer with the seal/ guide. Do this on at least a couple of cylinders

Find out what the installed height of the valves is supposed to be and measure the stem height. This is done from the machined spring seat to whatever the spec says--probably the top of the valve

Pick an easy cylinder to reach, do a compression test, and make sure it's ok for compression. Now devise a hose--such as a compression guage hose with the foot valve removed--to pressureize the cylinder, and remove both springs from both valves. Make sure the air pressure holds them in place. At this time, you can also use a strong light and magnifier to inspect the top of the seal/ guide for contact, as well as the insides of the coils of the springs for contact.

I forgot to mention--you needed to go to the hardware store first, and buy a couple of lightweight springs that are similar in lenght to your valve springs. These need to be just light springs, something that you can push with your finger.

Install these light springs in place of the "real" ones. Now remove the air. Reinstall the rockers and pushrods, and set the valve clearance. DO NOT START THE ENGINE USING THESE SPRINGS Now rotate the engine through it's rotation--using a socket on the front balancer bolt--, and carefully, with your finger "helping" the valves, find the CLOSEST point, where the valves come in contact with the piston. You'll have to rock the engine back and forth a little with a wrench on the balencer. Do this for both valves

When you find the tight spot, mearsure the stem height with something accurate (best done with a dial indicator), and compare that to your "closed valve" height. The difference between the two will be the clearance you have between the valves and pistons. If you can't handle this, you should consider finding a performance oriented mechanic who can help you. This stuff is extremely emportant.


Unless you actually did overrev the engine by quite a bit, there is no excuse for a what, "professional"? builder to saddle you with this sort of situation. Six grand isn't much, anymore, for a performance engine. It makes me wonder about the guys you hired.

blue 68 gts

$6000 isn't much for an engine rebuild?

I'm not sure where you've been, but last time I checked, $6000 is quite a bit considering I only spent $2000 on my 340 rebuild by a very decent place.

440roadrunner

Well, that's your opinion, but it is the fact. Six grand, when you are talking aftermarket heads, big performance cams and pistons, is nothing, when someone else puts it together.

Here's some more stuff. I just did a little bit of Google

Google for the Crane manufacturers and other speed people for tech info, Isky, Crane, whoever. Here's some pages from Crane:

Here's a paper about their light duty "checking" springs which I mentioned above, and tells you a little about using them

http://www.cranecams.com/pdf/20e.pdf

which came from here

http://www.cranecams.com/?show=insta...ort+Compact%29

which came from their "technical help" page

http://www.cranecams.com/?show=technicalHelp


Here's the tech page from Isky. Click the link "Install a racing camshaft"

http://www.iskycams.com/techinfo_index.html


http://www.iskycams.com/camshaft.html

A very good article called "Cam degreeing"

http://www.iskycams.com/degreeing.html

440roadrunner

"who knew?" There's even a YouTube video on the subject


http://www.youtube.com/watch?v=TZ6kS...eature=related