Okay guys, this is my dilemma. I've got a Shafiroff 540 shortblock I'm putting together. It's got SRP forged slugs with those 10cc mini domes. I topped it with AFR 315 heads. I've got a Comp Cams solid roller cam.

Here's the problem. I was checking piston to valve clearance and...you guessed it, I've got NONE! graemlins/angry.gif The intake valve won't quite open all the way (it's hitting the piston). I assume that the problem is too much lift? And/or too much duration? But I'm not sure. Here are the cam specs:
11-773-8
I / E
@ .050* 254 / 260
Advert. 292 / 298
Lift .660 / .666
Lobe sep. 110*

Any suggestions as to what I should do? I am guessing I need a different cam. Any suggestions? Here's the combo:

Street 540ci: 10:1 compression
AFR ported 315cc heads--119cc chambers
Dart single plane intake
2 in primary headers into a dual 3 inch exhaust
TH400 tranny--haven't figured out stall for a converter yet
12 bolt Rear gears--probably 3.42

Any suggestions or ideas?
THANKS! graemlins/beers.gif

Ben,

I have the exact cam, I have 10cc SRP Pistons (probably the same exact pistons you have), 119 CC Canfield heads. My Merlin II block was decked .025 so pistons are .005 in the hole. I have 0.125" +/- Piston to Valve clearance. Cam is 2.5 degrees Advanced. Are you sure everything is in right?

Your combo does sound Familiar ;) I will do a search smile.gif

Somethings wrong...
My Merlin III block is also decked, the 10 cc SRP pistons are .007 in the hole and with a .041 head gasket. The Dart 325cc Pro I have been flat milled to 114cc chambers and have 2.30" intake valves. With Harold's cam, 287/295, 256/264 @ .050, .660 lift,110 LSA installed at 105, and 1.7 rockers, there was still TONS of valve clearance... .200+!

This is VERY disconcerting!! :mad:
I have a Merlin III block as well, Bill. Any ideas what the problem could be? This doesn't bode well at all! Now I'm worried!
Keep the help coming guys!
Thanks.

Ben

I also have Merlin III block, Shafiroff's short block....005 in the hole, Wiseco pistons, .808/.776 cam and have plenty of clearance with .041 Cometic gasket.

How are you measuring?

I should also say that I have Dart 355s flat milled to 114cc as well.

yanniz,

Measuring? I wish I could! I can't even rotate the motor all the way over! I tried the clay method but the valve runs into the piston and won't go any further! I can't believe this!! graemlins/angry.gif I am worried!!
Help!

Did the Short Block Come with the cam installed.

Either way Take it out and reinstall it, I bet you find the problem..Don't be worried just yet, it is probably installed 90 or 180 degrees off or something.

Tom,

No, the shortblock didn't come with the cam. I got it myself. Maybe I'll have to try reinstalling it. Hopefully that takes care of it! :rolleyes:
This isn't supposed to be that hard dang it! :mad:

Thanks guys! graemlins/thumbsup.gif

Ben,
hang in there, I think you will be fine, I agree with Tom, check your cam....I have been were you are so many times the last 2 months, it is not even funny...things will work out, usually it ends up being something simple..

Have you called the guys at shafiroff? I would talk to Mike there, he will help you.

Good luck and let us know how it turns out.

Ben,
The guys are right...gotta be cam phasing.
Please don't take this the wrong way BUT...just checking your expertise.
Have you done this before? Got anyone around to help degree that cam in?
You've obviously got a lot of time and money invested there and I sure would hate for something to happen!

Bill,

No offense taken. This is my second motor. I built a blown 383 a couple of years ago. Lost that motor in 4000 miles to a defective piston. So this time around i am making sure about everything. Cam phasing has got to be it if everyone else has so much clearance with a similar set up. I have a degree wheel (I have yet to use it however!) so I guess that will finally come in handy!

I was going to give Shafiroff a call tomorrow if I couldn't get a sound answer from here. But of course you guys pull through.

Thanks guys. I am feeling a little more relieved. I wasn't super confident about the set-up. I'm glad to hear that others are using a similar cam with a similar motor.
I appreciate it!!!

Ben,

You'll get it right..

When you start thinking about a Torque Converter I have some test results with 3 that I tried and their performance results. I am hoping my info could be useful especially if you go with the 3.42 gear.

Also, I run a Hughes TH400 with a Man/auto Valve body forward pattern. This will be the fourth season on it. $950 delivered from Summit (used 10% discount when they used to have them).

Tom,

That sounds great. I'm still trying to figure all that stuff out. I am pretty sure about the 3.42 gears. I haven't picked up a tranny yet either. Right now I have a tired TH350. I've looked at Hughes as a possibility. That's a good price you got! As far as converters go I am still up in the air so any recommendations would be great. I can't say it enough but I appreciate the help!
graemlins/thumbsup.gif

I think Comp Cams grinds those cams with a small--about 4°--advance built in, as Lunati does.
Use my 'Quick-n-Dirty' method for determining if the cam is in right.
Put the cam in 'Dot-to-Dot', then turn the crank over once. The dot on the cam gear should be at the 12-O'Clock position, and the dot on the crank gear should also be at 12 O'Clock.
Now check the lifter heights if the manifold is off, or check at the retainers if the manifold is still on. Using something like a Machinist's 6" steel rule, get the height of the intake lifter, or the height of the intake retainer. Measure from spring seat to top of retainer, or from lifter boss to top of lifter. WRITE this height down!
Do the same measurement on the exhaust lifter or exhaust retainer. Write this number down, too.
If the cam is in the right place, and advanced 4° to 6°, the difference should be about .025" to .040" at the lifter, or .035" to .060" at the retainer, the intake being closer to the head(retainer) or the intake lifter being higher out of the hole.
If the exhaust lifter/retainer is higher, the cam is retarded---pull the timing chain and do it over.
If the lift difference is over .100" in any case, you're over a tooth off, check it out....
This works with any normal cam-in-block engine.

UDHarold

BTW, what UltraDyne made for Scott Shafiroff was the BB318/325R12, 284/292 at .050, 199/205 at .050, .774/.774 valve lift, and 112 LSA.
This cam went into his 540s, and I don't remember any piston-to-valve problems. I'm sure the pistons were made or cut for the cam.
This cam is extremely easy on valve train parts.

UDHarold

Ben
Double check that when your timing chain is "dot to dot" that your #1 piston is at top dead center.The Keyway should be approx at 2:00 or 45° from 12:00 when #1 is at tdc.

Guys,

Thanks for all the help!

I am going to give the timing set a look and see if I did in fact put it in right tomorrow. I think I did. If it looks good I'll give Harold's suggestion a try. And either way I'll let everyone know. I was just sure there wouldn't be a problem with this cam and piston/valve clearance. Very perplexing!

UPDATE!!

For anyone who cares here is what I found. When I looked at the timing set I noticed a faint set of additional number stampings! So I had the wrong 0 lined up with the sprocket. I in fact had the cam advanced with an additional 4 degrees! graemlins/clonk.gif The crank key was at 12 and the sprocket mark was at 6. Now the key is more at 2 or 3 and the sprocket mark meets the other 0 on the crank sprocket. And the piston is at TDC in this position like it's supposed to!!! I am VERY relieved to have this apparently fixed. And a good lesson learned.

Thanks to all who replied!

graemlins/beers.gif

graemlins/hurray.gif graemlins/hurray.gif graemlins/hurray.gif graemlins/hurray.gif graemlins/hurray.gif graemlins/hurray.gif

graemlins/beers.gif YYYYEEEEEEEEHHHHHHHHAAAAAAAA !!!!!
It pays to double check your work.good luck

graemlins/thumbsup.gif
Glad it all worked out!

Good News Ben... graemlins/thumbsup.gif

good to hear Ben,
now as far as measuring your p/v clearances read this thread below..
;)
P/V clearance (http://drr.infopop.cc/eve/ubb.x?a=tpc&s=3476075&f=80760912&m=935609736)

yanniz,

Thanks for that link. I checked my clearance by bolting on my head without a gasket and used the clay method. I have .200+ clearance with the clay plus my head gasket thickness. I think I am in good shape now! I can't wait to drop this guy in! ;)

Thanks again guys!

Did you install the lower timing gear? DOes it have three keyways? Sounds to me like it's on the wrong keyway. Or did you already check that?

Tom

Tom,

I checked the key way and it was on the correct key. The upper gear was out of whack. I had the dot on that aligned with the wrong Zero. Not one of my better moments. graemlins/clonk.gif But I'm glad we got it figured out!