When Stroker Motors Go Bad.... - Page 6

onefastmustang · #1 (**permalink**) 10-17-2007, 11:22 AM

Thats interesting.. I have a Motors mechanics manual here that says only the 69 has that height. I usually take what I find on the web with a grain of salt since it can be wrong so much.m I do agree that maybe getting a new block might be in order though since you never know with that one now.

BDR561 · #2 (**permalink**) 10-17-2007, 11:48 AM

Ahhhhhhhhhhhhh.............

fsstnotch · #3 (**permalink**) 10-17-2007, 11:54 AM

BDR.. don't get upset yet.... I have been finding SOME conflicting info. I'm going to find a definite answer.

fsstnotch · #4 (**permalink**) 10-17-2007, 12:04 PM

Nope, it is in fact true that the 71-73 D2AE-BA is 9.480 the 69-70's are also 9.480 but they are code C9OE-8.

If it were me, I'd look for an F4TE block and start over. Knock everything you have in that block out and put it up for sale on corral forums or here. Sounds like a good candidate for a 357. Only 400 miles on the .030 bore. as long as no damage was done.

Jerry Clayton · #5 (**permalink**) 10-17-2007, 12:33 PM

561

You really need to do a few things

1---measure the popup/deck ht of your pistons at tdc

2---check the timing of the camshaft

3---If the cam timing isn;t where it is supposed to be. correct it and then check Valve/piston clearance correctly and USE one of your compressed gaskets

4---if the cam is out of time and correcting it gets you a minium of .080 exhaust and at least .020 on the intake---
4a---buy one new piston and rings that matches your set
4b---buy one new cylinder head
4c---eight new exhaust valves. one new intake
4d---reassemble your engine and go to the event

5---if you can't get v/p clearance, get a new cam of lessor lift/duration and do 4a-d

Jerry

BDR561 · #6 (**permalink**) 10-17-2007, 12:41 PM

HJ,

Would you trust my existing pistons that have been rapped on? I will be check clearances this afternoon/evening

Jerry Clayton · #7 (**permalink**) 10-17-2007, 12:47 PM

If they are forged pistons and the ring lands aren't hammered so that the rings are tight in the groove, I'd put a piston in it and a head and go to the line for the next round---Did you do that search from my PM?

Jerry

Jac Mac · #8 (**permalink**) 10-17-2007, 12:50 PM

The ONLY block measurement you can rely on is the one You take with a large micrometer or vernier caliper. The rest is Hocus Pocus. Ordering pistons,rods,cranks without knowing the actual block height is a recipe for disaster,& you already have one of those.

Jac Mac

turnpike boy · #9 (**permalink**) 10-17-2007, 05:23 PM

Quote:

Originally Posted by Jac Mac

The ONLY block measurement you can rely on is the one You take with a large micrometer or vernier caliper. The rest is Hocus Pocus. Ordering pistons,rods,cranks without knowing the actual block height is a recipe for disaster,& you already have one of those.

Jac Mac

This is gospel. Since the motor is likely out of the car now anyway, drop it into the pickup or into the trunk and get your butt to a decent local machine shop - and PAY them to do the measurements.

Excaliber · #10 (**permalink**) 10-17-2007, 12:51 PM

I took my block to a machine shop and had the deck hieght measured from the crank centerline. I tried measuring it myself but couldn't get consistent results. I then had the block decked and with all the corrected measurements in hand orderd my custom (no return) pistons.

You just can't measure this stuff to many times!

BDR561 · #11 (**permalink**) 10-17-2007, 04:54 PM

Here's the info we have been waiting for....

Ex valve to piston clearance is: .039!!!!

The deck height must be 9.5 on my block as the current pistons with a 1.280 C/D are .005 in the bore... (9.5 - 1.280 - 6.2 - 2.0 - .015 = .005)

blykins · #12 (**permalink**) 10-17-2007, 04:57 PM

Well at least you know that the Probes will work now....and you don't have to run some silly head gasket and an overly large cam.

And you have some recourse against the builder.

Jac Mac · #13 (**permalink**) 10-17-2007, 06:44 PM

Quote:

Originally Posted by blykins

Well at least you know that the Probes will work now....and you don't have to run some silly head gasket and an overly large cam.

And you have some recourse against the builder.

Not until the ACTUAL Cam Timing is checked and the possibility of damage to the crank key is eliminated. If the cam timing is correct,then and only then do you have a case with the seller/builder.

Jac Mac

Jerry Clayton · #14 (**permalink**) 10-17-2007, 07:16 PM

And what is the intake clearance? You haven't verified the cam timing as yet-if it is even a little retarded you will have clearance issue at a few degrees before tdc.

I don't believe you have any recourse with the builder as it seems you bought an engine at a greatly reduced fire sale and you got what you got----

Jerry

BDR561 · #15 (**permalink**) 10-17-2007, 07:23 PM

Intake was .054

BDR561 · #16 (**permalink**) 10-17-2007, 07:28 PM

Jerry,

You're right.. However, I wouldn't have purchased it with a know short coming/defect/mistake in the build...

Watching the video again has verified most items and he made the mistake of not taking his measurments in the critical areas. I will verify the crank key and the actual cam timing, but expect them to be in order.

Looks like I will do the CC 35-772-8

Jerry Clayton · #17 (**permalink**) 10-17-2007, 08:10 PM

you might look at the 35-769-8 or the 35-770-8 as they will be more drivable on the street---I'd also widen out the lobe centers to 112 or 114degrees

Most of these cars are more fun with more reasonable setups in the engine department---you need to be able to cruise in high gear at 2000 -2500 rpm without bucking and jumping

Good luck

Jerry

496fe · #18 (**permalink**) 10-17-2007, 10:00 PM

If his clearances are .039 and .058 respecively then the problem is NOT timing. The problem is wrong pistons - somebody didn't do the right calculations. Probably the wrist pin position was wrong.

B.

fsstnotch · #19 (**permalink**) 10-18-2007, 02:59 AM

I would STILL have the deck height on that block measured! Especially when every single book I have says that the 71-73 D2AE-BA blocks are 9.480. Every reference I found on the net confirms this. Not saying they couldn't be wrong, but it's better safe than sorry. the only references I found that claimed 71-74 blocks were 9.503 are forums just like this. VERY unreliable source!

DEfinitely get that deck height measured properly before you start ordering parts!

Jerry Clayton · #20 (**permalink**) 10-18-2007, 07:12 AM

At this point---the pistons are in the hole by .005---it doesn't matter anymore what the block measures--what matters is the v/p clearance---he has a solid roller cam spec'd for a drag racing engine. He needs to put a properly timed cam in the engine for a more civilized application, something around the upper 500 low 600 lift at a duration that will run from make max power from 1500-6000 rpm !!!! The car is 2400-2500 lbs, runs outta aero at 140 and 450-500hp is drivable---anything more and its Russian Roulette to drive on the streets with cell phone talking/Starbucks drinkers/etc

Jerry