More 408 Stroker Build Problems

Author Topic: More 408 Stroker Build Problems  (Read 3513 times)

Offline matt63

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More 408 Stroker Build Problems
« on: October 30, 2005 - 06:40:57 PM »
I'm glad I started this project in September and not in January.  I got the crank installed to my satisfaction and proceeded to assemble the rods and the pistons - no problem after figuring out how to install the spirallock rings.  After installing #1 and #2 piston assemblies in their bores I thought I would rotate the crank.  Big problem.  The counter weights on #1 and #2 hit the bottom of the piston at the bottom of the stroke.  I'm guessing its the Eagle forged crank since there is not alot of extra meat on the pistons.  I'll have to talk to the engine machine shop who machined the block and balanced the rotating assembly tomorrow.  I'll don't see many options but to pull the crank and get the counterweights machined down and rebalance it  Hopefully they only need the crank for this.  If they remove all this weight will they have to add weight somewhere else on the crank i.e. mallory metal?  This could get expensive.  These engines full of aftermarket parts are definitely not "bolt together". Anybody run into this before?

 
Matt in Edmonton

'68 Valiant
'73 Cuda 340 4 speed (408) SOLD




Offline Chryco Psycho

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Re: More 408 Stroker Build Problems
« Reply #1 on: October 30, 2005 - 08:55:47 PM »
yup , everything has to be carefully checked with any custom / stroker build , possibly the pistons were not specifically designed to work with the Eagle crank ,possibly the pistons can be massaged to work , I asuume the crank is not hitting insiode the block at all? also check the windage tray & oil pump for clearance

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dodgetkboy78

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Re: More 408 Stroker Build Problems
« Reply #2 on: October 30, 2005 - 11:17:40 PM »
oops.

No biggie! I think Chryco is right, pistons can be clearanced a bit.......................

Hope it dont happen to me on my 4" 318.

Offline matt63

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Re: More 408 Stroker Build Problems
« Reply #3 on: October 31, 2005 - 07:19:37 PM »
The Eagle SIR rods are supposed to clear the block without notching.  So far so good.  The machine shop who did the block and balancing wants me to bring in the rods, pistons and crank so they can have a look.  I would prefer to machine the crank as all of the rings are installed but I'll go with whatever they recommend.  Also, is anyone familiar with the Cometic head gaskets?  I would like to run a 0.050 gasket if they can be bought.

Matt in Edmonton

'68 Valiant
'73 Cuda 340 4 speed (408) SOLD

Offline Chryco Psycho

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Re: More 408 Stroker Build Problems
« Reply #4 on: October 31, 2005 - 11:25:25 PM »
Cometic Gaskets are awesome , probably the best gasket available , I have used them in the past & it is basically the only gasket I will use with Iron block & alum heads they are available in .045, .051, .054 & various other thicknesses as well , order them now , they could take a while to get the exact thickness you want   

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Offline matt63

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Re: More 408 Stroker Build Problems
« Reply #5 on: November 01, 2005 - 09:35:13 PM »
Thanks Chryco.  Are they typically available from the speed shops or must they be ordered direct?
Matt in Edmonton

'68 Valiant
'73 Cuda 340 4 speed (408) SOLD

Offline Chryco Psycho

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Re: More 408 Stroker Build Problems
« Reply #6 on: November 02, 2005 - 12:14:33 AM »
depends on the speed shop , , probably just as easy to order directly

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Offline matt63

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Re: More 408 Stroker Build Problems - Update
« Reply #7 on: November 03, 2005 - 09:27:03 PM »
Dropped of the crank, pistons and rods at the machine shop.  They are going to grind the piston pin bosses and mill the crank counterweights as the interference is slight but NFG.  I also asked them to mic the rod journals and bearings. They say that excessively large clearances are common with some of the aftermarket stuff (greater than 0.003 inch).
Matt in Edmonton

'68 Valiant
'73 Cuda 340 4 speed (408) SOLD

Offline ACE_5150

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Re: More 408 Stroker Build Problems
« Reply #8 on: November 06, 2005 - 10:09:45 PM »
oops.

No biggie! I think Chryco is right, pistons can be clearanced a bit.......................

Hope it dont happen to me on my 4" 318.

Dude , not trying to be mean but I dont understand why in the hell you would waste money on stroking a 318. The whole point of stroking ( in this context :) , is to gain cubes, so why not use a 360 block and  go to a 412? I'm confused.
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Offline matt63

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Re: More 408 Stroker Build Problems
« Reply #9 on: November 07, 2005 - 07:19:50 PM »
Dude , not trying to be mean but I dont understand why in the hell you would waste money on stroking a 318. The whole point of stroking ( in this context :) , is to gain cubes, so why not use a 360 block and  go to a 412? I'm confused.

I would think that stroker 318 pistons would be custom units ($$$$)
Matt in Edmonton

'68 Valiant
'73 Cuda 340 4 speed (408) SOLD

Offline Plum6Pak

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Re: More 408 Stroker Build Problems
« Reply #10 on: November 07, 2005 - 07:31:37 PM »
Dude , not trying to be mean but I dont understand why in the hell you would waste money on stroking a 318. The whole point of stroking ( in this context :) , is to gain cubes, so why not use a 360 block and  go to a 412? I'm confused.

Hey Ace, not trying to be mean but what in the hell rhymes with 412? Haven't you ever heard the song: "She's real great my 408"? Sometimes you need to sacrifice a few cubes to make things work out.


Offline matt63

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Update on 408
« Reply #11 on: November 10, 2005 - 06:42:52 PM »
The engine shop milled the Probe pistons so they don't hit the Eagle crank and rebalanced.  Now they say that the Eagle rod big ends are all over the place (oval).  Nothing $600 shouldn't fix! Trying to stay cool here...

Matt in Edmonton

'68 Valiant
'73 Cuda 340 4 speed (408) SOLD

Offline cutting torch

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Re: More 408 Stroker Build Problems
« Reply #12 on: November 10, 2005 - 06:44:10 PM »
Dude , not trying to be mean but I dont understand why in the hell you would waste money on stroking a 318. The whole point of stroking ( in this context :) , is to gain cubes, so why not use a 360 block and  go to a 412? I'm confused.

You only lose 18 cubes to a 360 (both .030 over). If you already have a good 318 block to use, and no 360, why not? Plus, if you have an emissions test to pass, the smaller bore will treat you better. To each thier own. Hell, I've got some weird stuff on my car that makes people ask why.

torch

Offline cutting torch

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Re: Update on 408
« Reply #13 on: November 10, 2005 - 06:47:47 PM »
The engine shop milled the Probe pistons so they don't hit the Eagle crank and rebalanced.  Now they say that the Eagle rod big ends are all over the place (oval).  Nothing $600 shouldn't fix! Trying to stay cool here...



I hope they torqued the caps before they measured (I would assume they did). If they are out-of -round, I would contact Eagle to see if you have any recourse. They might make it right.

torch

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Re: More 408 Stroker Build Problems
« Reply #14 on: November 10, 2005 - 06:58:04 PM »
It is hard to realize the full performance potential when utilizing a 318.  It is not necessarily the cubic inches per se that hurts it. You can stroke it, cam it, exhaust it, induction it and put a set of killer heads on it.  The one problem that is way more difficult to address is that with bigger heads/valves and the smallish bore, the smaller bore tends to shroud the valves. This shrouding disrupts the flow of the mixture entering/exiting the cylinder. This creates a decrease in HP that is not created in a larger cylinder bore engine.  All things being equal, a 340 or 360 gives you "free" HP by not stealing it in the first place.  Just my 2 cents..........Oldschool