Totally confused, WTF!?!

[Greg@GLD]

Ok, I decided to tear the 347 apart because I am in process of making a big change. I have one head off the motor. I can now clearly read the piston part number. Now things get interesting. 10.25:1? 10.60:1?
NOPE!!! How about 8.75:1????

WTF!?! I can clearly see part number 10668-030 stamped on the top of the piston. By the matrix on this page: http://www.probeindustries.com/Pistons/Pistons_SRS/Ford/302/Ford_347_dish.htm
with a 64CC head (which my GT40X are) it says 8.75:1 :thud:

My build sheet says "Probe 10.25:1 oil control" but there is no part number specified.

Ron Robart says "we NEVER build motors like that, you have 10.60:1 compression"

Now I don't know WTF is going on!


ARGGGHHHHHH!!!!!

[QTRMILE]

and your are 100% sure those are Probe pistons?

It might be time to CC the dish, CC the chamber, measure your deck height and figure this out yourself so you know FOR SURE wtf you're dealing with. This is madness, lol.

[Greg@GLD]

Rob, piston says PROBE right on the top (the probe logo actually!) and the part number is clear as day. It's a dish piston, there is no question. The heads I bought brand-new from FRP and they are indeed 64CC GT40X that may have been milled slightly to clean them up. Even if they were the 58CC- max compression with the 10668-030 is 9.30:1.

[Greg@GLD]

taking a pix, back in a bit...

[Greg@GLD]

Ahh, can't get a clear enough pix to display here, but it's a Probe #10668-030 period.

[QTRMILE]

I don't understand, lol...

[Greg@GLD]

I don't either Rob!!! Nothing makes sense now. I have to call Fox Lake on Tuesday and find out WTF is up here.

What a freekin' nightmare.

[BBATCO1]

If its a dish it isn't 10 to 1 for sure. A flat top in a 347 would give you approx 10 to 1 to 10.5- 1 in that motor a dish should be much lower.....This is just an approximation not to be confused with the truth....

[QTRMILE]

If its a dish it isn't 10 to 1 for sure. A flat top in a 347 would give you approx 10 to 1 to 10.5- 1 in that motor a dish should be much lower.....This is just an approximation not to be confused with the truth....
Which is exactly what I've been thinking, but his builder SWEARS otherwise, and he was having issues with just 5# of boost. I know you can't depend on the compression test results, but those numbers combined with those dish piston + those heads should be perfect for that blower. Especially with the moderate amount of boost you were running. I don't think too much CR was the issue you were having, Greg. I think you (and I and most) assumed that was the issue because we were all going on the premise you had uber CR. I bet it was somewhere else (obviously if you have 9:1 or less...)

Despite the confusion, I think this is good news :thumbs_up

[BBATCO1]

Camshaft dynamics can cause high cylinder pressures in the upper rpms also. There are many variables other than static compression. There are 9 to 1 motors that use race gas N/A beacuse of reasons like that. If I was Greg i would get ahold of Mark O'neal on www.hardcore50.com He is mister Probe, and will be able to help him out......

[MAT88GT]

to hell with it...follow Rob's advice and measure before calling...you've wasted enough time on the phone already

figure the static compression and go from there, chasing your tail (phone cord in this case) isn't getting you anywhere with the boooooost

[Greg@GLD]

I have to admit I am a little leery now. I know for a fact that I have 64CC heads by part #, I know I have the dish piston by part number. Something else you guys may find interesting- the fire ring between #6 & #7 is distorted. I think what is happening here is I don't have enough fuel for when that blower is cranking up. SQ trims make more boost than a base S trim, plus I have that powerpipe. I was probably ragged edge before with the last setup. 30's and an FMU is bad news, I think that's where the problem is. Will most likely go to a PMS and 42's.

Oh what fun this is.

Can you imagine- If I had gone ahead and ordered a low-comp 308, and then discovered this? Or bought that $400 set of pistons, only to find out I already had them?!?! :mad:

[Greg@GLD]

Are they dish pistons then? Like BBatco(real name?) says, if theyre dished, theyre nowhere near 10:1. I'd find myslef a different engine builder while you're at it........


They are for SURE dished! They look EXACTLY like the pistons here:

http://www.probeindustries.com/Pistons/images/12352.jpg

[Greg@GLD]

There's no doubt here Danno, I have 4 pistons I could look at, the part number is easy to read, they are not flat-tops, they are dish-tops. I know the part number of my GT40X's are 64CC.

This ain't no flat-top!

http://www.mach1media.org/images/347piston.jpg

[BBATCO1]

Definate lack of fuel. 30# are good enough for a 347 N/a but not with boost. My buddy has a stock bottom end 302 and runs 42#ers to get the tune right. I bet those 30s went static at part throttle. Put some new cometic head gaskets on there while you have it apart. I would have to say fuel is your problem now since you rulled out the piston therory......

[BBATCO1]

That 302 I speak of has gone 128mph with many fox lake products on it.....

[Greg@GLD]

Cometics- three weeks minimum wait. :(

I want to check if my T-rex is powering up! I'll get this thing solved. I need a break now, gonna cruise the Mach down to the Highway and hang out tonight.

Thanks for the replies everyone...

Greg

[Jesse James]

Extreemly interesting Greg. Sorry you're having to go through this Bro. But something just didn't sound right during the trial runs. I didn't have a 347, but man, to get enough fuel for 8-10 psi of boost on a 302 with stock pistons and bump stick we had to overdrive the crap out of the 24lb FMS blues and mess with the diaphrams quite a bit. Definately sounds like a fuel issue. I was running nearly 100psi, but that's how much fuel it took with my GT40 upper and lower, 65mmTB, 77mmPro-M to keep from bucking and or detonating. A chip from an ex Ford guru "Mike Wesley" finally helped out some, and less boost. Dished Pistons, holy cow!! Blower pistons. I think someone was on the right track about the bumpstick Greg. No expert here at all. Just sharin some experience.
Good Luck!! :cool: :shifter:

[QTRMILE]

3 weeks? Ack, I might need to make a phone call for ya... .030?

[Tom]

I seem to recall Victor Reinz offering multi-layer steel gaskets. I'll look into it when I get back to work Monday. Yes, I'm working Monday.

[Tom]

Found the numbers. 4.030 opening, .040 operating thickness Victor #54290

[Nick 1]

Cometics- three weeks minimum wait. :(

I want to check if my T-rex is powering up! I'll get this thing solved. I need a break now, gonna cruise the Mach down to the Highway and hang out tonight.

Thanks for the replies everyone...

Greg

Did you call Randy ????? I bet he has them in stock !!!!!!!!!!!!!!!!!!!!! :thumbs_up



Nick 1

[flyin_hawaiin]

DSS has the cometics in stock too..

[Jim]

darrell might have some too greg.

[1slo5.0]

I have a bunch coming, but still waiting on them. I called Cometic last monday to find out where the hell my order is and they said they would ship out at the end of the week.

[Greg@GLD]

I do like the head gasket to be a "fuse". Rather blow a fuse than a motor!
The cam is not an issue, it's a great blower cam and everyone I have talked to about it says to keep running it.
My problems are all fuel related. Feel kind of stupid actually. The last setup I ran was only a 302, had a much smaller cam and less boost. So the 30's with the FMU might have worked ok and been right at the boiling point. I should know better, kind of embarrassed. 347, powerpipe, bigger cam- need much more fuel because much more air is going into the motor obviously.

42's and PMS. Ditch the FMU, run stock pulley, go to a 255 LPH pump, should be set to run a boosted 347.

[Greg@GLD]

Maybe the Tweecer RT would be a good choice? Much less $$$ than the PMS, and people seem to like them?



Worth a look anyway..... (http://www.tweecer.com/products.htm)


no way PMS much better product. I am well aware of those Dan, thanks anyway...

[NitrousEdge]

DSS has the cometics in stock too..


Welcome to the site Bob! :rockon:

[Greg@GLD]

He's been lurkin', we finally got a post out of him. :D

[Greg@GLD]

What makes it better? A friend of mine was looking for a piggyback setup like these, but doesnt know much about them.

This is going to become a hijack. Do a search. I think I know at least 5 people with the PMS. The support for is much better, easier to program/use. No external PC or laptop needed to program it. Has NOS and boost functions, and AFM will send you a program based on your combo parameters.

[Greg@GLD]

Here Dano, read over these instructions for some info....

http://www.andersonfordmotorsport.com/pms/ControllerUsersGuideEECIV7-2004.pdf

[Saltmaker]

If you haven't bought one yet check this out!
http://cgi.ebay.com/ebaymotors/ws/eBayISAPI.dll?ViewItem&rd=1&item=7919487319&category=33596&sspagename=WDVW
looks like a great deal and its the new one!

[Greg@GLD]

Yes I did, and the two other ones, only problem is it's for the 93 and earlier. :(
We need to hook up on that T-rex man!

[Saltmaker]

YES we do!!