New Flathead in the works....build thread !!

Ah well its been coming for a while but yesterday I picked up the block, crank, rods etc from the machine shop at last.

My prevous mill had a piston pin lock let go and it trashed a bore so I decided to treat her to some nicer goodies and some beefing up of the spinning assy/bottom end.

We're still in Winter mode here so this will be my final Winter project till our Spring/Summer/Events season weather hits.

Specs are as follows:

3 5/16" + .030"
Scat 4 1/8" crank
Scat H Beam rods
Ross forged pistons
Custom steel caps
1" Hard Blok short fill
Studded heads and mains
Ported int and exh
1.6 Chevy valves
Custom Tatom blower cam, adjustables, Isky springs/shims, c/moly retainers
Edelbrock 1116 CNC, deep chambered heads
Hayden Mitchell blower intake
Modded pan with crank scraper and windage tray
Elec dist/MSD 6BTM
GMC 4-71, 2 x Stromberg WW / Holley 600 DP

Today thoroughly cleaned the block and its oil galleries. Then painted the block inside and out and she turned out nice. The next step in to add my bearings and double check all my clearances, clean the crank thoroughly before the crank goes in for the final time.

Wish me luck hehe

Rat

 

Way to go Rat . . . maybe I'll just change your name to 'Flat Rat' for the coming months Keep us posted and if there is anything you need, drop me a line -- will be happy to help an OZ friend. Looking forward to seeing this engine bark a bit.

 

Yours too Steve....? Never seen that b4 so thought it was kinda rare.

The circlip's eyelet that broke loose was travelling thru the hollow pin and ended up trashing BOTH side of the bore.

The weird thing was, the CR in that cylinder was spot on when I tested her. Go figure...

B&S....yah was trying to get a hold of you but no dice - you're a busy man mate....

Will be in touch, I'll give you the scoop and btw, Ive got that five-letter-word itch.........BAD.

Rat
Rat

 

Cool!
Can`t wait to see more progress!

What are the specs on the cam?

Michael

 

great thread
I'll be watching closely on this one.
I've got a 49, destin for my 30 coupe, that will need attention soon.

-Chris

 

Looks like a "KILLER" from here! Keep us posted!

 

Now...to relieve or not to relieve - that is the qun....

Rat

 

Looks like a great start to a great mill!

I'll be watching this one...

 

lookin good keep on truckin...........

 

Anyone ran a 4 1/8" arm with Scat 2.139" rods in an 8BA block? Was there any clearance issues with the rod bolt nuts and the pain rails?

From what Ive seen we should be good to go...can anyone confirm?

Rat

 

You should have no problems with the pan rails, but depending on which
S.C.A.T./Eagle/CAT rods you have you could have issues with the bottom of the bores. If these rods are the early ones that are close to 644 grams then you will have to notch the bottom of the bores (like notching the bores when stroking a 351w to 408ci), if they are the newer 550 gram rods you should have no problem as they narrowed the web of the beam...........and they will fit fine.
Ask me how I know the older/heavier/stronger rods won't clear the bottom of the bores....

IMHO

 

will follow...just wondering - what pistons were being run with the C clip malfuction?

 

I remember reading that the later ones should clear OK - I have the newer, 550gm rods, thanx for the heads up.

Stillrunners, the pistons were heavy duty cast 4 ring slugs. They came out looking real nice too,even in a blown application. The piston with the broken circlip was in great nick as well, its was just the eyelet off the circlip that broke off and did the damage.

Rat

 

Rat, there's some great knowledge regarding relieving over at Fordbarn. Some of those guys like JWL and Ol Ron have been building killer flatties for decades.
Sounds like its gonna be more fun than a goanna down yer pants.

 

Looking Good......

Chopped 2010 is 1.5 months away.... you need some Local miles under your belt before you make the trip to Newstead. Let me know if I can help.

 

I was just wondering if you would mind giving me that motor when you finish it? I sure do like me some flathead. That is if you don't have any plans for it which I'm sure you don't.

 

Can't wait Frank. I picked up my first flatty about 2 weeks ago (99A ). I'll be keeping an eye on this.

 

I have a Scat 4 1/8 x 3 5x16 kit that has the late 550g rods and has
buick bearings(2").
It fits very easy in the block without any work.

 

What, no Hemi?
Glad you've stuck with the flatmotor though Frank. Looks like a killer motor on the way.

 

Since you have the high flow heads, i would only unshroud the valve area, like a ramp.

Like B&S documented here on the HAMB on the street engine

 

Cool Frank, will follow along to see how it all goes. Mines nearing needing a freshen up.

 

My thoughts too actually!

Your only going to be creating lower comp by relieving right?

So if you were running the motor before with the right comp AND now you have the High Flow Heads also, wouldn't think it'd make a hell of a difference, if any IMHO!

In actual fact, your comp would go too low right?

Just my 1 cent!

What do you think Micky?

HC.

 

Mickey Im gonna have to dig em out !!

Rat

 

Cool send it over DR....gimme a chance to knock this one over though !!LMAO

Rat

 

Hey Mick,

Thought of that option too...but any kinda relief might prevent me from running another type of cyl head down the track....

Rat

 

Haahhahahahahaha good one Frank, but you know me I'm a glutton for punishment. I'll be doing it myself Got an EK needing a driveline freshen first. Leaking like a sieve!

 

Sounds like its time for a transplant....lets see, the worlds FIRST FLATHEAD POWERED EK HOLDEN !!

Has a sweet ring to it no?

Told you I need help......

Rat

 

Looks great.

What valve seat pressure will you have with the isky springs? The reason I ask is that in some blown applications, you may need to raise the seat pressure of the valve to stop pressure flutter. (When forced induction opens and closes the valve)

This can occur if the engine is running overdrive with the blower. I have also seen it when under driven too. I once had the pleasure (not) of diagnosing bent valves in a BB chev. A guy bought and bolted up an 8-71 to the engine, ran 4% overdrive on valves that had 90lb seat pressure. With the cam that he had put in and only having 0.050 piston to valve clearance, he bent some valves. Some of the valve clash with the pistons was due to valve float (bounce) but on other valves you could see seat burn marks (induction flame) on the inlet valves and valve seats. I know that a flatty can't have piston to valve clash but its worth checking the seat pressure for a blown application. You should just do it anyway...blown or not. Part of good rebuild practice.

P.S. The cam card should give you a recommended seat pressure. If not, give the cam manufacture a call.
AFL

 

Aaah yep! You got it bad...

 

Just some food for thought...........................in a blower motor you really want to concentrate on the head and what you do with the block in the way of relief doesn't effect the CR that much but can make a difference of flow in and around the valves. In the motor I started to build, the Norm Frick heads were 78cc, but if I were to change heads and go with a carb'd motor I would change the size and shape of the combustion chamber to get the CR up but the block relief would still be there as I believe it takes stress/head away from the area that is prone to crack and helps flow around the valves and over the piston.
We will see what happens on the dyno.

IMHO