To update, LH has a good engine but shipping was going to be prohibitive. So, I've opted to continue w/the plan to take my bits to the machine shop. That'll provide something to do w/Dad, as RW pointed out. And, it'll get me an extremely good engine for less than a grand.

As explained in the what-have-you-done thread, I'm prepping the block by pulling all the plugs so the vat can clean the passages out. And, I'll run a tap through all the holes so everything is ready to go. The plan is to take it up on Tuesday, and it'll be ready when we get back from visiting our kids later in the month.

So, if any of you have suggestions on how to get it ready and/or how to put it back together please let them fly.

 

I would also chase the threads with a tap AFTER it's been boiled & cleaned (basically, during assembly).

 

Good point since "stuff" will probably get in there during the machining process. In fact, it kinda begs the question of why do it before machining. But, I think the answer is that the cleaner it is before going into the tank the more gunk the tank can get out.

Another question to all. Someplace I read or saw where some 4 bbl implementations used a side-to-side sheet metal shield below the intake manifold to keep the oil from burning on the exhaust passages in the intake manifold - similar to what Mopar used. Do any of you know about that? (Yes, ctubutis, I can look it up, but......) The HO didn't have one like that, but does have the riveted-on shield on the bottom of the manifold.

And, the HO intake manifold has a vacuum operated diverter valve for exhaust gas - w/o vacuum it is closed and doesn't allow exhaust to flow into or out of the intake manifold on the driver's side. Further, there is a vacuum operated heat riser valve that goes between the exhaust manifold and the exhaust pipe on the driver's side. So, do I really need either or both? The '82 2bbl didn't have either and it was driveable in cold weather.

But, the HO also has an EGR unit that sits between the intake manifold and the carb. Just slips on the studs like the carb does. I've heard many of you suggest keeping EGR on the engine, but is that true of the slip-on unit? And, in the case of the HO's intake manifold, the exhaust gas comes from the heat riser passage.

Or, do all of those 3 valves go together to make up both an EGR system and a heat-the-carb system?

 

All v8's use some sort of shield under intake manifold. They all ran exhaust through the intake from head to head to create a hot spot under the carb to keep the fuel atomized. The shield keeps the oil splashing under the intake from burning into a big glob, and then falling off into the engine clogging everything up.

The cleveland style engines(your 351m) used a full shield that also served as a intake manifold gasket. That's just they way they did it, and they could get away with a metal gasket because there is no water flowing through the intake to leak. Most others used the riveted style shield.

The heat riser was made to clog one side of the exhaust to force a lot of flow under the carb for quick warm-up. After that, the small flow that normally goes under the carb was all that went through. I was also wondering why they added the extra little flapper door in the intake passage, the one on my intake is broken. I was just going to take it completely out and plug the hole to allow normal flow under the carb all the time. I am not sure of the exact reason why they added the extra control door on this intake.

If you are going to run the original Ford?Holley carb, I would keep the EGR. If you are going to run a aftermarket universal type carb, I would get rid of it and use a blank spacer plate. If you use the EGR, you need all the controls that go along with it.

 

Yeah, the turkey pan.... it's one variation of an intake manifold gasket, my 2V M-block used the same from the factory.



I installed a 4V manifold and didn't use that gasket (though I STRONGLY considered it, purchased & returned it unopened at least twice) I instead got some sort of Mr. Gasket (I think) kit that had two exhaust-manifold-looking pieces, threw out the end pieces and just used black RTV.



Pix are from Rock Auto, I looked up a 1984 F150 with a 351W 4V engine.

If you were in Minnesota I'd say "yes, it's a good idea" but I really kinda doubt it's needed where you're at.

I've heard rumors that my M-block had similar stuff from the factory but a PO had apparently removed it (if it in fact existed on my engine).

AFAIK they're all the slip-on units that get sandwiched between the carb & manifold.

If you are rebuilding this engine and doing a straight-up timing chain (and replacement cam?) I'd probably forego the EGR valve stuff BUT you may experience pinging problems under load & heavy acceleration if you do that, you may want to have your distributor re-curved while you're doing all of this engine building stuff to avoid that.

 

Hmmm. Now I have a dilemma. I have the Holley and it appears to be in good shape. But, I also got a 600 CFM Edelbrock/AFB in the deal. It is the #1406 that is jetted a bit leaner so was planning to run it - for a while. That's because I plan to ultimately put it on my father's '81 351M when I get the truck.

And, I do not want all pollution controls that came on the '85 - vacuum hoses going everywhere. I assumed that I could build up the needed vacuum delays & switches to make the EGR operate. But, what do you mean by "all the controls"?

 

Ctubutis - Ahhh, it is the M that has the "turkey pan". Boy, am I biting my fingers since they want to type something derogatory.

No, in Okiehoma it doesn't get too terribly cold and I have AWD vehicles for when it does. Guess I'll ditch the heat riser. And maybe even block off the passage?

And, I will put the Comp Cams XE250H in this engine along with the straight-up timing chain. So, may also pass on the EGR.

As for consulting the CD, I need to set my shop's Windows machine up so I can access the CD from my easy chair via this Mac. Just forget to do it until evenings.

 

Whatever you do, do not block the passageways completely at the head openings. The hotrodders go on and on about keeping heat away from the intake and the carb, but I speak from experience, if you want a really cold natured finicky engine that refuses to run correctly when it's cold, go ahead and block the passages completely. Been there, done that.

Since my extra little flapper door control is broken on my intake, I was going to pull the mechanism completely out, and block any holes left so exhaust could flow freely under the carb, but not leak out in the engine compartment. But I never used the manifold, so I never did it.

And by EGR controls, yes I mean all the vacuum lines and vacuum control valves that control the EGR. That's what all that mess is on top of the engine. You can't let the EGR work at idle, or when the engine is cold, and some of the EGR systems needed a flow control system controlled by venturi signals. It's a real mess.

 

Well, I bet the turkey pan would not have fit anyway. I had a 351c that was a 2bbl engine, and wanted a 4bbl intake for it. Ford didn't make one in this configuration, just like they didn't make a 4bbl intake for the 400 you have. The aftermarket is our only choice and guess what? The turkey pan would not fit under the aluminum aftermarket intake. I bet it would not fit under your aftermarket 400 intake either.

 

Got it - let exhaust heat through. The voice of experience speaks loudly to me. Thanks.

So, how's this plan sound: Leave off the EGR valve and use, from the bottom up, a gasket, a block the thickness of the EGR valve, another gasket, and then the carb?

That begs the question of what block to use. I could make or buy one out of aluminum, but Al conducts heat quite well. On the other hand, would a phenolic block withstand the heat from the exhaust? It would be protected by the gasket, but the mounting area for the carb is cut away to allow exhaust to get to the EGR valve.

Would a picture help? And, I could include the flapper door in the pic if that would help you.

 

Sorry, Dave. I confused you with my poor description of the situation. What I have now is a Windsor, which is what I'm building up. The 335 series engine is a 351M in Dad's truck - which I hope to get when he's done w/it. (In fact, at 91 he's done w/it but the realization/acceptance hasn't set in yet. We told him he can't drive until his eye sight gets better and apparently he's hoping or expecting that to happen as he hasn't said we should get rid of the vehicles.)

Since I've driven his and mine back-to-back and know the huge diff in the acceleration, even tho the only major diff is that his is 4x4 and mine's 4x1, means I'm going to have to find some steroids to inject into the M. So, I've been chatting w/Chris behind the scenes because he's been there, done that.

 

If the exhaust passage is opened to the bottom of where the spacer would sit, use alum.
Plastic will eventually burn thru, so will the gasket. Ask me how I know......
Speaking of spacer, edelbrock says the use only a 4-hole spacer under thier performer series carb, not an open one. I dunno why.....

The heat risers in the heads/intake can be blocked completely for one type of application. LP or CNG only. Both use a heated vaporizer, so the heated intake is redundant, and can even lower power.
On a gas engine, the heat is a good thing. I blocked the coolant passages in the intake on my RX7. When the temps are below 40, it has major driveability issues until the engine warms. Not a problem, as I rarely drive in those temps anyways.....

 

Here's a 1000 words:


The lozenge-shaped hole at the top is where the exhaust comes from the manifold to the EGR unit. It is 1 3/8 x 1/2". And you think exhaust will eventually eat through the gasket and then would devour the phenolic block? What would keep the exhaust from doing the same thing if I used aluminum as the block?

Also, at the bottom is the vacuum-operated flapper that keeps exhaust from actually flowing across the manifold unless it is opened by vacuum. Of course, exhaust will still get in from the other side and it can leak by the flapper, although it is a close fit.

So, the consensus is:

• Block off the flapper valve hole and don't use the valve
• Ditch the heat riser valve that goes between the exhaust manifold and the exhaust pipe
• Ditch the EGR valve
• Use an aluminum block between two gaskets with the manifold being below and the carb above the sandwich

All agree?

 

For an aluminum block between gaskets (as you're describing it) what I did is cut a piece of aluminum beverage cat a bit larger than the hole, I think I then glued it in place (kinda-sorta) using Permatex Hi-Tack, I think that was to keep it from shifting around as I mucked with the other components.

Opened it up around a year later (I forget the reason) and looked at it, everything was still in really good condition with just a slight bit of black carbon build-up.

Some people were afraid the high temperatures of the exhaust would burn through it pretty quickly but that doesn't seem to be the case.

'course, I'd put only about 1,000 miles on the engine before looking at it, so YMMV.

 

Ok, I can go one better than the beverage can. The HO comes with an aluminum heat shield about 1/16" thick that goes between the EGR valve and the carb. It kicks up in back to clear the EGR valve itself and extends forward of the carb as well. E4TE 9S596AA

How 'bout from the bottom up it is manifold/gasket/heat shield/gasket/phenolic spacer/gasket/carb? That way I keep the carb cool and use the existing stud - although those would be easy to change out. And, it may take a special gasket between the manifold and heat shield due to the exhaust gas.

I personally don't like the heat shield extending out beyond the carb due to the looks, but can try it initially and if I don't like the looks cut it down.

Oh yes, I'll bet Edelbrock says use a 4-hole spacer to keep the low-end torque up. Been reading dyno tests of some manifolds and open spacers tend to help power in the higher range and vice versa.