8ba piston and ring replacement .

[37coop]

hi guys, I,m looking to replace the rings and pistons on my 51 f1 truck ,a couple of questions before I order them in the u.s to be shipped to the u.k , I havnt found the engineer who will rebore the engine yet ,the bores have a lip at the top so obvious wear . the question is ...do I buy the pistons and rings first and the engineer cuts to the piston size ,if so how do I know how oversize to go , or do I give him the block to measure and he tells me what to order? also I have the carpenter catalogue ,pistons from him o.k or would you recommend somebody else , sorry if the questions sound obvious to you but I havnt done this work before , many thanks , cheers jim.

[Joe Immler]

I would wait until the machine shop work is done "just in case." Let him tell you what sizes you need. A place you might want to contact for American made is :Egge Machine Co. 11707 Slauson Ave. Santa Fe Springs, Ca. 90670-221 562 945 3419 I am sure they have a web site also that you might check out.

[Mart]

Do you know what size the bores are now? It might at least give you a clue as to what sort of sizes you might be looking for. Are you looking for a big overbore or just the first convenient overbore size?

It might be worth talking to Miles at Jackhammer or Kerry Tate or Geordie Paul. They might be able to get stuff cheaper than you can do as an individual.

Mart.

[37coop]

Originally Posted by Mart

Do you know what size the bores are now? It might at least give you a clue as to what sort of sizes you might be looking for. Are you looking for a big overbore or just the first convenient overbore size?

It might be worth talking to Miles at Jackhammer or Kerry Tate or Geordie Paul. They might be able to get stuff cheaper than you can do as an individual.

Mart.

thanks mart, I,v never done this sort of stuff before ,I don't know the bore size ,I havnt got the required measuring tools, regarding the size of overbore I dunno ...there is a lip at the top of the bores but I wouldn't know what is severe or not......the names you suggested ,are they shops or engineering places in the u.k? I,ll google them and see what comes up ,thanks for your help , regards jim.

[ford3]

before you do any thing take the block to the machine shop and have it cleaned and then magna fluxed to check for cracks, if all is all ok have the machinest mic the bores and see how much it needs to be bored to clean up, then check for availabily of pistons that size, you may have to go a little bigger to find good pistons, egge makes decent pistons, but there quality control some times is poor, i order 8 pistons for my studebaker v/8, when they arrived the pistons lans werent cut in the pistons, for you that would be expensive and time consuming to send them back

[37coop]

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Originally Posted by Joe Immler

I would wait until the machine shop work is done "just in case." Let him tell you what sizes you need. A place you might want to contact for American made is :Egge Machine Co. 11707 Slauson Ave. Santa Fe Springs, Ca. 90670-221 562 945 3419 I am sure they have a web site also that you might check out.

thanks joe ,I reckon that is the way to go , I,v heard of egge and when the time is ready I think I will use them ,my friend with buicks has used them in the past , cheers jim.

[37coop]

Originally Posted by ford3

before you do any thing take the block to the machine shop and have it cleaned and then magna fluxed to check for cracks, if all is all ok have the machinest mic the bores and see how much it needs to be bored to clean up, then check for availabily of pistons that size, you may have to go a little bigger to find good pistons, egge makes decent pistons, but there quality control some times is poor, i order 8 pistons for my studebaker v/8, when they arrived the pistons lans werent cut in the pistons, for you that would be expensive and time consuming to send them back

I will do as you suggested and take the block to a machinist , I havnt got the pistons out yet and I think I will struggle to get the rings over the lip at the top of the bore ,I havnt got a "lip cutter" for want of a better word ,I want to do all I can myself to keep costs down , this truck is costing me big time , looked great on ebay but I still love it , cheers jim.

[rotorwrench]

Your chosen machinist will have to make the call on the next overbore depending on how much wear and the next up oversize to clean it all up. Most machinists will bore to the next oversize just shy of the mark then hone the cylinders to get the piston clearance just right.

[ford3]

37coop,the tool you need is called a ridge reamer, check with some of the parts stores, over here they will loan you one for free, with out reaming the ridge it can really be a bit*h to get the pistons passed the ridge

[Mart]

Kerry Tate. originalshrs"at"btinternet.com or 0776six70six087.

Geordie Paul trades as Duksville. http://www.duksville.co.uk/

Miles trades as Jackhammer http://www.jackhammerspeedshop.com/

Jim at Royal Customs builds a lot of flatheads for people. http://www.royalkustoms.co.uk/

Mart.

[krackerjack1951]

jim..i have a new set for a merc block and crank for 030 bore with the rings...however if you have a ford engine and ford crank you need ford pistons..if you dont see the top of the pistons stamped with the oversize # on them some one will have to probably measure the bore first and determine how much to bore to clean up the walls...before you get too far at least measure the stroke of your crank,,measure with a ruler if you have to,,3 3/4 stroke ford and 4" for merc crank..dont assume nothing..LMK how you progress..thx gary

[Ross F-1]

I assume over there you have only unleaded gas? If so, check your block for hardened valve seats. They are needed with unleaded. Ford got rid of them in mid-'50 and added rotators to the valves. They don't do any good with unleaded.

[Bassman/NZ]

Pistons can be expanded if the bore wear is within reason, and if the pistons are in good nick. This used to be a popular method back in the 50s and 60s, I dont know if it is still done. The machinist would have to make the call on that.

[ford3]

Bassman, your right , its called knurling,was done a lot back then, but unless the pstons are rare and real hard to get new ones are usually less than the labor to knurl them

[JWL]

Be careful with the ridge reamer! Many years ago a friend brought his block to me for re-boring and the oversize required an extra .040 because of his inept use of a ridge reamer.

You are probably seeing the worst of the wear at the top of each cylinder. Inspect the bores to be sure there are no grooves or scratches and have someone use an inside micrometer to find the cylinder with the most wear(largest diameter). Base your piston oversize purchase off of that information. In other words if the wear is at 3.230 buy pistons of +.060. If there are grooves you will need to measure or estimate those depths to determine best oversize to procure.

[Frank Miller]

I had a block with stock pistons. It would not clean up at .020. There was still a bit of an eyebrow at the top. The Egge 4 ring pistons have worked just fine in a stock 49 8BA.

[El Rat]

Bore and/or hone the block after the pistons are purchased. Measuring is much easier after the ridge is cut out. If you use an inside mic or snap guage it won't matter...

[Karl Wolf]

Originally Posted by Ross F-1

I assume over there you have only unleaded gas? If so, check your block for hardened valve seats. They are needed with unleaded. Ford got rid of them in mid-'50 and added rotators to the valves. They don't do any good with unleaded.

If you have insert seats in the block, and I think that a 1951 block should- they will be very good seats- don't let anyone replace them.

Karl

[Ol' Ron]

Badger makes an OEM style piston, with similar weight as the original. They are 4 ring thermal controlled for a very tight fit and come in most standard over sizes. When your machinist measures your present bore I'd go at least .020" larger

[37coop]

Originally Posted by Mart

Kerry Tate. originalshrs"at"btinternet.com or 0776six70six087.

Geordie Paul trades as Duksville. http://www.duksville.co.uk/

Miles trades as Jackhammer http://www.jackhammerspeedshop.com/

Jim at Royal Customs builds a lot of flatheads for people. http://www.royalkustoms.co.uk/

Mart.

cheers mart ...the only v8 people I know over here are belcher and nordian ,I,ll have a phone round and see whats what,cheers jim.

[37coop]

wow lots of info and thanks for that , I will crack on getting the pistons out the weekend ,I will try to locate a ridge reamer ,I have taken on board all advice and hopefully the task will be more straight forward than I first thought , cheers ,jim.

[GOSFAST]

Originally Posted by El Rat

Bore and/or hone the block after the pistons are purchased. Measuring is much easier after the ridge is cut out. If you use an inside mic or snap guage it won't matter...

I believe it would be much safer to have the shop bore (only) all 8 holes, once they are cleaned up you'll know exactly the o'size to order the pistons.

I'm assuming they'll leave a minimum of .006" to finish-hone (with a block-plate of course).

There's absolutely no reason for a ridge-reamer, been building these units for over 40 years now and have never owned one!! Knock the pistons out, if the ridge is that bad the worse will happen will be some "broken" rings!

(Add) We are still building a small number of these yearly, but enough to keep a good inventory of parts in stock.

(Add-2) Just a "tip" but I would have all 16 guides bronze-lined during this rebuild, you'll never experience a "hung" valve.

Thanks, Gary in N.Y.

P.S. This is by far the safest method to machine the block without shipping pistons back & forth. You can bore any block without the pistons, but should have them at-hand before finish-honing.

[JWL]

NO, do not bore the block without knowing about the availability of pistons in the required size. Unless you don't care about cost of custom pistons. If the machinist cannot determine the size requirement BEFORE boring find another shop.

[GOSFAST]

Originally Posted by JWL

NO, do not bore the block without knowing about the availability of pistons in the required size. Unless you don't care about cost of custom pistons. If the machinist cannot determine the size requirement BEFORE boring find another shop.

Hi John, let me just expand some on my post.

With the best bore gauges available (Sunnen's, I have 3 here) you won't always find the worst worn spots in the bores, they will only get you in the "ballpark".

Based on the "predicted" size (e.g. .020, .030, .040, .060 etc) from their readings you take the time to bore all 8 holes to make certain the gauge didn't "miss" one bad section. All your doing here is guaranteeing you have ALL 8 holes straight & true.

From this point you will know the exact o/s pistons required. It's fairly straightforward.

Here's an example, just because the mike/guage shows .023" wear (difference), it's not necessarily always "centered", it could be worn .009" on one side and .014" on the other (very common actually). If this is the case then a +.030" piston WILL NOT work even with the guage showing .023"! It would take a +.040" to correct the unit. Assuming you pre-ordered the +.030"
pistons based on the above scenario (.023" wear), you would proceed to bore the block (.024" over) for the +.030" size and THEN find it's a no-go". I hope this is clear, but it's how we do it here. Not usually on the more conventional builds (SBC, BBC, etc), but mostly on these Flatheads.

(Add) I would also like to mention that the price "spread" on cast replacement pistons and "custom" Ross pieces (rings included) is closing in, and in some cases not all that bad when you consider you have forged pieces and usually a "moly" ring pack. This ring setup alone will be a fairly substantial power advantage.

Thanks, Gary in N.Y.

P.S. We've bored numerous castings (all mfrs) and have found occasional "worn" spots missed by the bore guage fingers. Sometimes it's from a particle of sand falling out or a broken ring wearing some extra material from the bores. This is difficult to measure with even the best equipment. I'm not even talking underneath the "normal" ring wear pattern from directional change, but down deeper in the bores.

[Ronnie]

Originally Posted by JWL

NO, do not bore the block without knowing about the availability of pistons in the required size. Unless you don't care about cost of custom pistons. If the machinist cannot determine the size requirement BEFORE boring find another shop.

+++2 on that statement.
There is more than one way to determine the size the bore will clean up at.
A good shop will have the size determined fairly quickly.A good shop will tell you what is required and get the parts in.

R

[billwill]

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Originally Posted by 37coop

hi guys, I,m looking to replace the rings and pistons on my 51 f1 truck ,a couple of questions before I order them in the u.s to be shipped to the u.k , I havnt found the engineer who will rebore the engine yet ,the bores have a lip at the top so obvious wear . the question is ...do I buy the pistons and rings first and the engineer cuts to the piston size ,if so how do I know how oversize to go , or do I give him the block to measure and he tells me what to order? also I have the carpenter catalogue ,pistons from him o.k or would you recommend somebody else , sorry if the questions sound obvious to you but I havnt done this work before , many thanks , cheers jim.

Let shop tell what size to order or they will order them for you

[37coop]

Originally Posted by billwill

Let shop tell what size to order or they will order them for you

blimey my head is spinning , cheers bill I think I will settle for that .