Engine exploration...., Is this engine any good? Options

[bostonmeche]

I appreciate all the input.

I am just trying to keep this engine from gooing oil all over the ground and since the engine is out, perhaps pick up some extra lost hp.

What is the cheapest way to put the engine back together and still get some hp back. Could I just hone the cylinders and put in new piston rings? I will definitely buy the Tom Wilson book. Perhaps that will answer a lot of my why and what if questions. The Haynes manual is good for seperating things and putting them back together but does not really explain the trade offs of making certain decisions.

This engine is only supposed to stick around until I have the funds, time, and experience to do a -6 cyl. I don't want to spend a bunch of money on this engine only to sell it to someone for 1/4 of the price. The flip side is that I don't want to grenade the engine because I think there are people out there that would probably be willing to buy some or all of it. Every $1 saved is a $1 spent on the 6 (IMG:style_emoticons/default/mueba.gif)

[McMark]

Hone and rering should get you back into "decent" territory and should give you a few more years. Of course, that assumes everything else is setup okay. If it was running before you should be able to rering and hone and bring the compression back up. You could have the heads checked out by a machine shop and have the valves reground and possibly the guides replaced. That should keep the heads happy.

[bostonmeche]

I realize that this question is really loaded but....

How much does a head job with a valve regrind cost? As I start asking around I want to know when I'm getting screwed.

Also, if I re-ring the pistons, do I still have to split the case? I thought I could just pull the cylinders and slip the pistons in from the back. An aquaintance told me that it won't work like that but couldn't explain to me why.

[Bleyseng]

You don't have to split the case to install pistons and cylinders, they detach and reattach just to the rods.

Head work depends on the work that hasta be done.

Geoff

[ArtechnikA]

How much does a head job with a valve regrind cost? As I start asking around I want to know when I'm getting screwed.

Also, if I re-ring the pistons, do I still have to split the case?

if you have inspected the heads and found no cracks, call RIMCO and ask for a quote on a basic valve job. tell them your valve sizes but presume they'll be okay with just a freshening and will not require replacement. i'd replace the springs on principle but if they meet spec you might be able to slide on that.

you don't need to split the case, but you WILL need a 'take-apart' ring compressor. there are a few styles, i donno what's the flavor of the day for 96mm.

if you are removing the pistons, it's my recommendation that you remove and recondition the rods, and replace the rod bearings. rod bearings have a hard life in our engines and this, too, can be done without splitting the case. lots of people don't do this, so it's clearly optional, but it's pretty normal in 911-land for people to cheap out on top-end work, doing a valve job and re-ring, only to lose a rod big-end bearing a few thousand miles later. your call.

[applescotty]

you don't need to split the case, but you WILL need a 'take-apart' ring compressor.  there are a few styles, i donno what's the flavor of the day for 96mm.

I've had luck using a non take-apart ring compressor. If you compress the rings and slide the piston in just up to the top of the wrist pin hole while it's off the engine, you can remove the ring compressor and then attach the piston to the rod and finish sliding the cylinder down into place.

applescotty

[bostonmeche]

OK, I'll be putting an order into Pelican tonight that includes among other things Tom Wilsons book. In the mean time, I was hoping someone could tell me how to properly measure the piston rings and valves so that I can:

1. Order the piston rings

2. Tell someone like Rimco what I have for valves so I can get a quote.

I would like to get the car put back together soon so I can continue to enjoy it for the precious few good days we have in New England.

[ArtechnikA]

..hoping someone could tell me how to properly measure the piston rings and valves so that I can:

1. Order the piston rings

2. Tell someone like Rimco what I have for valves so I can get a quote.

valves - measure the diameter of the head in mm. it doesn't have to be accurate to many decimal places, you just want them to be aware that you have non-stock stuff.

piston rings - i'd probably call the guys at EBS for those... the piston diameter you have. very carefully remove the rings from one piston - try not to break them because at some point it will be nice to compare end gaps ... v-e-r-y accurately measure the top compression ring, the 2nd compression ring, and the oil control ring thickness. PROBABLY they will be some even fractional number of mm. IMO - the guys at EBS are much more likely to be able to identify and source individual ring sets than Pelican. as much business as i do with Pelican, for engine hardparts, i go to EBS...

you will probably have some choices on ring type to make - Total Seal or not, for instance. my suggestion: describe your intended use to the guys at EBS and let them make a recommendation.

i've heard both praise and horror stories on Total Seal rings, so i suspect that means there are lots of variables at play.

[rhcb914]

Hey Bostonmeche,

I'm also located in Medford! I have a set of micrometers that I can lend you to measure the rings if you want. Email me rhcb914@yahoo.com if you are interested.

Tom Wilsons book is great! I have used it to build a few engines including the one in my 914, a 1911cc. Not an expert by any means but willing to help you out. (IMG:style_emoticons/default/biggrin.gif)

-Rob

[davep]

The guy you need to talk to is Jake Raby. He posts a lot here and on the shoptalk type4rum. He reccommends Hastings rings, nothing else. However, since you have non-stock P&C set, you need to find out the manufacturer of the P&C set. Only then can you be sure to get the correct type rings for the pistons. They can vary in thickness, number and location of each type. When installing the rings, there are very specific ways to align the gaps. Get the Raby video on assembling a type 4 engine. You are going to need a lot of help on this project, so don't be afraid to ask lots of questions.

[bostonmeche]

Rhcb914,
Thanks for the offer. I'll probably will take you up on the advice and help. I don't need any mics though. I have a nice digital verier and a qualified micrometer to get me by, hazards of imagineering work (IMG:style_emoticons/default/laugh.gif)

Where you located? I'm two houses down from the big Kappy's (for those not in the know Kappy's is this gigantic liquor store, an anathema to the blue law toting puritans that had founded the state). You should come over sometime and view the carnage and have a beer or two. I'm a homebrewer and have a healthy stout that would kick your (IMG:style_emoticons/default/bootyshake.gif)

ArtechnikA,
Again, thanks for all the advice! It is really appreciated. (IMG:style_emoticons/default/beer.gif)

[silver2.0]

Don't forget to buy a ring expander. You are lible to break the new ones, or scratch your pistons pulling the old ones out. Also, clean the
carbon up off the bottom of the ring groove. Also, Look really close for cracks in your heads, the 2.0 heads crack super easy. Good luck, and keep asking questions, that's what we are here for.

[lmcchesney]

Bostonmeche,
You probably do not realize that you have one of the very good engine building groups just west of you. Contact Mike Seymour at Autocraft engines in Marlboro, Mass. Do not be afraid of the pricey quotes on their race engines. I'm sure they will be glad to advise you. However, remember, it is the peak of racing season and those demands will come first.
http://www.autocraftengines.com/
L. McC

[rhcb914]

I'm on the other end of the Fellsway. Up by wrights pond.

Love to swing by for a (IMG:style_emoticons/default/beerchug.gif)

Email me and we will get together.

[bostonmeche]

Brad,
(Not that you didn't know) you were right on about the valves 48mm exhaust and 38mm intake.

Where are the likely places to find cracks in the heads? I'm looking near the spark plugs and near the valves and haven't found any yet. Not that I want any, I just want to make sure I'm looking in the right places especially since I remember someone saying 90% of cylinder heads have cracks.

Also, there seams to be a maching break out between the two valve seats in cylinder 4 (the right side of the first picture) I wouldn't think that this matters because it occurs outside the seating area. What do you guys think? Sorry about the crappy picture, I've been scrubbing the heads but it takes a bit longer than I thought to get all the carbon off.

[davep]

Don't be too concerned about cracks near the valve seats. Here in Canada we rarely see them. Only in the deep south or California do they seem to crack readily. Glass bead or walnut shell blasting is good to clean the carbon from the heads.

[silver2.0]

I agree with the bead blasting comment, but my 2.0 heads were cracked majorly when I aquired the car. Cracked heads are usually a sign of a bigger problem, or a poor repair. It won't hurt looking.

[Jake Raby]

Ambient air temps have very little to do with the temps that the heads ee. The heads in my cars run the same winter or summer, regardless.

What kills heads is improper tuning which makes heat, and drivers that use 5th gear when they should be in 4th.. slow fan speeds and more load on the engine builds heat in the heads like a maniac.

90% of the 2.0 heads that we see have cracks around the plug holes. Those are welded up, and 12mm plugs are installed to add strength to the chamber to prevent re-cracks from occuring.

Those 48x38 valves are far from an optimum 80% I/E ratio, guaranteed.... The intake port on the TIV already flows well out of the box, making it larger increases the demand for the exhaust to flow more to get the 80%.....

Huge intake valves, require cams with even more split duration on the exhaust to gain a combo that is efficient...

The largest intake valve we run is 44mm, and thats on a 2739cc engine... Its good for 239BHP, as a daily driver at 10:1!

[bostonmeche]

Jake, are you trying to tell me my engine ain't as good as yours? (IMG:style_emoticons/default/mad.gif) (IMG:style_emoticons/default/laugh.gif)

I ran a few numbers once you told me the 80% ratio rule... Who ever built my engine followed it to the "T" 38/48 = .79 Now I realize that this is probably not right ratio that you are refering too. I would have to guess that you are talking about the skirt circumference. In the industrial valve world, we usually try to correlate flow from the circumference of the valve * the height that the plug (i.e. the head valve) is away from the seat. The only issue is that that essentially is the same because the valve strokes are equal (are they?) and Pi cancels out. So now I'm really confused. Are you talking about valve area when you talk about the 80%?

BTW, I didn't know you could make large hp reliable daily drivers out of 4 bangers. I was seriously considering your 2270 engine except that it only puts out about 160hp. I was hoping for a reliable 200hp at the least and ideally something good for 250hp so I am looking to do the 3.2. By the way, I consider reliable to be 100k miles without a rebuild or anything major to fix. Since this car is just a 2-3xs a week driver I figure it would take me 10 yrs or more to get to 100k.