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Quote:
Originally Posted by LarsM View Post
Hi there, just stumbled over this thread here. I'm doing exactly the same job as you and I'm at the same stage as you aswell. I have a Instagram profile where I post some of pictures (LarsMK). Maybe I should start my own thread here...

That said, I've just shipped of my engine to one of the three Posche Classic Centres in the world for them the evaluate the engine longblock parts. I'll probably ask them to finish of the longblock as I will get some good papers on the job. The rest of the job I do entirely by myself. They charge 25 hours to build the longblock since I've already have it in parts. I'd probably spent 2 months doing the same job over the weekends I've got.

I'd love to share some experience. The biggest challenge I've had this far is a rounded off head stud barrel nut.... that was a real PITA!

Looking forward to follow your progress.
Please start your own thread around working with the Porsche Classic Center, that will be very interesting! For the OP - don’t be afraid to clean the case yourself with toothbrushes, green scrubbing pads, razor blades, simple green, brakeKleen, water and elbow grease, followed by a high pressure air blast (leaf blower is good). It will take a while but the results will be good.
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Old 12-01-2017, 10:10 AM
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As of today.. everything except my fan and fan housing, and intake runners have been delivered to Ollie's Engineering. (I need to have the intake runners cleaned and ported and polished and the fan media blasted to give it that new look)

The have the following:
1.) case
2.) crank
3.) rockers
4.) pistons @ cylinders
5.) cam towers
6.) pulley
7.) flywheel
8.) pressure plate
9.) upper and lower valve covers
10.) chain housing and covers
11.) head assemblies

I'm going to have them clean and inspect everything, fix any damage, port & polish everything that can be, and then figure out what performance upgrades to go with.

I expect to get everything back by May, as I'm estimating 10 weeks out.

While they are working on the engine, I'll plan on taking the front end of the car apart and getting as much hardware (oil lines, front fenders, etc...) off the car to have it towed to the local body shop to have some rust spots repaired.
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Old 02-26-2018, 12:32 PM
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ok.. so an update from Ollie's today...

crank looks good everything is STD/STD (that's a relief)
Case needs line boring, as they are starting to get oval shaped
along with barrel shims (?)
everything else is just going to be cleaned up and resurfaced & polished.

I'm also going to have the crank knife edged, as it seems this give the best benefit in 'bang for your buck'.


That 's the good news... the bad news???

The piston/cylinders are Alusil and aren't salvageable... was planning on going with 3.4 anyways, but hadn't planned on doing it this year.
Anyone have any recommendations? Can I buy a used set and still get the same benefit?
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Old 05-08-2018, 01:39 PM
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You could have your cylinders bored and plated with nicasil, then get matching pistons. $$ Search for Dracos build, I think that was the way he went.

Or a new set of pistons and cylinders. $$$$

Worth looking for a good used set, I guess. I had a bad cylinder on my 3,0 and found a good used replacement. So it's possible. $

Will the case use standard bearings? Are oversized bearings available?
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Old 05-08-2018, 02:30 PM
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I was thinking the same thing about the pistons and cylinders. If you're going to 3.4, there's no reason why you can't have those cylinders bored and re-plated with nikasil. Some have said the alusil cylinders are actually better candidates for the overbore and re-plate because the KS cylinder is a bit more structurally stable than the Mahle 98mm Nickies

but if you were just planning on reusing the pistons and cylinders as-is, then I can see how they may be deemed not serviceable. Since you were planning 3.4 anyway, now appears to be the time to do it since your hand is force. I agree with Gordon that the way to go is JE or CP Carrillo pistons. By the way you get a better "base" piston design from CP Carrillo with their standard X-forging- this is extra on the JE and called FSR (Forged Side Relief).

So you can get the cylinders bored & re-plated accordingly for the pistons and you're all set. Typical clearance is 0.0015" for JEs, 0.0020" for Carrillos. Note that if you have EBS Racing do the cylinders, they send them to Millenium Technologies. It's been found that their honing roughess was a bit too rough for various ring brands and they weren't sealing well, causing oil usage. So you would want to make sure they spec the fine honing. I have a friend here on the forums, who prefers to remain nameless, that had a similar problem as VFR750 experienced

Millenium Cylinder Fine Grit Honing Is the Right Way to Go

I'd be very careful with the knife edge approach. Not saying Ollie's doesn't know what they're doing. Just saying that you don't get much gains by doing it since they're only going to remove a rather small amount. And it's rather expensive.

My one personal experience is I had Marine Crankshaft do the knifing on a 70.4mm SC crank for me and it was a small amount at the ends.

Rod Weight Difference ... Other 993 engine build advice.

I don't think i'd do it again because it was a large cost of the overall crank work and the benefit is simply lighter weight (engine revs easier) vs. the downside being much more technical. The knifing simply lightens the crank, since there's no real windage losses here in a dry sump engine. So our cranks aren't spinning in a large bath of oil like a wet sump engine. The technical downside is there's a questionable benefit in messing with those counterweights since the the size is there for a reason- to counteract the weight of the piston and rod. So any knifing done should be minimal to avoid upsetting that balance between the counterweights and the piston + rod combo. Then I guess that begs the question, if the pistons and the rods are changed (let's say you chose to use CP 98mm pistons and lightweight Pauter rods) then should the crank counterweights be modified to reflect that change in piston and rod mass?

Here's a page from Neil Harvey's website to give you his take on it.

Living on the “Knife” Edge – performancedevelopments.com
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Old 05-09-2018, 09:08 AM
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Quote:
Originally Posted by KTL View Post
I was thinking the same thing about the pistons and cylinders. If you're going to 3.4, there's no reason why you can't have those cylinders bored and re-plated with nikasil. Some have said the alusil cylinders are actually better candidates for the overbore and re-plate because the KS cylinder is a bit more structurally stable than the Mahle 98mm Nickies

but if you were just planning on reusing the pistons and cylinders as-is, then I can see how they may be deemed not serviceable. Since you were planning 3.4 anyway, now appears to be the time to do it since your hand is force. I agree with Gordon that the way to go is JE or CP Carrillo pistons. By the way you get a better "base" piston design from CP Carrillo with their standard X-forging- this is extra on the JE and called FSR (Forged Side Relief).

So you can get the cylinders bored & re-plated accordingly for the pistons and you're all set. Typical clearance is 0.0015" for JEs, 0.0020" for Carrillos. Note that if you have EBS Racing do the cylinders, they send them to Millenium Technologies. It's been found that their honing roughess was a bit too rough for various ring brands and they weren't sealing well, causing oil usage. So you would want to make sure they spec the fine honing. I have a friend here on the forums, who prefers to remain nameless, that had a similar problem as VFR750 experienced

Millenium Cylinder Fine Grit Honing Is the Right Way to Go

I'd be very careful with the knife edge approach. Not saying Ollie's doesn't know what they're doing. Just saying that you don't get much gains by doing it since they're only going to remove a rather small amount. And it's rather expensive.

My one personal experience is I had Marine Crankshaft do the knifing on a 70.4mm SC crank for me and it was a small amount at the ends.

Rod Weight Difference ... Other 993 engine build advice.

I don't think i'd do it again because it was a large cost of the overall crank work and the benefit is simply lighter weight (engine revs easier) vs. the downside being much more technical. The knifing simply lightens the crank, since there's no real windage losses here in a dry sump engine. So our cranks aren't spinning in a large bath of oil like a wet sump engine. The technical downside is there's a questionable benefit in messing with those counterweights since the the size is there for a reason- to counteract the weight of the piston and rod. So any knifing done should be minimal to avoid upsetting that balance between the counterweights and the piston + rod combo. Then I guess that begs the question, if the pistons and the rods are changed (let's say you chose to use CP 98mm pistons and lightweight Pauter rods) then should the crank counterweights be modified to reflect that change in piston and rod mass?

Here's a page from Neil Harvey's website to give you his take on it.

Living on the “Knife” Edge – performancedevelopments.com

All good stuff...
I'm keeping my stock rods, but using ARP bolts.
I'm looking at getting MAHLE motorsports piston & cylinder set. I believe the brands you mentioned are more expensive.
I'm also going to have them install a set of AASCO titanium valve springs rated at 360lbs. (I've flip flopped on this decision a few times, but in the end, I plan on revving higher rpms than normal)
And finally, going to get the 964 cams for certain.
Unfortunately, due to life... I'll have to hold off as long as I can in ordering the piston/cylinders and cams.

I'm curious about your comments on crank counterweights and knife edging.
First off, out of all the optional performance mods they have available (boat tailing, moon cut, and knife edge)... they HIGHLY recommended knife edging the crank.

As for the counterweights... I'm not sure why that would be a concern as long as everything is balanced. A new set of piston SHOULD be all equal weight, which wouldn't have any counterweight effect on the crank... again, as long as everything was balanced, which it should be.
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Old 05-09-2018, 03:49 PM
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Quote:
Originally Posted by KTL View Post

Here's a page from Neil Harvey's website to give you his take on it.

Living on the “Knife” Edge – performancedevelopments.com
This was an interesting read...
I was curious about his comment "Taking mass away from the counter weights has a huge effect on the amount of twist the crankshaft would be placed under."

Is this a huge positive effect? or a huge negative effect?

also, he shows some pics of a damaged crank... but what I don't understand is what this has to do with knife edging? Clearly the crank in the pic was not knife edged... and I have NEVER heard of or seen a crank damaged from being knife edged.

I'm personally on the fence on whether or not to get the crankshaft knife edged. I've heard everything from that it will allow for faster revs, simply due to the lower mass, to improving oil flow through the engine.
I haven't heard any negative theories that show why this is a bad idea... other than if it was done by a semi-professional who didn't know what they were doing.
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Old 05-09-2018, 04:08 PM
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Actually if you have your cyls bored and get new JE or CP Carrillo for them, you're looking at approximately $2500-$3000. My costs are based on:

CP 98mm pistons are around $1100 retail
JEs are $1700.
US Chrome pricing for boring, plating and honing cylinders is $230 each retail.

A new set of 98mm Mahle Motorsport 9.8:1 pistons and cylinders from Patrick MS is $4680 on their site. So you gotta decide if the new Mahle is worth it to you for another $1700?

I think in your case the springs are primarily going to provide some insurance against overrev if you miss a shift or money shift it and catch it. Because you don't absolutely NEED the higher rate springs since your 964 cams are nothing super aggressive. And i'm not sure how much higher in revs you can expect to go when you have the stock rods (even with ARP bolts) and the original intake. That intake hits a pretty big wall at 6200, based on numerous dyno plots i've seen.

Let's not mix apples and bananas and oranges here when talking about internal modifications. Boat-tailing and mooning are modifications to the engine case and cylinders respectively. Only the highest of high strung engines see any benefit with those modifications. They're all about trying to smooth the airflow created inside the engine case from the rapid spinning of the crank and rods. Whereas the knife-edging is about lightening rotating mass (and cutting through the oil in a wet sump engine).

Actually you'd be surprised by the weights of new pistons. I measured my new JE pistons a handful of years ago and the spread of weight was 569.9 to 571.3 grams, including wrist pins. The factory spec book says the allowable variance for both Mahle and KS pistons is 4 grams. I think most doing a detailed build are usually shooting for all to be within 0.5 grams.

You're right that the crank certainly must be balanced in terms of having equal counterweights. But the crank remains balanced regardless of whether you're talking about unmolested counterweights or modified counterweights. Modifying the counterweights would of course absolutely require that the crank be re-balanced. Ignoring the actual & equal weight of the counterweights, the crank is going to be what's called internally balanced. However, the point i'm making is that the actual weight of the counterweights has importance and that's what Neil is referring to. Otherwise, why wouldn't the crank have the smallest of counterweights to begin with? Check this out for some more general technical detail about crankshaft balancing

Understanding Crankshaft Balancing - Engine Builder Magazine

That said, I think in Neil's article he's mixing two of his un-favorite things about the early crankshafts- modifying them by knifing AND the lack of a harmonic damper? But i'm not going to go correcting him because he knows way more about engine design than I could ever learn in five lifetimes. He has another article on his site about the importance of having a harmonic damper and I recall he doesn't like that the early engines don't have one. Look at the top/header of Neil's website page and put your pointer on the "Technical Articles" to see the other articles. The article about torsional dampers and the other about harmonic failure seem to be applicable to what we're talking about here.

I think what you're missing here is that the knifing has a negative effect on the crank. The counterweights are sized based on the weight of the pistons and the rods that the crank is throwing around. If you change the weight of the counterweights, then you technically should in turn change the weight of your pistons and rods to maintain that counterweight-to-piston+rods relationship. That said, I don't know that any of the DIY'ers here do that. We just throw different pistons (and sometimes rods) on our engines to hotrod them. Not an ideal thing to do, but seems to work OK because folks' crankshafts here aren't breaking all the time.
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Old 05-10-2018, 12:50 PM
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I doubt knife edging a crank will have any noticeable affect unless you have, say, titanium rods and are revving to 8K rpm.

If you want the motor to rev or respond faster a lightened flywheel / clutch will do more than knife edging.

Probably you would want to do some mods to the fuel injection system as well to get that quick revving motor, if that is your desire.
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Old 05-10-2018, 01:53 PM
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im not sure if removing weights from crank is a good idea for street motor in terms of longevity. i recall on the early 911, the hot models added more counter weights to the crank to counter the effects destructive harmonics for their motors with elevated revs.

honda B series type R motors that red lined at a stratospheric 8400 rpm 20 years ago also substantially added extra counter weights to keep the motor stitched together.

new modern motors run light cranks due to the ability to design out and isolate the origin of the harmonics.

Last edited by panzerfaust; 05-11-2018 at 08:01 AM..
Old 05-11-2018, 07:58 AM
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Originally Posted by panzerfaust View Post
im not sure if removing weights from crank is a good idea for street motor in terms of longevity. i recall on the early 911, the hot models added more counter weights to the crank to counter the effects destructive harmonics for their motors with elevated revs.

honda B series type R motors that red lined at a stratospheric 8400 rpm 20 years ago also substantially added extra counter weights to keep the motor stitched together.

new modern motors run light cranks due to the ability to design out and isolate the origin of the harmonics.
So here's what I've learned from researching this...
1.) I haven't found any info that stated that knife edging the crank has been the cause of any damage or decreased life expectancy of the engine.
2.) I haven't found any info that stated that knife edging has made the engine run better, faster, or stronger.
3.) Most say that this crank mod is mostly for larger V8s.
4.) the 600hp 3.x Porsche engines that are built by some of the best engine builders in the business have knife edged cranks. (of along with ALOT more mods)
5.) Finally... Ollie's engineering said that if there is one mod I would have them do, it would be to knife edge the crank. Not even boat tailing the mains, or mooning the cylinders.

So I guess having this done is like having a runner buy some heel molded gel insert with a curved inner sole because they think they will run faster with it.
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Old 05-13-2018, 04:37 PM
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I imagine that Porsche added the counter weights to counter the flexing of the crank at speed.

Remember the T models had cranks without counter weights. Those are safe to 6500 rpm.

The question I have for the gurus is this. Did Porsche ever knife edge any of their race cranks? What about the motors that had titanium rods? With less reciprocal mass would there be less counter weight needed?
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Old 05-13-2018, 06:04 PM
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On the subject of mooning of the cylinders. When i sent mine to L&N engineering to have them replated I wanted the this done to my cylinders. They told me that if you cut them into Mahle cylinders it creats a stress riser that willl make them crack and they dont recommend it. Thiers are manufactured with them in the cylinders already to prevent that. So I went with boat tailing but skipped having the cylinders moon cut.
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Old 05-14-2018, 05:17 AM
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The subject of knife edging cranks has been over many years, diluted into some sort of performance gain. Unfortunately, you get nothing for free.

Engine balance is about two main areas. Dynamic and harmonic. Both very different. Knife edging in my opinion is about dynamic balancing and the gains had with spinning a lighter mass within the engines block. Harmonic balance is about controlling the effects of the torque pulses aplied to the crankshaft.

Counter weights are placed on the crankshaft to control the counter forces as the pistons go up and down. You have two “moments” happening at the same time, rotating and reciprocating.
The depth of engineering is vast and requires some real understanding of what is going on and how to evaluate. Way too much of the average engine builder and I have tried to study this and have found some of it beyond my tiny brain’s capability.

Typically, in most in-line and V engines, the counterweight added to the crankshaft is 50% of the reciprocating mass. Porsche have reduced this due to the even balance of boxer engine design. We have even reduced this more in some of the performance engines we have built in the past, but there are side effects that need to be understood.

There is very little oil held in the engine case in these engines compared to wet sump engines. Secondly, what is held in the engine case is all stacked up against one side of the case and almost none in the path of the crankshaft. What is happening in a huge war between the oil being spun by the rotating crank and the air pressure pushing against it as the pistons retreat to BDC.

A crankshaft of lessor weight will accelerate quicker than a heavier crankshaft, that is simple physics. But that same crankshaft will be affected by the harmonic forces as it has less mass. The major critical changes to the crank’s ability to counter these harmonic forces is not changed by knife edging, but the total mass of the crank does have some effect.

The counter shaft (1st motion shaft) or intermediate shaft gear and the gear on the crank also cause and add some harmonics into this problem. Steel gears running against other steel gears without any sort of dampening crate huge harmonics, in some engines, “torsion bar” type dampers are included here. The old DFV has these.

I have always believed that when you make a modification, do so understanding the consequences. Don’t just do it because it is considered to be effective. Too many modifications done to Porsche engines are historic and since computer simulations have been available to us, many have been found to be ineffective and cause other issues.

Knife edge at your own peril but understand it is more about how it makes you feel than any gains found in the engine. I would spend more time controlling the cam timing due to a twisting crankshaft, and poorly designed camshaft profiles inducing harmonics into the valve train.

Since the late 80’s when I first was introduced to the 962C race engines, I have not seen a race crank in a Porsche engine with “knife edging”.

If you want the engine to accelerate quicker, maybe install lighter Pistons and Connecting rods. These two components have continued to be produced in their heaviest form since the 70’s, something we are changing with our new Piston and connecting rod designs.
Old 05-14-2018, 11:14 AM
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Shipping these to Ollies...
(on a side note, I was looking at getting titanium valves, but Del West engineering isn't answering their phone. )

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Old 05-14-2018, 11:38 AM
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I sent out my intake runners to Ollie's this week to have them clean them and polish the insides, as well as to port the intake mating points if needed so that the connection is seamless.
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Last edited by Trakrat; 05-17-2018 at 08:47 AM..
Old 05-17-2018, 05:19 AM
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Quote:
Originally Posted by Neil Harvey View Post
The subject of knife edging cranks has been over many years, diluted into some sort of performance gain. Unfortunately, you get nothing for free.

Engine balance is about two main areas. Dynamic and harmonic. Both very different. Knife edging in my opinion is about dynamic balancing and the gains had with spinning a lighter mass within the engines block. Harmonic balance is about controlling the effects of the torque pulses aplied to the crankshaft.

Counter weights are placed on the crankshaft to control the counter forces as the pistons go up and down. You have two “moments” happening at the same time, rotating and reciprocating.
The depth of engineering is vast and requires some real understanding of what is going on and how to evaluate. Way too much of the average engine builder and I have tried to study this and have found some of it beyond my tiny brain’s capability.

Typically, in most in-line and V engines, the counterweight added to the crankshaft is 50% of the reciprocating mass. Porsche have reduced this due to the even balance of boxer engine design. We have even reduced this more in some of the performance engines we have built in the past, but there are side effects that need to be understood.

There is very little oil held in the engine case in these engines compared to wet sump engines. Secondly, what is held in the engine case is all stacked up against one side of the case and almost none in the path of the crankshaft. What is happening in a huge war between the oil being spun by the rotating crank and the air pressure pushing against it as the pistons retreat to BDC.

A crankshaft of lessor weight will accelerate quicker than a heavier crankshaft, that is simple physics. But that same crankshaft will be affected by the harmonic forces as it has less mass. The major critical changes to the crank’s ability to counter these harmonic forces is not changed by knife edging, but the total mass of the crank does have some effect.

The counter shaft (1st motion shaft) or intermediate shaft gear and the gear on the crank also cause and add some harmonics into this problem. Steel gears running against other steel gears without any sort of dampening crate huge harmonics, in some engines, “torsion bar” type dampers are included here. The old DFV has these.

I have always believed that when you make a modification, do so understanding the consequences. Don’t just do it because it is considered to be effective. Too many modifications done to Porsche engines are historic and since computer simulations have been available to us, many have been found to be ineffective and cause other issues.

Knife edge at your own peril but understand it is more about how it makes you feel than any gains found in the engine. I would spend more time controlling the cam timing due to a twisting crankshaft, and poorly designed camshaft profiles inducing harmonics into the valve train.

Since the late 80’s when I first was introduced to the 962C race engines, I have not seen a race crank in a Porsche engine with “knife edging”.

If you want the engine to accelerate quicker, maybe install lighter Pistons and Connecting rods. These two components have continued to be produced in their heaviest form since the 70’s, something we are changing with our new Piston and connecting rod designs.
we said...

i recall knife edging were popular with american muscle cars that could benefit from this back in the 60's and 70's with the massive long stroke 90 degree cranks and deep wet sumps. then again those motors ran only to redline momentary or mere seconds on the 1/4 mile drag strips.

some of the older endurance italian race cars for instance knife edged their motors as well. the alfa 33 endurance racers lighten and knife edge their cranks on an already lighter v8 180 flat crank vs 90 degree but reloaded the weight back in the counterweights with heavy tungsten slugs. the nature of the track back then like le mans, mozna and spa, required to motor to sustain high rev for longer periods. these long straights are all gone today partitioned out with some sort of "senna chicanes". still they alfa have a stellar record of finishing races like porsche did whether is crank related or not. :-)

Last edited by panzerfaust; 05-18-2018 at 10:01 AM..
Old 05-18-2018, 09:56 AM
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Originally Posted by Trakrat View Post
Shipping these to Ollies...
(on a side note, I was looking at getting titanium valves, but Del West engineering isn't answering their phone. )
Titanium valves?
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Gordon
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Old 05-18-2018, 11:15 AM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #158 (permalink)
KTL KTL is offline
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Typically guys have found it worthwhile to have the 3.2 intake extrude honed to balance the flow amongst all the runners.

The titanium valves are nice choice to reduce the stress on the valve train. Reducing the valve mass goes a long way toward reducing the load on the valve springs. You also don't need excessively stiff springs when you use lighter valves. But keep in mind that you need to install new valve seats in the heads to properly cool the titanium valves. Titanium valves typically like copper-beryllium or nickel-aluminum-bronze seats
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Old 05-21-2018, 10:07 AM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #159 (permalink)
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