Corvette Forum : DigitalCorvettes.com Corvette Forums banner

1 - 18 of 18 Posts

·
Registered
Joined
·
108 Posts
Discussion Starter #1
Hello.

I was going to go Crane all the way including their Gold race rockers 10750-16.



My builder - as did Grumpy before - suggested Comp Cams Ultra Pro Magnum rockers



This suggestion is for weight saving aspect. I believe both products are top of the line but what sort of weight differences are we talking about here? And does it matter in reality?
 

·
Super Moderator
Joined
·
8,547 Posts
Hello.

I was going to go Crane all the way including their Gold race rockers 10750-16.



My builder - as did Grumpy before - suggested Comp Cams Ultra Pro Magnum rockers



This suggestion is for weight saving aspect. I believe both products are top of the line but what sort of weight differences are we talking about here? And does it matter in reality?
both products are good and your unlikely to see problems with either choice,but its not about weight its about long term durability, steel has a significantly longer expected life span under conditions you'll see on the street and the difference in effective weight as the valve train is effected is minimal as the majority of the weights in the bearings and trunnion, you can run either rocker for years, but in the long term the fact that aluminum fatigues faster will eventually be a factor...it comes down to a compromise, the lighter rocker MIGHT allow you to make a couple more peak hp at the risk of slightly higher chance of an eventual rocker failure, you need to finish a race to win , or be able to depend on the car for transportation, so durability on an engine is more important than the potential of possibly making a couple peak hp
look, Ive run ERSON, CRANE, CROWER and COMP rockers on my engines, almost interchangeably for years, they all work much better than some of the cheap imports Ive seen, and all of them will last for years if your lube and cooling systems are functioning correctly and you do frequent oil changes, but if durability is the key factor.. I select the CROWER or COMP steel rocker
you might want to look into ERSON rockers IF both COST and light weight are more important to you.


http://www.pbm-erson.com/store.php?catId=24
 

·
Registered
Joined
·
108 Posts
Discussion Starter #3
I reckon I was in the back of my head comparing these investment cast chrome moly Ultra Pro Magnums to billet aluminum Cranes thinking that billet would be better in use.

I was searching the net for rocker arm failures and came across some Crane failures but not yet any CC UPM ones. They look definitely interesting.

Since the longevity is the main key here I will take your and his advise and go with these CC rocker arms.

Thanks Grumpy. :cheers:
 

·
Super Moderator
Joined
·
8,547 Posts
With these do you my any chance refer to stainless steel rockers such as this Crower



and this Comp Cams



all these rockers are steel
 

·
Registered
Joined
·
108 Posts
Discussion Starter #6
Sorry for not being able to express myself correctly. For me steel is steel ie. a blank or such after forging etc. and cast is cast even when it's cast steel of any sort and therefore we call them steel vs. cast.

I get your point now. :cheers:
 

·
Premium Member
Joined
·
369 Posts
you might want to look into ERSON rockers
Walde, If it makes any difference, these are the ones I went with per Grumpy's recommendation.
 

·
Super Moderator
Joined
·
8,547 Posts
Walde, If it makes any difference, these are the ones I went with per Grumpy's recommendation.
those are some of the most durable aluminum rockers available
Ive had them last in excess of 60K miles on several street sbc I built so they are a quality item
http://www.pbm-erson.com/store.php?catId=24

but Ive had the crower and comp steel rockers still good at 70k plus and still going strong, obviously the key to durability with any rocker is clean oil, low oil temps and low or moderate spring pressures and the correct valve train geometry
 

·
Registered
Joined
·
108 Posts
Discussion Starter #9
Walde, If it makes any difference, these are the ones I went with per Grumpy's recommendation.
Thx Ray. They seem quite reasonably priced, too.

I reckon I will go with the Comp Cams 1601-16 rockers as on top of everything else they are even in stock here.
 

·
Premium Member
Joined
·
369 Posts
I reckon I will go with the Comp Cams 1601-16 rockers as on top of everything else they are even in stock here.
They look really nice. I'll run the Ersons for a while and maybe switch to steel at some point, but if they last as long as Grumpy says, given the milage I do, I'll be long dead before they are.

Keep me posted on your progress. I've got all the major parts (crank. rods, pistons, damper) and now just waiting for a few bits and pieces. Hope to get the block to machine shop in the next couple of weeks.
 

·
Registered
Joined
·
108 Posts
Discussion Starter #11
Those Ersons do look bulletproof so I don't think you would ever have to replace them.

I believe it'll take at least week or two to have the block and rotating bits here. That'll give me some time to get all kinds of small parts such as ARP head bolts, oil pump, pan etc. etc. here.

What I have been meaning to ask you is that IIRC you said you bought a new GM flywheel. Do you have part number for it available? I think I'll change that and the clutch while at it.

Have you decided already what clutch you will use?
 

·
Premium Member
Joined
·
369 Posts
What I have been meaning to ask you is that IIRC you said you bought a new GM flywheel. Do you have part number for it available? I think I'll change that and the clutch while at it.

Have you decided already what clutch you will use?
Walde, I had ordered a Centerforce 700170 Flywheel and Stage II Clutch Kit, but they were on back order and Summit had no idea when they would ship from Centerforce. I wanted to get all the parts to the machine shop for machine work and balancing in one trip so changed my mind and went with the stock GM flywheel (part number 14088646) and McLeod MCL-75122 Clutch Kit as they were in stock. My original flywheel is most likely still good, just needs a resurface, but it's nice to have a new one. It actually is only 16 lbs. BTW! When I read that it was 16 lbs I couldn't believe it having taken it off a couple of times, but I put it on my scale and sure enough - 16 lbs..
 

·
Registered
Joined
·
108 Posts
Discussion Starter #13
Hmmm...this is the first time I've looked at these prices and they are a bit more than I expected or hoped for.

It's not even remotely comparable part to the GMPP flywheel but Rockauto has this Sachs NFW1004 OE replacement flywheel for 57 Euros and that is practically free. An AC Delco 388023 is appr. 90 Euros. These weigh in probably std 30 lbs but I don't know if I need a lightweight flywheel. Or lets say as it is: if I can afford one.

Do ours have dual mass flywheels or do those come with the ZF 6-speeds?

A good clutch is definitely something I need to invest in. A Sachs K191101 is about 120 Euros but I think it'll fry in minutes so have to consider that McLeod you chose.

And then I need also an oilpan.

Poor wallet... :thud:

:laughing:
 

·
Premium Member
Joined
·
369 Posts
Hmmm...this is the first time I've looked at these prices and they are a bit more than I expected or hoped for.

It's not even remotely comparable part to the GMPP flywheel but Rockauto has this Sachs NFW1004 OE replacement flywheel for 57 Euros and that is practically free. An AC Delco 388023 is appr. 90 Euros. These weigh in probably std 30 lbs but I don't know if I need a lightweight flywheel. Or lets say as it is: if I can afford one.

Do ours have dual mass flywheels or do those come with the ZF 6-speeds?

A good clutch is definitely something I need to invest in. A Sachs K191101 is about 120 Euros but I think it'll fry in minutes so have to consider that McLeod you chose.

And then I need also an oilpan.

Poor wallet... :thud:

:laughing:
Ours has a single mass flywheel. The heavier flywheel may even be better for parking lot speeds where things get a bit jerky.

Where in Europe are you located? I'm in England. What are you going to do for cam? Are you staying with the '86 block or are you getting a later roller block. I ask because if you're not going roller I have the Crane 114132 cam and lifter kit as well as a CompCams K12-268-4 kit that I'd planned to use on mine before I decided on retro-roller. Both brand new in box and I'm sure either would be cheaper than you could import or buy locally.
 

·
Registered
Joined
·
108 Posts
Discussion Starter #15
Up here and tad to the right from Sweden. :cheers:

I'm waiting for a Summit remanufactured roller block http://www.summitracing.com/parts/SUM-150100/ to arrive to the builder. If it is a quality piece with all the machinings etc. we will use it even if it would require a bit of work. If it's not then we'll see what we'll do. Unfortunately 4 bolt roller blocks do not grow in trees here.

I ordered the Crane 109671 this week as it looks to suit the other parts really well. Still a bit worried about the CR but we'll see. Actually, I did consider getting that 114132 but then things started to get out of hand badly... :laughing:
 

·
Premium Member
Joined
·
369 Posts
Up here and tad to the right from Sweden. :cheers:

I'm waiting for a Summit remanufactured roller block http://www.summitracing.com/parts/SUM-150100/ to arrive to the builder. If it is a quality piece with all the machinings etc. we will use it even if it would require a bit of work. If it's not then we'll see what we'll do. Unfortunately 4 bolt roller blocks do not grow in trees here.

I ordered the Crane 109671 this week as it looks to suit the other parts really well. Still a bit worried about the CR but we'll see. Actually, I did consider getting that 114132 but then things started to get out of hand badly... :laughing:
I understand, Walde. I considered one of those Summit blocks too as I would rather have kept my engine all original bagged up on a stand and built a new one from a good four bolt roller block. That Summit one looked great, but I couldn't swallow the shipping charges so decided to build my block. I said that once my block is decked I'll most likely lose the numbers from the engine pad and will no longer have a verifiable numbers matching Pace Car, but oh well.

Good luck with yours.
 

·
Super Moderator
Joined
·
8,547 Posts
I understand, Walde. I considered one of those Summit blocks too as I would rather have kept my engine all original bagged up on a stand and built a new one from a good four bolt roller block. That Summit one looked great, but I couldn't swallow the shipping charges so decided to build my block. I sad that once my block is decked I'll most likely lose the numbers from the engine pad and will no longer have a verifiable numbers matching Pace Car, but oh well.

Good luck with yours.

HINT, on fixing milled off numbers

http://www.harborfreight.com/3-lb-neon-orange-dead-blow-hammer-41799.html


http://www.harborfreight.com/36-piece-3-8-eighth-inch-steel-letter-number-stamping-set-35122.html
 
1 - 18 of 18 Posts
Top