Timing chain, Valve springs and ballance shaft Q

[4bait]

it runs at 4200rpm max it only did 6000 when the boat got air born some time ago and the prop left the water lol
it would clock up about 120 hrs per year and the average life of the chevy boat motors is around 1000 hours so I would expect about the same with this.

it handled 4200rpm nicely untill the springs broke and the piston decided to find a new home in the sump lol
If I could make it reliable with a revs around 4200rpm constantly then that would be nice.

Cheers Andy

 

[MACE]

I noticed you've come up with a much larger sump, good thing for engine longevity. Another thing which you could consider doing is to polish up the internal oil pump housing, to improve oil flow.

 

[4bait]

Hi Guys

Another Quick couple of Q's

Q1
I got a new unused double row timing chain of good old ebay, it was sold as, and came in, a roller master red label box but the cam gear is marked "JP 5620 Vr-VS" so it is obviously a JP set.
Is this normal in a roller master box or has the set been switched?

Q 2
the chain is not as tight as I expected it to be and will need a tensionor fitted but in other posts people have said dispose of the tensionor as it is not needed with the double row chain, so I am guessing maybe I should resell this set and purchase another on lol
The JP website only lists 5620 model for the engine so according to them it is correct.

I haven't got everything else here to do the build yet so have only sat it on the engine for a trail fit.
We are heading to Tassie for a couple of weeks R&R so will be placing a mace order when I get back for the valve springs etc

Cheers Andy

 

[acarmody]

JP and Rollmaster are the same company I believe.

 

[4bait]

JP and Rollmaster are the same company I believe.

Yeh reading through some other threads I am led to believe there are two types one uses a tensioner and one doesn't.
However some surfing on the net the JP site only lists one type so does Mace and the romac site is not very informative.

I have just placed an order with Mace for 130# Valve springs and retainers etc to take advantage of the Xmas coupon special deal so when they start back after the holidays will ask them.

Cheers Andy

 

[MACE]

Hey Andy,

The only difference between the Rollmasters and the JP’s are the chains (German chain Rollmaster, Indian chain JP). The sprockets are the same.

Do not use the chain tensioner with the double row item, as the chain tension will create many more problems then its worth.

Was the Rollmaster kit you received sealed?

Cheers
Steve

 

[4bait]

Thanks Steve

The box was not sealed, all items are new and look to be correct

The chain has about 10mm of hang as you can see in the pic and this relates back to 1.91 mm of cam sprocket backlash on the dial indicator.

Is this normal as to me this seems excessive and there is room for a tensionor to take up the slack.
I would have expected a tighter fit.

It may improve marginally when I replace the crank and cam bearings but it will be very minimal

Cheers Andy

 

[acarmody]

4bait, changing the bearing will make no difference with that sort of slack in the chain.

MACE, I have a tensioner with my double row, do you think I should get in there and take it off?

 

[MACE]

Thanks Steve

The box was not sealed, all items are new and look to be correct

The chain has about 10mm of hang as you can see in the pic and this relates back to 1.91 mm of cam sprocket backlash on the dial indicator.

Is this normal as to me this seems excessive and there is room for a tensionor to take up the slack.
I would have expected a tighter fit.

It may improve marginally when I replace the crank and cam bearings but it will be very minimal

Cheers Andy

Andy,

I’ve just opened up a rollmaster, factory sealed box, the chain is different (which is what I first suspected from the colour of the chain in the pics) and the sprocket has clearly engraved rollmaster on it. I’m 100% sure that you have a JP item, of which I recommend returning it for a refund. I’m hoping you purchased the item using paypal on ebay, as it should be relatively easy to get your money back. DO NOT use that chain setup!

Out of interest what is the angular displacement of the cam sprocket as it’s currently setup?

4bait, changing the bearing will make no difference with that sort of slack in the chain.

MACE, I have a tensioner with my double row, do you think I should get in there and take it off?

Get rid of it as soon as you can as they’re much harder on the chain tensioner then the factory item. You don’t want it to break up and end up in the sump.

 

[4bait]

Ok Just placed another online order with mace for a new roller chain set.

it will be my loss with the other one I guess, at least it wasn't a huge outlay.

Steve the pic shows everything set to TDC with the "0" keyway used on the drive cog, this was only bolted up to check the fitment it is not a final build or anything so the cam hasn't been dialled in or anything yet.

Now what else will I go back and buy of Mace now lol MMMMMMMM Some nice light alloy heads would be good

cheers Andy