Which cam for my p38 4.6 on lpg ?

[zim]

Well, yesterday morning on my way to work my 4.6 crossed the 150,000 mile mark

I did the headgaskets about 5,000 miles ago due to it breaking between cylinder 6 and atmosphere. No water / oil mixing. It's been running fine since then Smile I did not get the block pressure tested for slipped liners etc, but i've not had any problems of loosing water or overheating Smile

However lately it's started to make a noise on startup for a short while. So i'm assuming the tappets need changing. Thus also needs a new cam as well.

What would you suggest ? I'm happy with the power it's got at the moment, but if i could have more or the same with better fuel or something i'll do that.

This is my daily driver (1995 Gems 4.6) with a single point gas system.

In m other v8 i've got a crower 50229 from paul @ v8tuner and am happy with that, but that's a toy truck I've emailed him about my p38 and he's recommended the Kent H180/200. http://www.v8tuner.co.uk/product.php?id=377

Thanks

Gordon

[Bowie69]

I have the H200(from Paul @ V8Tuner) in my 4.0 P38-engined RRC, this works well in my opinion, especially combined with the Rhoads lifters, which 'soften' the cam at lower revs in an effort to increase fuel economy, can't really give MPG figures, as it's not been running that long, and besides, this is *my* toy truck, so I tend not to monitor it too much

Your choice of cams are somewhat limited on the 4.0/4.6 serp V8s as not many manufacturers make them suitable for the different timing gear, you are also restricted to stock timing sprockets/chain, but they are an improvement over the plastic ones on the earlier V8s.

I would say either the H180/200 would be a good choice, mainly because you don't have much else, and the H200 does give oodles of grunt from around 2500rpm

[zim]

Cheers for the reply.

Did you ever run it a) on the standard ecu ? and b) with the original cam, so you can compare between before and after ?

I was just going to get a standard set of lifters to be honest, they should be ok shouldn't they ?

G

[Bowie69]

No, not on the original ECU, I swapped the MegaSquirt installation from the 3.9 over when dropping it in the RRC, but compared to the 3.9 it is a different engine altogether.

Standard lifters are fine, but if you have a racier cam, you can get a lumpy idle, to cure this you can up the idle a touch and it goes away, HOWEVER, if you have an autobox you then can't hold it on the brakes! By having the Rhoads lifters they bleed down under 3000rpm to give better cruising economy and smoother idle, IIRC they are about £60 more than stock ones. 

I found it worth it, as I have an auto box, I can maintain the idle ~750rpm and it's quite smooth

[p76rangie]

Well, yesterday morning on my way to work my 4.6 crossed the 150,000 mile mark

I did the headgaskets about 5,000 miles ago due to it breaking between cylinder 6 and atmosphere. No water / oil mixing. It's been running fine since then Smile I did not get the block pressure tested for slipped liners etc, but i've not had any problems of loosing water or overheating Smile

However lately it's started to make a noise on startup for a short while. So i'm assuming the tappets need changing. Thus also needs a new cam as well.

What would you suggest ? I'm happy with the power it's got at the moment, but if i could have more or the same with better fuel or something i'll do that.

This is my daily driver (1995 Gems 4.6) with a single point gas system.

In m other v8 i've got a crower 50229 from paul @ v8tuner and am happy with that, but that's a toy truck I've emailed him about my p38 and he's recommended the Kent H180/200. http://www.v8tuner.co.uk/product.php?id=377

Thanks

Gordon

I have had these guys cams in a number of 4.6 LPG cars and are more than happy with the results.

http://www.wadecams.com/

You have to look under "Leyland". I would have to look at what profile I have.

[zim]

Cheers for the reply.

When the rhodes bleed down, do they make a noise ?

G

[Hybrid_From_Hell]

^^

Nope,

I have them on the JED and you wouldn't know

H200 is a good cam for 4.6

Nige

[zim]

Ok

This is a reply email from paul "Difference between 180/200 cams is power delivery. Both are suitable for either 4.0 or 4.6 but the H200 has the emphasis on more midrange so is more of a Sports Road Cam. The H180 is the more suited to motorway cruising, towing and pulls better low down so good for towing and off-road."

So would i be better off with the 180 or 200 ?

G

[p76rangie]

Ok

This is a reply email from paul "Difference between 180/200 cams is power delivery. Both are suitable for either 4.0 or 4.6 but the H200 has the emphasis on more midrange so is more of a Sports Road Cam. The H180 is the more suited to motorway cruising, towing and pulls better low down so good for towing and off-road."

So would i be better off with the 180 or 200 ?

G

Assuming that you have an auto, the torque convertor looks after virtually all the power you need down low, so you are usually better going for something that will give you more midrange without making a rough idle.