355 stroker as a daily driver?

[Immortality]

Roller cams have more of a lumpy lobe where as flat tappets have more of an egg shape well one side of an egg and I guess the fat side of an egg is more like a roller cam. Rollers can't roll on a flat tapet as the point is too violent for the roller they need a nice smooth profile.
This leads to the square CM of area after intial lift and before final closing being more on a roller cam. A good flat tappet can out perform some roller cams but a good roller can't be beaten for mass air flow. But in most cases you don't need all the extra flow a roller cam provides so a flat tappet is fine to use they also sound a little more choppy imo which is what I prefer.

I like engines that sound like they're about to stall but keep on chuggin. Like a CAT RD6.

I know you have a hate for roller cams but don't put that on others. roller cams are more reliable than FT cams (due to modern engine oils which lack the additives FT cams like). Roller cams for the same given seat duration have more .050" duration and lift which gives better performance. A moderate hydro roller can make almost as much as the older solid FT cams without the hassles of a FT cam. FT cams are old school and have their place but his engine has a roller cam, going back to a FT cam is a step backwards.

 

[shane_3800]

I know you have a hate for roller cams but don't put that on others. roller cams are more reliable than FT cams (due to modern engine oils which lack the additives FT cams like). Roller cams for the same given seat duration have more .050" duration and lift which gives better performance. A moderate hydro roller can make almost as much as the older solid FT cams without the hassles of a FT cam. FT cams are old school and have their place but his engine has a roller cam, going back to a FT cam is a step backwards.

Sorry if you missread but I wasn't trying to make him change. I was explaining the advantage of roller cams vs flat tappet.
Most oil companies still sell high zinc oils for flat tappet cams like penrite's ten tenth racing oil. plus additives are avaliable.
Rollers have more valve duration but it's not always needed.

One of the best grinds is camtechs OE style grind for the 355 factory that made 215kw.

I don't have a hate for roller cams btw my last engine that died had a solid roller. One of the pistons shattered as they were **** pistons but I was made awear of solid rollers and there issue on the street of rollers skating at low engine rpm this issue is mostly solved with hyd rollers as they keep the roller on the cam even at 180deg from centerline with enough pressure to keep the roller rolling.
However you can daily drive a solid flat tappet.
all 4 styles of cams have there advantages and disadvantages.

 

[Immortality]

Yes, solid rollers have this issue but that is because of the lash which means when the roller is on the base circle of the cam there is clearance which can cause issues, hydro roller should not suffer this as there is always pre-load on the lifter to help keep said roller on the cam and doing it's thing. Solid roller is a different beast all together, these days most solid rollers are bushed and don't have needle roller bearing to help with this issue.

Yes, penrite sell their high zinc oil but not the regular manufacturers (Castrol, Shell etc). Modern oils have it taken out for EPA reasons and most people don't know that, especially when you read the label on the modern oils that say they are backwards compatible for older engines but in reality they aren't that great.

Rollers are great because you don't need as much .006 duration to have similar .050 duration which means the engine is more crisp (it doesn't bleed off cylinder pressure as much) which means for a given static CR you have a better dynamic CR or conversely you need a lower static CR to get the same performance as the older style FT cam. Rollers also should have more lift for a given duration so you get more flow. What I have noticed is that some cam suppliers are putting cams out in the market that don't make use of these benefits i.e roller cams that have similar slow ramp rates and total lift as the equivalent FT cam. If that is the case than you may as well stick with the FT cam, or find a supplier that has better cam specs. Camtech has some good grinds.

It really is a fascinating subject but many experts don't like to share but it you see some of the stuff from the likes of HPE Pete and TK383 they are picking cams not so much on just duration but rather picking lobe profiles from the master catalogue to target lift to make use of the intake port area they spend so much time carefully grinding.

 

[shane_3800]

Yea the part about flat tappets bleeding off pressure and needing more static CR is why I think they sound better ecspecially carbed as the vac signal gets screwed up and makes them idle mean.

 

[Immortality]

Just close up the LSA, that'll make it angry at idle

 

[TimEmpire]

Sorry if you missread but I wasn't trying to make him change. I was explaining the advantage of roller cams vs flat tappet.
Most oil companies still sell high zinc oils for flat tappet cams like penrite's ten tenth racing oil. plus additives are avaliable.
Rollers have more valve duration but it's not always needed.

One of the best grinds is camtechs OE style grind for the 355 factory that made 215kw.

I don't have a hate for roller cams btw my last engine that died had a solid roller. One of the pistons shattered as they were **** pistons but I was made awear of solid rollers and there issue on the street of rollers skating at low engine rpm this issue is mostly solved with hyd rollers as they keep the roller on the cam even at 180deg from centerline with enough pressure to keep the roller rolling.
However you can daily drive a solid flat tappet.
all 4 styles of cams have there advantages and disadvantages.

I havn't heard Camtech cams mentioned much so this was interesting to me as I've only just had the V8 from my VR Calais stroked and rebuilt/converted to a roller cam and I've used the 49907 Camtech hydraulic roller cam which I think is the next step up. I've not been able to find an example of anyone having used this before and would be interested in knowing how they perform as they car probably won't be driveable until Christmas. I believe the OE style is 212/222 duration @.050 with 534/559 lift, mine is 223/227 duration @.050 with 582/582 lift.

 

[Immortality]

I don't think the OEM roller cam in the VT motors was anywhere that big.

 

[losh1971]

Make sure you fit decent exhaust, once you do we need a 3min vid of it idling and a couple of light throttle movements, plus maybe a driving off shot as well..... I'll look forward to that.....

 

[shane_3800]

I havn't heard Camtech cams mentioned much so this was interesting to me as I've only just had the V8 from my VR Calais stroked and rebuilt/converted to a roller cam and I've used the 49907 Camtech hydraulic roller cam which I think is the next step up. I've not been able to find an example of anyone having used this before and would be interested in knowing how they perform as they car probably won't be driveable until Christmas. I believe the OE style is 212/222 duration @.050 with 534/559 lift, mine is 223/227 duration @.050 with 582/582 lift.

If you can have more cam it's better. But if your engine is fairly stock the powerband on the camtech is insane.

 

[TimEmpire]

If you can have more cam it's better. But if your engine is fairly stock the powerband on the camtech is insane.

I chose that cam specifically because the powerband is 1800-5800 and wouldn't require me running a stall convertor (just requires at least 9.5:1 compression and 3.5:1 diff ratio, my engine has been rebuilt to 10.5:1 compression). The next cam up shifts the range to 2500-6000 and requires a stall convertor but I didn't see the extra 200rpm at the top end being worth the trade-off as I live in the city and will be daily driving 5-6km to work dealing with traffic lights etc.

That being said it's definitely not close to stock anymore, stroked to 355 with SRP pro forged pistons, acl race mains, flat tappet to roller cam conversion, single piece stainless valves, double race springs, platinum roller rockers, custom made twin throttle body intake manifold (two standard forward facing throttle bodies) etc. It's also going to be running an upgraded VT alternator with electric fans and davies craig electric water pump and controller. It's been at the shop for nearly a year now and I'm about 3-4 weeks from getting it dyno'd so I'm frothing to see what sort of power it makes, keeping in mind the goal was to make it as driveable as possible and not just aim for high horsepower numbers.