TVR 500 Bottom Ends
Discussion
Ok... things are starting to get serious at the planning phase now that I'm rapidly generating funds to finance this madness of mine and I'm looking at the possibility of bottom ends to use for the engine.
Up until now I'd assumed I'd buy a 4.6L Rangerover engine and fit it with a 5L crank, forged rods and pistons and that'd be my bottom end sorted. I've been offered a TVR 500 engine out of a Chim that's in good nick and might be able to get it for a good price. I was just wondering how this would go as a bottom end when I'm running about a 420bhp engine.
This engine is going to be running completely refabricated stuff from the top of the block upwards (Wildcat heads, full fabriacted manifolds, injection system and ECU) so getting 420bhp shoudln't be a problem (thinking of adding a Vortech blower to bring a hundred or so more ponies to the party too).
Will the bottom end stand up to this kind of punishment? I'm planning on subbing in some forged rods and pistons so hopefully lack of strength won't be an issue. I've heard about issues with the blocks failing and leaking inside of the liners or the liners shifting altogether..... people have been known to fit top-hat liners to rectify this but this is expensive and is it really necessary? Anyone ever actually HAD this problem (everyone seems to know someone who knows someone who met a bloke in a pub once who had it happen to him).
Basically, I'm trying to map this out and see whether the premium I'm going to pay for the 5L TVR lump will be worth it given that I'm going to be using the block and crenk only really and the rest of it will probably be sold off.
Any help appreciated
Up until now I'd assumed I'd buy a 4.6L Rangerover engine and fit it with a 5L crank, forged rods and pistons and that'd be my bottom end sorted. I've been offered a TVR 500 engine out of a Chim that's in good nick and might be able to get it for a good price. I was just wondering how this would go as a bottom end when I'm running about a 420bhp engine.
This engine is going to be running completely refabricated stuff from the top of the block upwards (Wildcat heads, full fabriacted manifolds, injection system and ECU) so getting 420bhp shoudln't be a problem (thinking of adding a Vortech blower to bring a hundred or so more ponies to the party too).
Will the bottom end stand up to this kind of punishment? I'm planning on subbing in some forged rods and pistons so hopefully lack of strength won't be an issue. I've heard about issues with the blocks failing and leaking inside of the liners or the liners shifting altogether..... people have been known to fit top-hat liners to rectify this but this is expensive and is it really necessary? Anyone ever actually HAD this problem (everyone seems to know someone who knows someone who met a bloke in a pub once who had it happen to him).
Basically, I'm trying to map this out and see whether the premium I'm going to pay for the 5L TVR lump will be worth it given that I'm going to be using the block and crenk only really and the rest of it will probably be sold off.
Any help appreciated
Oh and just wanted to say that since I'm in NZ I'll be running without cats, and like I said I'll be running a full aftermarket injection system so pretty much all of the RV8 top end will be gone... I'm just questioning th ebenefit of building a mega horsepower RV8 using a TVR shortblock as the basis because IIRC most of the trickery in a TVR-RV8 is in the head porting, cam and injection system.
And yes, I'm definitely after 420bhp or similar so really getting that from just tweaking the TVR lump isn't going to be practically possible, hence why I'm starting from square one with the top-end.
And yes, I'm definitely after 420bhp or similar so really getting that from just tweaking the TVR lump isn't going to be practically possible, hence why I'm starting from square one with the top-end.
I saw a 4 litre engine which had liner problems .. V8 developments replaced all 8 for little money in real terms the car generated enough steam to satisfy even fred dibnah lmao!
I've heard good things about the power from wildcat heads, but also heard that they come badly finished and you have a lot of labour in making them fit for purpose .. check out Griffany's profile if you want to see great power from basically RV8 components .. makes you wonder if wildcat is worth the expense.
the car generated enough steam to satisfy even fred dibnah lmao! I've heard good things about the power from wildcat heads, but also heard that they come badly finished and you have a lot of labour in making them fit for purpose .. check out Griffany's profile if you want to see great power from basically RV8 components .. makes you wonder if wildcat is worth the expense.
You will probably be using a 90 mm stroke in which case it won't want to be a revver. I can't see you getting this power in n/a form. Now, with forced induction you can have your cake, keep mechanical stresses reasonable so long as you take care of temperature issues. You will also do it for less money and have massive mid range torque.
Yeah I'll be using the 90mm stroke, or possibly even greater and no, it's not going to be a revver.... even with forged internals I'm not looking to exceed 6000RPM... so that shouldn't be a problem. It's always going to be a torquemonster and that's what I'm after... I've heard some very good things about those little Vortech superchargers when used in unison with the RV8, nice, small, compact and do the job through the middle of the rev range.... couple it with a decent injection system that's able to keep up and of course enough cooling to keep everything in check during a NZ summer.... and she should be all go.... I think I should ask Rover NZ how much a brand new 4.0L block is gonna be, either that or buy a seond hand 4.0L engine and have it resleeved for safety and go from there..... The Wildcat heads aren't THAT expensive given that they come with rocker gear and everything.... expensive, yes, but not unrealistic.
A couple of experts I've talked to about the wildcat heads have not been at all complementary. The leading theory is the ports are too big and stall the air flow. Maybe they need a bigger bore induction system to work properly? I don't have any personal experience of them, has anyone else here?
When my engine was rebuilt they had to replace the liners .. Topo hats is what I got. I asked them to block test it and at noraml operating temps/pressures it was alright, but added another 10psi and it started to leak from one of the liners. ...
I have heard a 500 where he liner was coming up and down with the piston, nasty. Completely dislodged from the block.
I have heard a 500 where he liner was coming up and down with the piston, nasty. Completely dislodged from the block.
I know someone here in NZ using hem in a racing application in a Tuscan Racer and eats 800bhp porsches for breakfast (see PH article on Carl Hansen's Tuscan in NZ) but this is for a street application so I'll be taking the smaller port head rather than their "stage-2", track head.
As far as i've heard, the head starts off where a fully ported RV8 head leaves off in essence and as standard will flow a little better than about the maximum you can get out of a RV8 head. I'd imagine if you used the Wildcat head with the existing RV8 injection system or worse still, big carbies on a standard manifold, this may be the case as upstream restriction and big ports could cause flow-stall at low RPM..... with 8 individual throttle bodies and a free-breathing system all the way through with a 5L plus displacement, I'd say you'd be struggling to stall the flow on a pushrod, 8-valve design..... and as I said, I'm toying with adding a little bit of forced induction as well as these heads.... so that should help keep things moving nicely
As far as i've heard, the head starts off where a fully ported RV8 head leaves off in essence and as standard will flow a little better than about the maximum you can get out of a RV8 head. I'd imagine if you used the Wildcat head with the existing RV8 injection system or worse still, big carbies on a standard manifold, this may be the case as upstream restriction and big ports could cause flow-stall at low RPM..... with 8 individual throttle bodies and a free-breathing system all the way through with a 5L plus displacement, I'd say you'd be struggling to stall the flow on a pushrod, 8-valve design..... and as I said, I'm toying with adding a little bit of forced induction as well as these heads.... so that should help keep things moving nicely
johno said:
When my engine was rebuilt they had to replace the liners .. Topo hats is what I got. I asked them to block test it and at noraml operating temps/pressures it was alright, but added another 10psi and it started to leak from one of the liners. ...
I have heard a 500 where he liner was coming up and down with the piston, nasty. Completely dislodged from the block.
So you fitted the top-hats to FIX the leaking problem? or did the leaking continue AFTER the top-hat liners were fitted? I've heard horror stories of liners shifting and always believed it was possible and always thought top-hats were the answer to many of the RV8 head sealing problems as the head gasket seals to the liner rather than the alloy AROUND the liner.... allowing water to leak into the bores....
So your opinions of top-hat liners are....? And how much did it cost to get done? a fortune? or is it the sort of thing a good engine recon shop should be able to manage? Were the liners custom-made or off-the-shelf items?
I can't see what all the fuss is about with the top hat liners. Plenty of engines were built at 96mm using straight liners. If done properly there shouldn't be an issue. I suspect the top hats are just a way of fixing already condemned blocks and increasing capacity at the same time. If the gasket seals to the top hat there is still the step in the liner to seal? So do you need a gasket with a huge fire ring to seal everything? I'd buy a new block at 94mm and work from there. I can probably get you a counterbalanced long nosed crank from 86mm stroke to about 96mm if you need help.
David Hardcastle wrote an interesting book about tuning the Rover V8. He suggests (IIRC) that it might be better to consider a used block that has had the internal stresses worked out that using a brand new block.
My TVR block wasn't cross-bolted so you might want to consider having that done.
Ian A.
My TVR block wasn't cross-bolted so you might want to consider having that done.
Ian A.
Or, you can fit the ladder girdle. It works nicely and costs a lot less.
If there's a 4.6 block available to you then go for that if the price is good. The leaking liners seems to have been a thing with a certain batch of crossbolted engines. Later ones are reputed to be ok, so I've heard.
If there's a 4.6 block available to you then go for that if the price is good. The leaking liners seems to have been a thing with a certain batch of crossbolted engines. Later ones are reputed to be ok, so I've heard.
Hrmmm yeah I've thought about going with a girdle and dry sump.... the lower I can get the engine in the car the better.... the thing is there's not really any documented history with these engines... it's not like you know that there was a bad batch between engine #XXXXXXXXX and engine #XXXXXXXXX.... you're always running a risk 
I've ran turbos on stock stiff blocks with 96 mm bore and 5.1 capacity. I've also had a 4.5 which was blown. I ran both with the girdle and a mains stud kit with spacers under the girdle. I kept revs to 6k ish and never had a problem. I was also using a crank with 2" journals and stock rods. This kept it cheap as well.
Boosted.
Boosted.
Hmmmm interesting... so what sort of power outputs were you getting out of that?
What I'm planning to do is to machine up the bottom end of a crossbolt block nice and true and fabricate my own billet bearing caps to mate snugly with this, should keep everything square down below... add a dry sump, use a big journal crank to get 5+L capacity on a 94mm bore and just go with some decent rods and pistons from there.... the liners are the only thing I can't really make a firm decision on whether it's worth doing or not..... still have internal conflict to resolve before I buy anything.
What I'm planning to do is to machine up the bottom end of a crossbolt block nice and true and fabricate my own billet bearing caps to mate snugly with this, should keep everything square down below... add a dry sump, use a big journal crank to get 5+L capacity on a 94mm bore and just go with some decent rods and pistons from there.... the liners are the only thing I can't really make a firm decision on whether it's worth doing or not..... still have internal conflict to resolve before I buy anything.
I would certainly recomend the girdle for the bottom end it realy does tie all the short motor together, i would also recomend you go to 96mm top hat liners, this is certainly not going to be a low budget build if you are going down the wildcat heads road (trust me!!) and if you are buying aftermarket pistons you may as well get 96mm ones, it also helps the valve shrouding a hell of a lot on ians heads, my engine with the wildcat heads produces 450 bhp, i am a little confused on your rpm limit of 6k tho?? why go to the trouble of fitting these heads and loosing tons of low down and mid range power on rover heads to only rev to 6k? at that rpm figure you are only going to be making a few more bhp than you would with rover ones.
Well to be honest, I'd wanted a 6500/7000RPM rev limit to start but plenty of people have told me that on a stroker engine this is going to be too high and the engine will be a hand grenade.... you reckon that if the bottom end is stiff enough, forged internals and wildcat heads, what sort of rev limit is practical? Remembering this is a street engine, not a track engine so although I know it's going to be peaky compared to a standard engine, I still want it to be well useable for the street
Hi Rob,
I sent you an email
Anyway, this chap happens to live in NZ so he may be able to get some pretty good parts locally Also the blower (if he uses it) will help him produce very good mid range grunt and make the wildcats start working earlier. Don't know if you saw his post about using a blower.
Esprit, if the revs are stock then you don't need billet caps or anything expensive downstairs, just a stud kit and properly fitted girdle. Invest in quality forgings for boost, that's the place to spend the money. If you go for capacity then as Rob suggests go to 96 mm.
As for my engines, I don't know what power I had (rolling roads near me only go to 200 HP). It was the torque that was addictive. I like to think I had 400 hp plus with similar torque but who knows.
I sent you an email
Anyway, this chap happens to live in NZ so he may be able to get some pretty good parts locally
Also the blower (if he uses it) will help him produce very good mid range grunt and make the wildcats start working earlier. Don't know if you saw his post about using a blower. Esprit, if the revs are stock then you don't need billet caps or anything expensive downstairs, just a stud kit and properly fitted girdle. Invest in quality forgings for boost, that's the place to spend the money
. If you go for capacity then as Rob suggests go to 96 mm. As for my engines, I don't know what power I had (rolling roads near me only go to 200 HP). It was the torque that was addictive. I like to think I had 400 hp plus with similar torque but who knows.
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