Penta heads

Post by **Carl** » 19 Dec 2006 08:17 pm

Are the Penta cylinder heads any different from automotive heads? My theory is that it's just the stuff bolted to them that's marinised, but would like a second opinion.

Cheers

Carl

Post by **volvorsport** » 19 Dec 2006 08:25 pm

no difference apart from the exhaust port on NO 4 , which has a steel ring

Post by **Carl** » 19 Dec 2006 10:42 pm

What do you mean by a steel ring?

Would a automotive manifold still fit ok?

Post by **volvorsport** » 20 Dec 2006 12:09 am

the steel ring is to prevent corrosion due to a water cooled exhaust .

everything fits fine .

Post by **Carl** » 20 Dec 2006 12:15 am

Ah I see, not too familiar with inboard marine engines. Thank you!

Post by **foggyjames** » 20 Dec 2006 01:49 am

There's little point in pursuing a marine cylinder head, as all the same stuff was available in car form, and will be in better shape. Salt water + ally = eek! The yanks go after AQ151s for their 531 8v heads, but we got 531s in cars, so we're ok. I have yet to be convinced of the wisdom of fitting a 531 to a B200, especially since the 530 is a better match to a B200 than a B230 anyway. Of course if this is for your B230...a 531 is a must-have

Certain Penta blocks on the other hand do contain some magic...

cheers

James

Post by **Carl** » 20 Dec 2006 01:55 am

Well it's a 531 head which I thought about mating up to the B230, as I wanna start stripping it down/inspecting/rebuilding soon and getting it ready for use. There's also a k-cam available to go with it. Both look to be in good nick.

But I've just found out some little f***ers have vandalised my other half's car, so I'm probably gonna have to pay for that to be sorted out, so probably no 531 head for me

Post by **foggyjames** » 20 Dec 2006 02:11 am

For a 531...I'd track down a car sourced one. Marine ones can be ok, but #4 port is a funny shape (courtesy of the anode ring Dave mentioned), and they're often totally screwed thanks to the salt water. I wish I knew where to start looking for the picture I'm thinking of...
Of course if this one isn't corroded, go right ahead...but do check all over for signs of corrosion (exhaust ports on marine ones, and the HG mating surface on both types - the holes should all be crisply defined.

The smart money is on one from an early (92-93) 940 with a B230FB 'hot tune' NA engine. They also came on almost all 740/760 Turbos - the ones with B230ET engines - but they are quite often in need of work by this age. Also make sure it really is a 531 if you're pulling it from a car - more than once I've been 'cheated' by a previous head-swap. The stamping is 1000531 (or 1000530) between #2 and #3 exhaust ports.

cheers

James

Post by **Carl** » 20 Dec 2006 02:17 am

Well there's no chance of me being able to see it, so I'll probably just leave it then.

I've not got any great want for one at the moment, I just saw it on ebay and thought it might be worth grabbing it. Anyway, I've got plenty of other engine parts to play with littered around the place!!

I didnt know n/a 940s came with the 531 head, I thought it was just the turbo 700s. Heh, might even have one already. I think my engine came from an early 940. Suppose I should check

Cheers for the 'heads' up.

Post by **foggyjames** » 20 Dec 2006 02:33 am

It's a good point...it might be an FB you have! The two of those I've pulled to date have both been super-clean....to the point where I'm very, very tempted to offer the guy I've "sold" one to the money back, as it hasn't yet shipped out, and I'd like one for my B230FK.

Unless it's super cheap (sub £20), I'd not bother. They're common enough from cars. I don't think I've ever paid more than £50, and many of those I haven't pulled myself. If you do pull one, do yourself and get a 1/2" drive 6 point 14mm socket for the head bolts....they're bloody tight, and I got fed up of breaking lesser sockets.

cheers

James

Post by **jtbo** » 20 Dec 2006 03:16 am

531 heads are expensive in here, 250€ at min. some with bigger valves are even 1500€, flight to UK and back is cheaper I think

Post by **Carl** » 20 Dec 2006 09:21 pm

jtbo - this is the one I was looking at:
http://cgi.ebay.co.uk/Volvo-penta-AQ131 ... 0064924746
You could always ask the guy if he'll send it to you. Could be a nice little money earner

The sockets I've got seemed to cope ok with the head bolts at Pete's - they were 6 point, but only cheap ones. And the bolts were godamn tight!!

Post by **foggyjames** » 20 Dec 2006 10:04 pm

To be honest Carl, that one actually looks very nice for a marine head. I'm going to go back on what I said, and suggest that that's a worthwhile buy.

cheers

James

Post by **Carl** » 20 Dec 2006 10:34 pm

Told ya

I'm still thinking about it, as Nat's car isn't as bad as I thought its was gonna be (£15 for a new window). But I really should be trying to save some money at the moment anyway.

The links there if anyone is interested. In the guy's other items the cam is of the k variety if anyone wanted that too.

Post by **foggyjames** » 20 Dec 2006 11:05 pm

I actually already sent him a question on that front...

cheers

James