30 replies to this topic

[Johno]

I’ve recently found out I have a chewed cam lobe on my 308 stroker.

Ive compression tested the engine and it came back around 120 on each cylinder.

I’m looking to find out what you think it might cost to get the engine rebuilt these days. I’d be looking to stroke it to 355 again with a lumpy hydraulic flat tappet cam and maybe 10:1 compression.

I’d likely want to get the HQ heads ported and opened up at the same time.

Any ballpark figure would be helpful, I can’t find much online about 308 rebuild packages. There used to be a lot of this but not anymore.

[yel327]

What are you thinking rebuild wise? Re-use the pistons and linish the crank if it's possible? Or new pistons, crank regrind etc?

 

Is it currently 350ci or 355ci? If its 355 it means its already 30 thou up, so if it needs reboring it may not go to 40 thou.

 

Basically what it will cost you depends upon what you intend to do during the rebuild.

 

Others here will give better guidance on HQ heads than I can.

[Johno]

It’s 355.

What do you mean it may not go to 40 thou? I thought they could go to 60 thou?

[yel327]

Some can. Some won't. Some overheat at +0.060". Some will go +0.080". It depends on the block, how corroded it is in the water jacket, and if it has core shift in any of the bores. You'd want to sonic/thickness test it if planning on spending money on it at 60 thou over. Many engine builders will tell you that a higher output 308/5.0L at 60 thou isn't a great idea, and even a stock 350/5.7L stroker will put a lot more load on the bores than a stock stroke 308/304 of similar usage will. 

[Johno]

That makes sense. Where do you think the best place would be to get a block? There’s not many 308s on Facebook for sale under 30 thou over. Perhaps I’d need to buy a dart block or some other aftermarket 308 block, if that’s a thing.

Or reluctantly switch to a 350 Chev.

Edited by Johno, 09 October 2023 - 08:03 AM.

[myss427]

That makes sense. Where do you think the best place would be to get a block? There’s not many 308s on Facebook for sale under 30 thou over. Perhaps I’d need to buy a dart block or some other aftermarket 308 block, if that’s a thing.

Or reluctantly switch to a 350 Chev.

 

No American made blocks, PAW do a block but they start at $7000

[rexy]

Why not replace the cam?

Is the engine in otherwise good condition?

[yel327]

Don't go buying anything until you get yours apart, it might hone and clean up at 40 thou. Or even be re-useable at 30 thou.

 

Plenty of VN-VS blocks around at standard bore. Wouldn't bother with Foolbook, look elsewhere.

[Johno]

I hear there’s a bit of a wait on PAW blocks also.

If I go to a 304 ect does that mean I have to add all the pollution gear?

Rexy the engine seems tired with 120 compression across all cylinders and I wonder how much of the metal from lobe has gone through it.

Just entertaining the thought of rebuilding the whole thing while we’re pulling things off it.

[Cook]

Hi Johno, I had an engine built for me about 5 years ago. I provided a QT 308 engine block and VN heads. Had it stroked to 355ci. It cost $10.5K. Here is some of the parts included.

sleeve 8 cylinders

relieve block for stroker

Scat - stroker crank

Scat - h-beam forged conrods

JE SRP - forged flat top pistons

camshaft - Lunati 10810703

valve spring kit with retainers & locs - Lunati Ovate Beehive

Hydraulic lifters - Lunati

timing kit - JP Racing

roller rockers - Comp Cams Magnum

High Volume JP oil pump

xp performance conrod bearings - King

xp performance main bearings - King

camshaft bearing set - Durabond

Harmonic Balancer Steel Street Power Bond

water pump assembly

 

Found the block needed re-sleeving but they looked after me with that. Hope that gives you some idea. Cheers Ron

 

PS 10:1 compression

Edited by Cook, 09 October 2023 - 08:38 AM.

[Johno]

Perfect, thanks Ron. About $10k was what I was hoping for but may be a bit more as yours was 5 years ago and I’ll need to do my heads.

Are there any risks/issues with resleeving?

Would that be an option for mine?

[yel327]

I hear there’s a bit of a wait on PAW blocks also.

If I go to a 304 ect does that mean I have to add all the pollution gear?

Rexy the engine seems tired with 120 compression across all cylinders and I wonder how much of the metal from lobe has gone through it.

Just entertaining the thought of rebuilding the whole thing while we’re pulling things off it.

 

It depends on when your LX was made. If its 6/76 or earlier, then only the canister and PCV system plus a few other things required. If after 6/76 (with ADR27A) then you need all the ADR27A stuff including the EGR valve if it's an auto anyway. The early 304 blocks (VK) aren't that much worse than ADR27A. A VL onwards would require Cats. But if you are rebuilding including decking the block then the date code on a 1993-1999 block looks the same as that on a 1973-1979 block.

[Cook]

I have no idea about potential issues etc. with resleeving but my engine builder didn't see it as a problem.  I guess it may depend on how hard you want to drive the car.  I considered it a potential benefit but that's just an uneducated opinion. Cheers Ron

[Johno]

Mines a 77 LX. Lots of good info here, Thankyou

Edited by Johno, 09 October 2023 - 09:13 AM.

[yel327]

If it's a 1977 then the pollution equipment is not really any different from then until the end of VK - it's basically the same stuff. That is if you are doing it to the letter of the law with regards to what is fitted.

[Johno]

Would a 304 require vn heads?

[Rockoz]

Heads are interchangeable provided you run the right camshaft for the heads.

 

Cheers

 

Rob

[yel327]

Would a 304 require vn heads?

 

HT through to VL heads are essentially the same, all that really differs is the absence of, or the shape of the EGR ports in the centre of the intake ports. Using the right intake manifold means it will fit any of these heads (note that HT and HG heads are missing one of the accessory holes on the head ends too). 304 started in VK and all VL are 304 as well. As Rob says you can also interchange VN-VSIII 304/350 heads onto HT to VL blocks, just have to change the cam, intake and exhaust manifolds plus the rocker covers. If you go the other way there are no valley head bolt bosses for HT to VL heads on VN-VSIII 304/350 blocks, although I don't think that matters.

[yel327]

I meant to add, if you are going to sleeve a block, there are a lot of cheap 60 thou up red and blue 5.0L blocks around. This thread I started a few weeks back, blocks are still listed, take your pick or buy the lot.

 

Cheap 308/5.0 blocks - E-Bay/AMC/Trading Post and other Offsite For Sale links - GMH-Torana

[Uncle Chop Chop]

Just remember that PAW block is a performance block, so emissions will be an issue. The COME block ( which may be ready ???) is a replacement block. So it will match whatever emission standards the vehicle has.

[Ice]

Mate of mine has a early 308 virgin bore its a 1975 block in Qld if you are interested i can flick you his number

I was  going to grab it but i dont need it anymore 

[dan097]

pull yours down and have a look, might get away with a flex hone, a good wash and another cam and lifters

as for the 120 comp check, if they were all even id say its fairly healthy. ive had engines with large camshafts comp check really low, just because of how inefficient they are at that low of an rpm

Edited by dan097, 10 October 2023 - 06:46 PM.

[Johno]

Thanks for all he info.

Fast forward to now. I bought a replacement second hand engine and upon inspection of the bores it had heavy scoring in one cylinder.

So I’m thinking about swapping the cam from the replacement engine and putting it in my original one as I was told it’s got 2000 kms on it and should be broken in. (I’m taking his word for it that it’s got 2000kms on it. The risk is the motor and cam actually never made it past break in before something went wrong. The manifold is super clean.)

I’m told this should be ok to do as long as I keep the lifters, pushrods ect in the same order they came out.

[yel327]

I wouldn't move the lifters from one block to another. I think its OK to re-use the cam but use new lifters. Others here will have intimate knowledge of this though.

[claysummers]

This will help avoid cam failure, I am told......
Or this one:

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