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maroman360 03-30-2011 05:14:27 83.71.74.133 Report to Moderator	Howdy all, Looking for a bit of advice with regards to the engine in our 1999 Nh 8870. The tractor has cracked a piston, even though she is totally standard and putting out the correct rated power. I was wondering if anyone knows if the latest pistons available are improved/upgraded. I have been told that they have, and that there should not be a repeat failure with these new pistons. Just wondering if the block/pistons etc are any different in the 8870A/8970A, eg better under piston cooling etc. Any info would be greatly appreciated. [Reply]   [No Email]
maroman360 03-30-2011 17:11:52 83.71.74.133 Report to Moderator	Re: NH 8870 engine in reply to maroman360, 03-30-2011 05:14:27   You are right Nh014. It shows it as a piston kit for the 8870 and 8970 also. Am I correct in thinking that they are fitting these pistons to all models now? This post was edited by maroman360 at 17:33:15 03/30/11 2 times. [Reply]  [No Email]
nh014 03-31-2011 08:24:53 208.123.189.213 Report to Moderator	Re: NH 8870 engine in reply to maroman360, 03-30-2011 17:11:52   The 70-series are no longer in production, but all short blocks use the newest piston. [Reply]  [No Email]
maroman360 03-30-2011 17:07:07 83.71.74.133 Report to Moderator	Re: NH 8870 engine in reply to maroman360, 03-30-2011 05:14:27   Just typed that part no, 87801316, into the new holland parts website. It is coming up as a piston for the 86 and 8770. I thought that these pistons were even more notorious for breaking? Should it not be part no. 87801311? [Reply]  [No Email]
nh014 03-31-2011 06:36:48 208.123.189.213 Report to Moderator	Re: NH 8870 engine in reply to maroman360, 03-30-2011 17:07:07   You are correct, however, both kits are identical. When the 70-series tractors were introduced in 1993 the 8670 and 8770 used 1-5/8" piston pin, gravity cast pistons, and the 8870 and 8970 used the more durable 1-3/4" pin, squeeze cast pistons. The pistons for the 8670 and 8770 were upgraded twice, once to squeeze cast and secondly to 1-3/4". With that last upgrade, either kit will service the complete 70-series and 70A-series range from the 8670/8670A through the 8970/8970A. [Reply]  [No Email]
maroman360 04-01-2011 02:40:59 83.71.74.133 Report to Moderator	Re: NH 8870 engine in reply to nh014, 03-31-2011 06:36:48   Thanks for clearing that up NH014. Been hearing lots of conflicting reports from people but that seems to match what a reputable mechanic in the uk was suggesting. He also said that the quality was improved in the latest pistons, rather than a new design, and that they were much more reliable than the first pistons. Would you agree with that? [Reply]  [No Email]
maroman360 03-30-2011 16:57:13 83.71.74.133 Report to Moderator	Re: NH 8870 engine in reply to maroman360, 03-30-2011 05:14:27   Thanks for that nho14. We are going to get the injectors and pump checked over by a bosch specialist, and probably do some head work while we are at it. Tractor has about 5000hours on it and it just happened out of the blue. We also have an 8000 hour 8670 that gets a much tougher time and is still as good as new. Hope that the 8970 that you are talking about is the exception rather than the rule Bern!!! Our 8870 is pushing out around 220HP at the PTO and is absolutely standard. I dont even let her go more than 1/4 of the way up on the egt gauge. Its a strange one really, as I know of several 88 and 8970's with up to 20,000 hours on engines that have never been touched, and they would not be as well serviced as ours. [Reply]  [No Email]
nh014 03-30-2011 16:21:06 208.123.189.213 Report to Moderator	Re: NH 8870 engine in reply to maroman360, 03-30-2011 05:14:27   For all piston failures check the engine and fuel injection pump internal timing. Set to repair manual specifications. For all repairs use piston kit (part number 87801316) and re-sleeve the engine, or depending upon the severity of the damage, install a new short block. The kit includes the latest piston (with part number 87801267 stamped into the crown) and piston pin, retainers, and standard piston rings. These pistons use 1-3/4" wrist pins. The correct connecting rod with 1-3/4" bushings is 87801221. A new short block will have the latest pistons installed [Reply]  [No Email]
Bern 03-30-2011 15:24:22 66.218.202.59 Report to Moderator	Re: NH 8870 engine in reply to maroman360, 03-30-2011 05:14:27   I doubt it. I know of an 8970 on its 3rd set. [Reply]  [No Email]